Table of Contents
Introduction
In recent years, two medicines have become some of the most talked about treatments for type 2 diabetes and weight management: Ozempic® (semaglutide) and Tirzepatide (sold as Mounjaro® and Zepbound®). These medicines belong to a group of drugs that help control blood sugar and, at the same time, can lead to significant weight loss. Because both are highly effective, many patients and doctors are asking the same question: how do their side effects compare, and what should patients know before starting one of them?
To understand why people compare these medicines, it helps to know a little about how they work. Ozempic® belongs to a class called GLP-1 receptor agonists. These drugs copy the action of a natural hormone in the body called GLP-1, which helps lower blood sugar after meals, slows down digestion, and reduces appetite. Tirzepatide, on the other hand, is slightly different. It is a dual GIP and GLP-1 receptor agonist. This means it mimics two hormones—GLP-1 and GIP. GIP is another hormone involved in insulin release and appetite regulation. Because Tirzepatide works on both hormone pathways, researchers believe it may provide stronger effects on weight and blood sugar. However, these differences in how the drugs act inside the body may also explain why side effects are not always the same.
When people search for information online about Ozempic® or Tirzepatide, they often want to know about side effects first. This is understandable. While lowering blood sugar and losing weight are important, the way a medicine makes a person feel day to day can strongly affect whether they continue to take it. For example, nausea, vomiting, and stomach upset are common concerns. Others worry about more serious risks such as pancreatitis, gallstones, or rare warnings about thyroid cancer. Because both drugs work on hormones that affect digestion, many patients wonder whether one is easier to tolerate than the other.
The Food and Drug Administration (FDA) carefully reviews clinical trials before approving medicines like Ozempic® and Tirzepatide. In these studies, thousands of people take the drug and are closely monitored for side effects. The results are then listed on the medication’s prescribing label. But real life often adds another layer. After a drug is used by millions of people outside of controlled studies, doctors and patients may notice new patterns. Sometimes, a side effect that seemed rare in trials becomes more noticeable in the wider population. For this reason, it is important to look not only at what the official trials say but also at what ongoing monitoring and research are finding about both drugs.
This article is designed to give patients and caregivers a clear, side-by-side understanding of Ozempic® and Tirzepatide when it comes to side effects. The goal is not to promote one medicine over the other but to explain the facts as carefully and simply as possible. By comparing them, patients can feel more prepared when they discuss treatment choices with their healthcare providers.
We will explore common side effects, such as stomach upset and constipation, and compare how often they occur in each drug. We will look at risks related to blood sugar, like hypoglycemia, especially when these drugs are combined with other diabetes medications. We will also go into more serious but less common concerns, such as pancreatitis, gallbladder disease, and cardiovascular effects. Finally, we will explain how long-term use is studied, what is known so far about safety over years, and why dose adjustments matter.
Understanding side effects does not mean that patients should avoid these medicines. In fact, many people tolerate them well and see life-changing benefits. But it does mean that being informed helps patients notice warning signs early and know when to talk with their doctor. Every person is different, and what may be a small side effect for one person might feel unbearable for another. That is why medical guidance and careful monitoring are always necessary.
By the end of this article, readers will have a complete picture of how Ozempic® and Tirzepatide compare when it comes to side effects. The information is based on medical studies, FDA safety warnings, and scientific evidence, not on personal opinions or single experiences. The purpose is to give patients knowledge they can use to make safer and more confident decisions about their health.
How These Medications Work
When comparing Ozempic® (semaglutide) and Tirzepatide (sold as Mounjaro® for diabetes and Zepbound® for weight management), it helps to first understand how they work inside the body. Both drugs are given by injection and are part of a new group of medicines that help with type 2 diabetes and weight loss. While they have some similarities, they also have important differences that may explain why their side effects are not the same.
Ozempic®: A GLP-1 Receptor Agonist
Ozempic® contains semaglutide, which is called a GLP-1 receptor agonist. GLP-1 stands for “glucagon-like peptide-1,” which is a hormone naturally made in the gut after eating. This hormone helps the body in three main ways:
- Slows down stomach emptying – Food leaves the stomach more slowly, which helps people feel full for longer after a meal. This effect is one reason why nausea or bloating can occur.
- Boosts insulin release – GLP-1 helps the pancreas release insulin, but only when blood sugar is high. This lowers blood sugar in people with type 2 diabetes.
- Lowers glucagon release – Glucagon is another hormone made by the pancreas that raises blood sugar. By lowering glucagon, Ozempic® helps prevent spikes in blood sugar after meals.
Because it mainly works through these gut and pancreas pathways, Ozempic® can cause gastrointestinal (GI) side effects such as nausea, vomiting, or diarrhea, especially when the dose is first increased.
Tirzepatide: A Dual GIP and GLP-1 Receptor Agonist
Tirzepatide is different. It is called a dual GIP and GLP-1 receptor agonist. This means that it acts on two types of gut hormones:
- GLP-1 (same as semaglutide) – Like Ozempic®, Tirzepatide slows down stomach emptying, increases insulin release, and lowers glucagon.
- GIP (glucose-dependent insulinotropic polypeptide) – This is another natural gut hormone that also plays a role in blood sugar control and fat metabolism.
By activating both GLP-1 and GIP receptors, Tirzepatide appears to have a stronger effect on lowering blood sugar and supporting weight loss. In clinical studies, people taking Tirzepatide often lost more weight and saw greater improvements in A1C (a measure of long-term blood sugar control) compared with those on semaglutide.
Why the Differences in Mechanism Matter
Because Tirzepatide works on two hormone pathways instead of one, its side effect profile may look a little different from Ozempic®. Here are a few reasons why:
- Stronger effects on appetite and digestion – Both drugs slow stomach emptying, which can lead to feelings of fullness, nausea, or constipation. But with Tirzepatide, this effect may be stronger because of its dual action, especially during dose increases.
- Metabolic changes – GIP activity may add benefits in fat storage and fat breakdown, but it could also bring new side effects we do not see as often with semaglutide alone.
- Different tolerability – Some patients find they tolerate Ozempic® better, while others do better on Tirzepatide. The reason may come down to how their bodies respond to the dual hormone action.
What This Means for Patients
Understanding the science behind these medicines helps explain why both are effective and why side effects happen. Patients often ask why they feel nausea, bloating, or changes in bowel habits. These effects are directly tied to how the drugs slow digestion and change hormone signals.
Another key point is that both Ozempic® and Tirzepatide work only when blood sugar levels are high. This is why, when used alone, they usually do not cause dangerously low blood sugar (hypoglycemia). Low blood sugar becomes more likely only when the medicines are combined with insulin or drugs that push the pancreas to release more insulin.
Common Gastrointestinal Side Effects
When people start taking medicines like Ozempic® (semaglutide) or Tirzepatide (sold as Mounjaro® for diabetes and Zepbound® for weight management), the most common side effects happen in the digestive system. These are called gastrointestinal, or “GI,” side effects. They include nausea, vomiting, diarrhea, constipation, and abdominal (stomach) pain. These symptoms happen because both medicines slow down how fast the stomach empties food and because they change how the gut responds to eating. Let’s look at each effect in detail and compare what studies show about the two medicines.
Nausea
Nausea is the most reported side effect with both Ozempic® and Tirzepatide. It can feel like queasiness or an unsettled stomach, especially after eating. In large clinical trials, up to 20–30% of people using Ozempic® reported nausea, while the rate for Tirzepatide varied by dose, ranging from around 15% at lower doses to over 25% at higher doses.
For most patients, nausea is worse when first starting treatment or when the dose is increased. Over time, the body often adjusts, and the nausea becomes milder or goes away. Doctors usually recommend starting at a low dose and slowly increasing it to help reduce this side effect. Eating smaller meals, avoiding fatty or greasy foods, and drinking clear fluids can also help.
Vomiting
Vomiting is less common than nausea but can still occur. Vomiting tends to happen in the first few weeks of treatment, especially if the dose is increased too quickly. About 5–10% of patients on Ozempic® experience vomiting. For Tirzepatide, the rates are similar but can go slightly higher at stronger doses.
Repeated vomiting can be concerning because it may lead to dehydration or loss of important electrolytes like sodium and potassium. If vomiting continues or becomes severe, patients are advised to contact their healthcare provider. In rare cases, a dose reduction or stopping the medication may be necessary.
Diarrhea
Diarrhea is another common GI effect. Clinical data show that about 8–10% of patients on Ozempic® experience diarrhea. With Tirzepatide, the rates are often slightly higher, reported in up to 12–15% of users depending on dose.
Diarrhea can range from mild to bothersome. It may last only a few days, or it may come and go during treatment. Because both medicines slow digestion, food stays longer in the gut, which can sometimes cause changes in bowel movements. Staying hydrated and eating bland foods can reduce discomfort.
Constipation
Constipation may seem surprising since diarrhea is also a common complaint, but both can happen. Ozempic® causes constipation in about 5–7% of patients. Tirzepatide’s rates are a little higher, closer to 6–8%. Constipation can be uncomfortable, leading to bloating, stomach cramps, or straining during bowel movements.
Simple steps like drinking more water, eating high-fiber foods, and staying active can help. In some cases, a mild stool softener may be suggested by a healthcare provider.
Abdominal Pain
Some patients report abdominal pain, bloating, or general stomach discomfort. This is linked to slower stomach emptying and changes in gut hormones. Pain is usually mild to moderate, but in some cases, it may be more noticeable. Clinical trials show similar rates of abdominal pain between Ozempic® and Tirzepatide, usually affecting 5–9% of patients.
If the pain becomes severe or does not improve, it’s important to seek medical advice, since stomach pain can sometimes signal other problems, like gallstones or pancreatitis, which are more serious side effects.
Severity Differences Between Ozempic® and Tirzepatide
Although both medicines cause GI side effects, some studies suggest that Tirzepatide may cause slightly higher rates of nausea, diarrhea, and constipation at higher doses compared to Ozempic®. However, the differences are not extreme, and many patients tolerate both medications well once they adjust.
Importantly, side effects are dose-related. Higher doses give stronger weight loss and blood sugar control, but they also increase the chance of stomach upset. This is why doctors carefully plan how to increase the dose step by step.
Tips Doctors Often Share with Patients
Healthcare providers often recommend practical steps to manage GI side effects:
- Eat smaller meals and avoid overeating.
- Reduce fatty, greasy, or spicy foods, which can trigger nausea.
- Drink water throughout the day to stay hydrated, especially if vomiting or diarrhea occurs.
- Eat bland foods like toast, crackers, or bananas when the stomach feels unsettled.
- Report severe or ongoing symptoms to the care team, since sometimes a dose adjustment is needed.
The most common side effects of Ozempic® and Tirzepatide are gastrointestinal—nausea, vomiting, diarrhea, constipation, and abdominal pain. While these effects are uncomfortable, they are usually temporary and improve as the body adapts. Both medicines share a very similar side effect profile, though Tirzepatide may cause slightly more GI issues at higher doses. With careful dose titration and support from healthcare providers, many patients are able to continue treatment successfully.
Weight Loss and Side Effects: Is One Harder to Tolerate?
One of the biggest reasons people are interested in Ozempic® (semaglutide) and Tirzepatide (sold as Mounjaro® for diabetes and Zepbound® for weight management) is their ability to help with weight loss. Both medicines belong to a class of injectable drugs that change the way the body handles blood sugar and appetite. While they are very effective, the side effects—especially stomach-related side effects—can sometimes make treatment difficult to continue. This section looks closely at how weight loss from these drugs connects to side effects, whether one is harder to tolerate than the other, and what studies have shown about people stopping treatment because of these problems.
Weight Loss and the Body’s Adjustment
When people lose weight quickly, the body goes through many changes. Hormones, digestion, and even the gallbladder must adjust. For medicines like Ozempic® and Tirzepatide, the weight loss effect is partly due to reduced appetite and slower digestion. This slowdown in how food leaves the stomach can make a person feel fuller, but it also increases the chance of nausea, bloating, and sometimes vomiting.
Tirzepatide often leads to more weight loss than Ozempic® at similar treatment times. In clinical trials, many people on Tirzepatide lost between 15% and 20% of their body weight after a little over a year, while Ozempic® users often lost around 10% to 15%. This difference sounds exciting, but stronger weight loss may also mean stronger side effects, at least during the first months of use.
Gastrointestinal Side Effects and Weight Loss
The most common side effects linked to both drugs are gastrointestinal (GI) issues. These include:
- Nausea: Feeling sick to the stomach, especially after meals.
- Vomiting: More likely if meals are large or fatty.
- Diarrhea: Loose stools that can lead to dehydration if severe.
- Constipation: Hard stools or difficulty passing bowel movements.
- Stomach pain or discomfort: Pressure, cramping, or bloating.
Both Ozempic® and Tirzepatide can cause these problems, but studies suggest Tirzepatide may cause slightly more nausea and diarrhea. On the other hand, Ozempic® sometimes causes more constipation. These side effects tend to appear during the first weeks or months of treatment, especially when the dose is increased.
Rapid Weight Reduction and Side Effects
Because Tirzepatide often produces faster weight loss than Ozempic®, some researchers believe that the body’s quicker adjustment period may increase side effects. When weight drops quickly, the gallbladder has to work harder, which can increase the risk of gallstones. The digestive system also adapts to eating smaller amounts of food, which may worsen feelings of fullness or nausea.
However, it is important to remember that side effects usually improve with time. In most people, the stomach and intestines adjust after several weeks, and nausea or vomiting lessen. Doctors often recommend eating smaller meals, avoiding greasy foods, and drinking water slowly throughout the day to help reduce these symptoms.
Discontinuation Rates in Clinical Trials
One way to measure how tolerable a medicine is involves looking at how many people stop taking it because of side effects. In trials, a small percentage of patients stopped both Ozempic® and Tirzepatide due to gastrointestinal problems. The rates are not very high—most people were able to continue treatment—but Tirzepatide had slightly more discontinuations in some studies.
For example:
- In major weight loss studies, about 5% to 7% of participants using Ozempic® stopped because of side effects.
- In similar studies of Tirzepatide, about 6% to 8% stopped for the same reason.
This means that while Tirzepatide may be linked with more side effect-related dropouts, the difference is not huge. The majority of patients continued with either drug.
Patient Experience Over Time
Another important point is that tolerance usually improves the longer a person is on the medicine. At first, side effects may be tough, but with slow dose increases and time, most people can continue. Both Ozempic® and Tirzepatide have dose schedules that start low and go up step by step, usually every four weeks. This gradual increase is designed to give the body time to adjust, lowering the risk of strong side effects.
Doctors may also advise pausing dose increases if side effects are severe. For some patients, staying at a lower dose for a longer time before moving up can make the medicine easier to tolerate.
Both medications are powerful tools for weight loss, but side effects—especially stomach-related ones—can be challenging in the first few months. Tirzepatide may lead to faster results but can be slightly harder to tolerate for some people. With medical guidance and gradual dose increases, many patients are able to manage side effects and stay on treatment.
Blood Sugar-Related Concerns
Both Ozempic® (semaglutide) and Tirzepatide (Mounjaro® / Zepbound®) are medicines used to lower blood sugar in people with type 2 diabetes. They can also be prescribed for weight management. While these medicines help many people, patients often wonder how they affect blood sugar levels and whether they can make blood sugar go too low. This section explains the risks and what research shows.
How Ozempic® and Tirzepatide Lower Blood Sugar
Both drugs work by copying natural gut hormones that signal the pancreas to release insulin when blood sugar rises. Insulin lowers blood sugar by helping the body move sugar into the muscles and liver for energy or storage.
- Ozempic® copies the hormone GLP-1 (glucagon-like peptide-1). It makes the pancreas release insulin after meals and slows down how quickly food leaves the stomach.
- Tirzepatide is different. It copies two hormones: GLP-1 and GIP (glucose-dependent insulinotropic polypeptide). The extra hormone action may give it a stronger effect on blood sugar control and weight loss.
Because these medicines only trigger insulin release when blood sugar is high, the risk of very low blood sugar (called hypoglycemia) is lower than with older drugs like sulfonylureas or insulin by itself. But the risk is not zero.
What Is Hypoglycemia?
Hypoglycemia means blood sugar is too low, usually below 70 mg/dL. Symptoms can include:
- Shaking or sweating
- Dizziness or headache
- Fast heartbeat
- Hunger
- Irritability or confusion
Severe hypoglycemia can cause fainting, seizures, or even death if not treated quickly.
Risk of Hypoglycemia With Ozempic® Alone
Studies show that people who take Ozempic® by itself have a low chance of severe hypoglycemia. Most episodes are mild. This is because the drug’s insulin release depends on food intake and blood sugar levels. If sugar levels are already normal, Ozempic® does not force the pancreas to make more insulin.
Risk of Hypoglycemia With Tirzepatide Alone
Tirzepatide also has a low risk of causing severe hypoglycemia when taken alone. In major clinical trials, less than 1% of patients had serious low blood sugar episodes. Most mild events happened in people who skipped meals or had very low calorie intake.
When the Risk Increases: Combination With Other Medicines
The biggest concern for both Ozempic® and Tirzepatide is when they are used together with other diabetes medicines that lower blood sugar.
- Insulin: Both drugs increase the risk of hypoglycemia when combined with insulin, because insulin can push blood sugar down even if it is already normal. Doctors often lower the insulin dose when starting one of these drugs.
- Sulfonylureas (such as glipizide, glyburide, or glimepiride): These older pills make the pancreas release insulin even if blood sugar is not high. When combined with Ozempic® or Tirzepatide, the chance of low blood sugar increases.
For this reason, patients on insulin or sulfonylureas are usually told to watch their blood sugar more often and may need lower doses of these older medicines.
Comparing Hypoglycemia Rates Between the Two Drugs
Head-to-head data is limited, but large trials show:
- Ozempic® and Tirzepatide both have low risks when used alone.
- Tirzepatide may lower blood sugar more strongly than Ozempic®. Some experts believe this could slightly increase the risk of hypoglycemia, especially if combined with other medicines, but overall rates remain low.
- In clinical trials, most hypoglycemia cases occurred when patients were also on insulin or sulfonylureas, not when they took these drugs alone.
Safety for People With Type 2 Diabetes vs. Weight Loss Use
- In Type 2 Diabetes: Both drugs are safe choices, but people who also use insulin or sulfonylureas must be cautious. Doctors often adjust doses to reduce the risk of low blood sugar.
- For Weight Management (without diabetes): Since these patients are not taking insulin or sulfonylureas, the risk of hypoglycemia is very low. This is one reason these medicines have been approved or studied for weight loss.
What Patients Should Know
- Monitor blood sugar: If you have diabetes, check your levels as recommended, especially when starting or changing doses.
- Know the symptoms: Learn how to spot early signs of hypoglycemia.
- Carry fast-acting sugar: Keep glucose tablets, juice, or candy nearby in case blood sugar drops suddenly.
- Talk with your doctor: Always ask about adjusting insulin or other diabetes drugs when starting Ozempic® or Tirzepatide.
On their own, Ozempic® and Tirzepatide rarely cause dangerous low blood sugar. The risk becomes higher when they are used with insulin or sulfonylureas. Careful dose adjustments and regular monitoring make these medicines safe and effective for most people. Patients should always work closely with their healthcare team to balance blood sugar control with safety.
Pancreatitis and Gallbladder Risks
Both Ozempic® (semaglutide) and Tirzepatide (sold under the brand names Mounjaro® and Zepbound®) work in the digestive system to help lower blood sugar and promote weight loss. Because they affect how the stomach, pancreas, and gallbladder work, doctors carefully monitor for problems in these organs. Two of the most important risks that patients often hear about are pancreatitis and gallbladder disease. While these side effects are not common, they can be serious and need careful understanding.
What is Pancreatitis?
The pancreas is an organ behind the stomach that makes digestive juices and insulin. Pancreatitis means inflammation of the pancreas. When this happens, the pancreas becomes irritated and swollen. Symptoms can be mild or severe.
Common signs include:
- Sudden and strong stomach pain, often felt in the upper belly or moving into the back.
- Nausea and vomiting.
- Fever.
- A fast heartbeat.
Severe pancreatitis may require hospital care and can sometimes lead to dangerous complications.
Pancreatitis and GLP-1/GIP Medicines
Both Ozempic® and Tirzepatide carry a warning about pancreatitis. This is because a small number of cases were reported in people taking drugs that act on the GLP-1 receptor. In early clinical trials, some patients developed pancreatitis, although it is difficult to know if the medicine directly caused it or if other health factors played a role.
Risk factors for pancreatitis include:
- Gallstones blocking the pancreas duct.
- High alcohol use.
- Very high triglycerides (a type of fat in the blood).
- Previous history of pancreatitis.
For patients with these risk factors, doctors are especially careful before prescribing Ozempic® or Tirzepatide.
What the Studies Show
In large trials of Ozempic®, pancreatitis was reported rarely, affecting less than 1% of participants. Tirzepatide trials showed similarly low rates. Most studies found that the risk was not higher than in people taking other diabetes medicines. Still, because pancreatitis can be very serious, the FDA requires a warning.
If a patient develops symptoms of pancreatitis while on these medicines, doctors usually stop the drug right away. Restarting is not recommended because the condition could return.
Gallbladder Risks: Gallstones and Cholecystitis
The gallbladder is a small organ under the liver that stores bile, a fluid that helps digest fats. One of the known risks with both Ozempic® and Tirzepatide is gallbladder disease, especially gallstones.
Gallstones are hard deposits that can form inside the gallbladder. They can block the ducts and cause severe pain. Symptoms of gallbladder problems include:
- Sharp pain in the upper right belly, sometimes spreading to the shoulder or back.
- Nausea and vomiting.
- Fever or chills (if infection is present).
- Yellowing of the skin or eyes (jaundice) if the bile duct is blocked.
When gallstones lead to inflammation of the gallbladder, it is called cholecystitis. This condition can require urgent medical care, and sometimes surgery to remove the gallbladder.
Why Gallbladder Problems Can Happen
Researchers believe gallbladder issues may be linked to how these medicines slow digestion and promote weight loss. When weight is lost quickly, the liver releases more cholesterol into bile, which can form stones. At the same time, slower emptying of the gallbladder may increase the chance that stones will form.
This means that people who lose weight very fast on Ozempic® or Tirzepatide may face a slightly higher chance of gallstones compared to people losing weight more slowly.
What the Evidence Shows
In clinical studies, gallbladder problems such as gallstones or cholecystitis occurred in a small percentage of patients. For example:
- With Ozempic®, gallbladder disease was reported in fewer than 2% of participants.
- With Tirzepatide, similar low rates were seen, but slightly higher in groups that lost the most weight.
Doctors note that gallbladder disease can also occur in people losing weight by diet and exercise alone, so it is not unique to these medications.
FDA Warnings and Monitoring
Because of these risks, the FDA requires warnings in the prescribing information for both drugs. Patients are told to watch for stomach pain, especially if it is sudden, severe, or linked to nausea or fever.
Healthcare providers may:
- Ask about a history of gallstones or pancreatitis before prescribing.
- Monitor symptoms during follow-up visits.
- Order blood tests or imaging if problems are suspected.
If pancreatitis is confirmed, the medicine must be stopped permanently. If gallbladder disease is found, treatment may include stopping the drug, surgery, or other medical approaches.
What Patients Should Know
- Pancreatitis and gallbladder problems are rare, but serious.
- Anyone with sudden and severe abdominal pain while on Ozempic® or Tirzepatide should contact a healthcare provider right away.
- Patients with a history of pancreatitis usually should not take these medications.
- People at risk for gallstones should discuss this with their doctor, especially if they expect significant weight loss.
Both Ozempic® and Tirzepatide carry low but important risks of pancreatitis and gallbladder disease. The absolute number of cases is small, but because the conditions can be severe, careful monitoring is essential. Understanding the symptoms and seeking medical help quickly can make treatment safer and more effective. For patients, the key is not fear, but awareness and communication with their healthcare team.
Cardiovascular and Kidney Side Effects
When people start new medications such as Ozempic® (semaglutide) or Tirzepatide (Mounjaro®/Zepbound®), one of the big questions is how these drugs affect the heart and kidneys. These organs are especially important for people living with type 2 diabetes or obesity, since both conditions already raise the risk for heart disease and kidney damage. Let’s look carefully at what research shows about these side effects.
Effects on Blood Pressure
Both Ozempic® and Tirzepatide often lead to weight loss. Losing weight can naturally lower blood pressure. In addition, these drugs may have direct effects on blood vessels that help reduce blood pressure further.
- Ozempic®: In clinical trials, people taking semaglutide often saw a drop of around 3 to 5 mmHg in systolic blood pressure (the top number) compared with people taking placebo. This change is modest but meaningful, especially for patients who already have high blood pressure.
- Tirzepatide: Studies show that people taking Tirzepatide may see an even larger drop in blood pressure, sometimes 5 to 7 mmHg or more. This effect may be related to stronger weight loss and the drug’s action on both GLP-1 and GIP receptors.
While lower blood pressure is usually a good thing, it can sometimes lead to dizziness, especially when standing up quickly. This is more likely for patients already on blood pressure medications. Healthcare providers often monitor blood pressure closely during treatment and may adjust other medications if needed.
Effects on Heart Rate
Both Ozempic® and Tirzepatide may cause a small increase in resting heart rate. For most people, the increase is mild, usually around 2 to 4 beats per minute.
- This change is not usually dangerous for healthy individuals.
- However, in people with certain heart rhythm problems, even small increases in heart rate may raise concerns.
Because of this, doctors often ask patients about symptoms such as palpitations (feeling like the heart is racing or skipping beats). If these occur, a heart check-up may be needed.
Cardiovascular Outcomes
The FDA requires special studies called cardiovascular outcome trials for diabetes drugs, to ensure they do not increase the risk of major heart events such as heart attack or stroke.
- Ozempic® (Semaglutide): The SUSTAIN-6 trial tested semaglutide in people with type 2 diabetes who were at high risk for heart disease. Results showed a significant reduction in the risk of heart attack, stroke, and cardiovascular death compared with placebo. Because of this, Ozempic® is considered heart-protective in people with diabetes.
- Tirzepatide: Cardiovascular outcome trials are ongoing. Early data suggest that Tirzepatide does not raise cardiovascular risk. In fact, because it leads to greater weight loss and improvements in blood sugar and cholesterol, many researchers expect it to also show heart-protective benefits. Final results from large trials will give clearer answers.
For now, evidence suggests that both drugs are safe for the heart, and semaglutide already has proven benefits.
Effects on Kidney Function
The kidneys play a key role in filtering blood, balancing fluids, and controlling blood pressure. Diabetes and obesity often strain the kidneys, sometimes leading to chronic kidney disease (CKD). Because of this, it is important to know how these drugs affect kidney health.
- Ozempic®: Research shows semaglutide may help protect the kidneys. In studies, people taking Ozempic® had slower progression of kidney disease compared with placebo. This is thought to be due to improved blood sugar control, lower blood pressure, and direct protective effects on kidney tissue.
- Tirzepatide: Early trial results suggest Tirzepatide may also protect the kidneys, with fewer patients developing kidney complications compared with placebo. More detailed kidney outcome trials are still ongoing.
Risks of Dehydration and Acute Kidney Injury
While both drugs may protect kidneys long-term, they also carry short-term risks linked to their gastrointestinal side effects.
- Vomiting and diarrhea can cause fluid loss.
- If fluid loss is severe, blood pressure may drop and kidney function may worsen.
- This can lead to acute kidney injury (AKI), a sudden decline in kidney function.
These cases are uncommon but have been reported, especially in patients who already have kidney disease. To reduce this risk, doctors often recommend:
- Drinking enough fluids, especially when experiencing nausea, vomiting, or diarrhea.
- Reporting any signs of dehydration, such as dizziness, dry mouth, or reduced urination.
- Regular blood tests to monitor kidney function in higher-risk patients.
For most patients, Ozempic® and Tirzepatide have positive effects on the heart and kidneys. Still, careful monitoring is important. Patients should work with their healthcare providers to track blood pressure, heart health, and kidney function. Staying hydrated and reporting unusual symptoms early are key steps in staying safe while taking these medicines.
Rare but Serious Risks
While most people who take Ozempic® (semaglutide) or Tirzepatide (Mounjaro® / Zepbound®) mainly deal with stomach-related side effects like nausea, there are also rare but more serious risks that patients should understand. These side effects do not happen often, but they are important because of their possible severity. Doctors usually review these risks carefully before prescribing these medicines.
Thyroid C-Cell Tumors (Black Box Warning)
Both Ozempic® and Tirzepatide come with what is called a black box warning from the U.S. Food and Drug Administration (FDA). This is the most serious type of warning placed on prescription drugs.
The warning is about a possible risk of thyroid C-cell tumors, including a rare type of thyroid cancer called medullary thyroid carcinoma (MTC).
- What studies show: In animal studies, both semaglutide (the active ingredient in Ozempic®) and Tirzepatide were linked to thyroid C-cell tumors. These findings came from rodent studies.
- Human data: So far, no clear evidence shows that these drugs cause thyroid cancer in humans. Still, because of the animal data, the FDA requires this strong warning.
- Who should avoid these drugs:
- People with a personal or family history of MTC.
- People with a rare condition called Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).
- People with a personal or family history of MTC.
Doctors usually ask about family history of thyroid cancer before starting these medications. Patients are also advised to report symptoms like a lump in the neck, hoarseness, trouble swallowing, or shortness of breath.
Allergic or Hypersensitivity Reactions
Another serious but rare risk is allergic reactions. Most reactions are mild, like itching or a skin rash, but in very rare cases, severe reactions can happen.
- Mild reactions may include redness or swelling at the injection site.
- Severe reactions can include anaphylaxis, which is a medical emergency. Symptoms may include difficulty breathing, swelling of the face or throat, dizziness, and a fast heartbeat.
While very uncommon, patients should know to seek emergency medical help if they ever experience these symptoms after an injection. Doctors may also instruct patients to avoid future doses if a severe allergic reaction happens.
Emerging Signals from Post-Marketing Reports
When a new drug is first approved, much of the safety data comes from clinical trials, which involve thousands of patients. But once the drug is used by millions of people in the real world, new, rare risks can sometimes appear. This is why both Ozempic® and Tirzepatide are still monitored closely through what is called post-marketing surveillance.
- Pancreatitis reports: Although covered in more detail in another section, cases of pancreatitis (inflammation of the pancreas) have been reported in people using both medicines. This condition can be very painful and, if untreated, may become life-threatening.
- Kidney issues from dehydration: Severe vomiting or diarrhea can sometimes lead to dehydration and kidney injury. While this is rare, it is a recognized risk in post-marketing data.
- Unusual symptoms being tracked: Regulators are watching for reports of hair loss, mood changes, or gastrointestinal blockages, though these have not been proven as direct side effects yet.
Doctors and pharmacists often remind patients that just because a side effect is reported does not mean it is proven to be caused by the medicine. Still, collecting these reports helps experts see possible safety patterns over time.
Putting Rare Risks in Context
It is important to keep these risks in perspective:
- Most people never experience them. The majority of patients using Ozempic® or Tirzepatide only report stomach-related side effects.
- Serious side effects are uncommon. But because the possible consequences can be life-threatening, healthcare providers discuss them before starting therapy.
- Monitoring is key. Regular check-ups, lab work if needed, and reporting unusual symptoms can help catch rare problems early.
Patient Safety Tips
- Tell your doctor if you or a family member has had thyroid cancer, especially medullary thyroid carcinoma.
- Report any neck swelling, trouble swallowing, or persistent hoarseness.
- Watch for signs of an allergic reaction, especially after the first few doses.
- Stay hydrated, especially if you experience vomiting or diarrhea.
- Follow up with your healthcare team if you notice any new or unusual symptoms.
While rare, the most serious risks of Ozempic® and Tirzepatide include the potential for thyroid tumors, severe allergic reactions, pancreatitis, and kidney complications from dehydration. These risks are uncommon but important to understand. Patients should work closely with their healthcare team to stay safe while using these medicines.
Long-Term Tolerability: What We Know So Far
When patients start Ozempic® (semaglutide) or Tirzepatide (sold under the brand names Mounjaro® and Zepbound®), one of the biggest questions they have is: Can I stay on this medication long-term without too many problems? To answer this, researchers have studied these drugs for one year or longer in clinical trials, and doctors have reported what they see in real-world practice.
Clinical Trial Data Over One to Two Years
Ozempic® has been studied in multiple long-term trials, some lasting up to two years. These trials looked at people with type 2 diabetes as well as people using the medication for weight management. In these studies, the side effects were mostly the same as those seen early on, such as nausea, vomiting, diarrhea, and constipation. Importantly, these effects usually happened in the first few months of treatment and became less frequent or less severe over time.
Tirzepatide is newer, but there are already several trials lasting up to 72 weeks (about a year and four months). These trials show a similar pattern: side effects are most common in the early months, especially during dose increases, but many people adapt as their bodies get used to the medication. The most common reason people stopped taking Tirzepatide was gastrointestinal discomfort, but this was also true for people on Ozempic®.
In both drugs, the percentage of people who had to stop due to side effects was relatively low, usually under 10% in longer studies. This suggests that most people who can handle the early months of treatment are able to stay on the medication long-term.
Real-World Adherence and Discontinuation
While clinical trials give us valuable information, real-world experience sometimes looks a little different. In real life, patients may have other health conditions, take other medications, or face challenges that make it harder to continue.
Reports from real-world use show that some people do stop Ozempic® or Tirzepatide because of ongoing nausea, constipation, or other discomforts. For others, the cost or availability of the medication can play a role in stopping. Still, many patients continue these treatments for a year or longer, especially when they see meaningful weight loss or blood sugar improvements.
Doctors often stress the importance of slow dose increases and careful monitoring. This helps patients tolerate the medication better. Those who adjust gradually are more likely to remain on therapy long-term.
Patterns of Long-Term Side Effects
Over time, the side effect profile does not usually change. For most patients, if they have not experienced serious problems like pancreatitis, gallbladder issues, or severe allergic reactions in the first months, these events are less likely to suddenly appear later.
That said, both Ozempic® and Tirzepatide carry warnings about rare but serious risks such as thyroid tumors, pancreatitis, and gallbladder disease. These risks do not appear to increase dramatically with longer use, but ongoing monitoring is important. Doctors often remind patients to report new abdominal pain, changes in digestion, or lumps in the neck.
Another aspect of long-term tolerability is how well people accept living with the side effects that may remain. Some individuals report mild nausea or irregular bowel habits that never fully go away. While not dangerous, these issues can affect quality of life. The decision to continue often depends on whether the benefits, such as weight loss and improved blood sugar control, outweigh the discomfort.
Ongoing Research
Because Tirzepatide is newer, researchers are still learning about its long-term safety and tolerability. Several large trials are underway to study outcomes over several years, especially in people with heart disease or kidney disease. For Ozempic®, there is already more established evidence, including cardiovascular outcome trials lasting more than two years, which found the medication to be generally safe.
It is likely that future studies will continue to compare Ozempic® and Tirzepatide directly, not just for how much weight patients lose or how much blood sugar improves, but also for how well patients can stay on them without major side effects. These studies will help answer questions about tolerability beyond the two-year mark.
The evidence so far suggests that both Ozempic® and Tirzepatide can be tolerated for the long term, especially if patients manage the first few months carefully. Side effects usually appear early and either fade or become easier to manage with time. Most people who stop the medication do so within the first months, while those who continue often stay on it for a year or longer.
Still, each person’s experience is unique. Long-term tolerability depends on individual health conditions, how the medication is dosed, and how well side effects are managed. Regular check-ins with a healthcare provider are essential. This ensures that any new issues are caught early and that the benefits of therapy continue to outweigh the risks.
Drug Interactions and Safety with Other Conditions
When people take Ozempic® (semaglutide) or Tirzepatide (sold under the brand names Mounjaro® and Zepbound®), they often already use other medicines for diabetes, high blood pressure, high cholesterol, or other health problems. Because of this, it is important to know how these drugs may interact with other medicines, and how safe they are for people who also have other medical conditions.
How These Medicines Affect the Stomach and Absorption of Other Drugs
Both Ozempic® and Tirzepatide slow down the emptying of the stomach. This means food and medicines taken by mouth move more slowly from the stomach into the intestines. While this effect helps control blood sugar and reduce appetite, it can also change how other pills are absorbed.
For most medicines, this slower absorption does not cause major problems. However, for drugs that must be absorbed quickly to work well, such as some antibiotics, pain relievers, or heart medications, there could be concerns. For example:
- Oral contraceptives (birth control pills): Slower absorption may slightly change how well they work, especially in the first month after starting Ozempic® or Tirzepatide. Doctors may suggest using backup birth control during dose changes.
- Thyroid medication (like levothyroxine): Timing may need adjustment to avoid reduced absorption.
- Blood thinners (like warfarin): Any change in absorption could affect blood clotting control, so regular blood checks may be needed.
Because of these possible interactions, doctors usually ask patients to tell them about every medication, vitamin, or supplement they take. Sometimes timing doses at different parts of the day can reduce risks.
Caution in People with Diabetic Retinopathy
Diabetic retinopathy is an eye disease caused by diabetes. It can lead to vision loss if not managed carefully. Studies have shown that Ozempic® may sometimes make retinopathy worse, especially if blood sugar drops very quickly after starting treatment.
Tirzepatide has not yet shown the same strong link, but research is still ongoing. Both drugs lower blood sugar effectively, and a sudden improvement can stress the small blood vessels in the eye. For this reason, people with advanced diabetic eye disease should have regular eye exams before and during treatment.
Considerations for Kidney Disease
Both Ozempic® and Tirzepatide are not cleared mainly through the kidneys, so the drugs themselves are usually safe for people with mild to moderate kidney disease. However, severe nausea, vomiting, or diarrhea—common side effects—can lead to dehydration. Dehydration can cause kidney injury, especially in people whose kidneys are already weak.
Patients with kidney disease are usually told to drink enough fluids and to contact their doctor if they cannot keep fluids down for more than a day. Doctors may also check kidney function more often during treatment.
Gastrointestinal Disorders
Since both medicines act on the stomach and intestines, they may not be a good choice for people who already have serious gastrointestinal problems. This includes conditions such as:
- Gastroparesis (delayed stomach emptying), which can be made worse.
- Severe reflux or GERD, which may flare up due to slower digestion.
- Inflammatory bowel disease (like Crohn’s or ulcerative colitis): Research is still limited, but caution is often advised.
Doctors may choose other treatments if a person already struggles with these problems.
Comparing in Complex Medical Cases
- Heart disease: Both drugs tend to lower blood pressure and improve cholesterol, which is helpful. Some patients may notice a slight increase in heart rate, which doctors monitor.
- Liver disease: These drugs can generally be used safely, but people with severe liver disease should be followed closely.
- Older adults: Both Ozempic® and Tirzepatide can cause stronger nausea in people over 65. Dosing may need to be slower and side effects carefully monitored.
When doctors compare Ozempic® and Tirzepatide in patients with other medical conditions, the choice often depends on the person’s history and tolerance. For example, if a patient already has eye disease, the doctor may prefer Tirzepatide. If a patient has frequent stomach problems, they may prefer Ozempic® if it is better tolerated.
Comparing Side Effects by Dose Escalation
When starting medications like Ozempic® (semaglutide) and Tirzepatide (brand names Mounjaro® and Zepbound®), doctors rarely give the full dose right away. Instead, patients begin at a lower dose and increase slowly over several weeks or months. This process is called dose escalation or dose titration. The goal is to allow the body to adjust to the medication, lower the chance of side effects, and improve long-term tolerability.
Understanding how dose escalation affects side effects is important for anyone considering or already taking these medicines. Even though both drugs are used for weight management and type 2 diabetes, the way doses are increased — and the side effects patients experience during this period — can be different.
Stepwise Dosing for Ozempic®
Ozempic® comes in several pen injector strengths. The usual starting dose is 0.25 mg once a week. Patients stay on this dose for four weeks. This is not considered a “therapeutic” dose for blood sugar control or weight loss, but it helps the body get used to the drug.
After four weeks, the dose is usually increased to 0.5 mg weekly. If blood sugar or weight control is not enough, the doctor may increase the dose to 1 mg weekly. In some cases, a maximum dose of 2 mg weekly may be prescribed.
Because the increases happen step by step, patients may notice fewer or milder side effects compared with starting on a high dose right away. Still, many people experience nausea, bloating, or diarrhea during the first weeks of each increase.
Stepwise Dosing for Tirzepatide (Mounjaro®/Zepbound®)
Tirzepatide also follows a gradual dose increase. The usual starting dose is 2.5 mg once a week. Like Ozempic®, this starting dose is not meant for full treatment but to help the body adapt.
After four weeks, the dose typically increases to 5 mg weekly. Depending on how well the drug is tolerated and how much blood sugar or weight loss benefit is needed, the dose may continue to rise in 2.5 mg steps every four weeks. The highest dose is 15 mg weekly.
Because Tirzepatide has more possible dose levels, it gives doctors flexibility. However, the larger jumps in dosing can sometimes cause stronger gastrointestinal side effects during titration, especially nausea or diarrhea.
How Titration Speed Affects Side Effects
Both medications affect digestion by slowing the emptying of the stomach. This delay helps people feel full sooner and eat less, but it is also the main reason for side effects like:
- Nausea
- Vomiting
- Constipation
- Diarrhea
- Bloating or stomach discomfort
When the dose increases too quickly, these side effects are more likely to occur. For example:
- If a patient on Ozempic® moves from 0.25 mg to 1 mg in only a few weeks, the body may not adjust well, leading to more severe nausea.
- If a patient on Tirzepatide escalates to 10 mg or higher without enough time at the lower doses, the risk of vomiting and diarrhea increases.
That is why doctors usually recommend waiting several weeks before each increase. This slower titration allows the gut and brain to adapt to the medicine’s effects.
Why Some Patients Tolerate One Medication Better
Although both Ozempic® and Tirzepatide affect digestion, patients often report that they tolerate one better than the other. There are a few possible reasons:
- Different mechanisms of action – Ozempic® only activates the GLP-1 receptor, while Tirzepatide activates both the GIP and GLP-1 receptors. This double action may make Tirzepatide more effective for weight loss, but it could also explain stronger side effects at higher doses.
- More dosing options with Tirzepatide – Because it has more steps (2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg), doctors can tailor dosing more closely. This flexibility may help patients who need slower or more gradual increases.
- Individual differences – Some people naturally have more sensitive digestive systems. Their response to medication may vary, regardless of the drug chosen.
Managing Side Effects During Dose Escalation
Healthcare providers often give advice to help manage side effects, especially during the first few weeks after a dose increase. Common recommendations include:
- Eating smaller meals to reduce nausea.
- Avoiding high-fat or greasy foods, which can worsen stomach upset.
- Staying hydrated to reduce constipation and prevent dehydration from diarrhea.
- Using over-the-counter remedies, like anti-nausea or anti-constipation medicines, if approved by a doctor.
If side effects are severe, doctors may pause the escalation and keep the patient at the current dose longer before trying the next step. In some cases, reducing the dose or stopping the drug may be necessary.
Conclusion
Ozempic® (semaglutide) and Tirzepatide (sold under brand names such as Mounjaro® and Zepbound®) are powerful medicines that help with type 2 diabetes and weight management. Both belong to a group of medicines that mimic natural hormones in the body to control blood sugar and support weight loss. While they are very effective, they also share many side effects that patients should understand before starting treatment. Knowing what to expect can help people prepare, manage discomfort, and work closely with their healthcare providers to stay safe.
One of the most important similarities between these two medicines is the way they affect the digestive system. Nausea, vomiting, diarrhea, constipation, and stomach pain are very common. This happens because the drugs slow down how quickly food moves through the stomach. For many patients, these symptoms are temporary and get better after a few weeks. However, some people find the effects too uncomfortable and may stop taking the medicine. Studies show that the chance of nausea and other stomach problems is higher at the beginning of treatment or when the dose is increased too quickly. Healthcare providers usually recommend a step-by-step increase in dose to give the body time to adjust.
Another key similarity is the black box warning about the risk of thyroid C-cell tumors. This warning is based on studies in animals. So far, these tumors have not been proven to occur in humans from taking these drugs, but the risk cannot be ruled out. Because of this, neither Ozempic® nor Tirzepatide should be used in people with a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia syndrome type 2. Patients should also report any unusual neck swelling, hoarseness, or difficulty swallowing.
There are also differences between the two medicines. Tirzepatide works on two hormone pathways, GLP-1 and GIP, while Ozempic® works only on GLP-1. Some studies suggest that this dual action may lead to greater weight loss and stronger improvements in blood sugar control. However, this can also mean that gastrointestinal side effects feel more intense for certain patients. Tirzepatide users sometimes lose weight faster, and that rapid weight loss itself may increase risks like gallstones or gallbladder inflammation. Ozempic® patients may also develop gallbladder issues, but the rates can vary. The balance between faster results and stronger side effects is an important part of deciding which medicine might be right.
Both drugs can affect blood sugar in ways that may cause problems if combined with other diabetes medicines. On their own, they do not usually cause dangerous low blood sugar (hypoglycemia). But when taken with insulin or sulfonylureas, the chance of hypoglycemia rises. Careful monitoring and dose adjustments are needed in these cases. Patients who are not diabetic but use these drugs for weight loss should also be aware of signs of low blood sugar, such as dizziness, sweating, or confusion.
Other rare but serious risks include pancreatitis, severe allergic reactions, and kidney problems. Pancreatitis shows up as sudden and strong stomach pain that does not go away. Allergic reactions may include rash, swelling, or trouble breathing. Kidney problems may happen when severe vomiting or diarrhea causes dehydration. Because these side effects can be serious, patients need to know when to stop the drug and get medical help right away.
In terms of long-term use, both medicines have shown safety over one to two years in large studies, but research is still ongoing. Doctors are watching closely for any new risks that may appear with longer use. So far, many patients continue treatment without major problems, though some stop due to side effects. Real-world experience will continue to add important information over time.
Finally, dose schedules matter a lot. Ozempic® and Tirzepatide are both started at low doses and slowly increased. This step-up approach is meant to reduce side effects. If patients rush dose increases or skip steps, they are more likely to feel sick and may need to stop. Following the recommended plan can make treatment easier to tolerate and safer overall.
In conclusion, Ozempic® and Tirzepatide have many shared side effects, especially with the stomach and digestive system, and both carry serious warnings that patients should not ignore. At the same time, Tirzepatide’s dual action may give stronger benefits but sometimes leads to stronger discomfort. Choosing between these medicines is not a matter of one being “better” than the other, but of which one fits best with a patient’s health history, goals, and ability to manage side effects. Every patient should talk with a healthcare provider to weigh the benefits against the risks, and to get advice on how to handle side effects if they appear. Understanding the possible problems helps patients make informed decisions, stay safe during treatment, and get the most out of these important new medicines.
Research Citations
Frías, J. P., Davies, M. J., Rosenstock, J., Pérez Manghi, F. C., Fernández Landó, L., Bergman, B. K., Liu, B., Cui, X., & Brown, K. (2021). Tirzepatide versus semaglutide once weekly in patients with type 2 diabetes. The New England Journal of Medicine, 385(6), 503–515.
Aronne, L. J., Bade Horn, D., le Roux, C. W., Ho, W., Falcon, B. L., Gomez Valderas, E., Das, S., Lee, C. J., Glass, L. C., Senyucel, C., Dunn, J. P., & SURMOUNT-5 Investigators. (2025). Tirzepatide as compared with semaglutide for the treatment of obesity. The New England Journal of Medicine, 393(1), 26–36.
Rodriguez, P. J., Goodwin Cartwright, B. M., Gratzl, S., Brar, A., Baker, K., Gluckman, T., & Stucky, B. (2024). Semaglutide vs tirzepatide for weight loss in adults with overweight or obesity. JAMA Internal Medicine, 184(9), 1120–1130.
Karagiannis, T., Malandris, K., Avgerinos, I., Stamati, A., Kakotrichi, P., Liakos, A., Vasilakou, D., Kakaletsis, N., Tsapas, A., & Bekiari, E. (2024). Subcutaneously administered tirzepatide vs semaglutide for adults with type 2 diabetes: A systematic review and network meta-analysis of randomised controlled trials. Diabetologia, 67(7), 1206–1222.
Ding, Y., Shi, Y., Guan, R., Yan, S., Liu, H., Wang, Z., Li, J., Wang, T., Cai, W., & Ma, G. (2024). Evaluation and comparison of efficacy and safety of tirzepatide and semaglutide in type 2 diabetes: A Bayesian network meta-analysis. Pharmacological Research, 199, 107031.
Ciudin, A., Johansson, E., Zimner-Rapuch, S., Dimitriadis, G. K., Bertrand, M., Curteis, T., Clark, L. J., Fan, L., Sapin, H., & Bergmann, J.-F. (2025). Indirect comparative efficacy and safety of tirzepatide 10 and 15 mg versus semaglutide 2.4 mg for the management of obesity and overweight in patients with type 2 diabetes. Diabetes, Obesity and Metabolism, 27(9), 4709–4719.
Hankosky, E. R., He, X., Malik, R., Fraseur Brumm, J., Wang, F., Niemeyer, A., Zhang, X.-M., & Garvey, W. T. (2025). Tirzepatide 10 and 15 mg versus semaglutide 2.4 mg in people with obesity or overweight with type 2 diabetes: An indirect treatment comparison. Diabetes, Obesity and Metabolism, 27(7), 3757–3765.
Singh, A., Singh, A. K., Singh, R., & Misra, A. (2025). Comparative efficacy and safety of semaglutide 2.4 mg and tirzepatide 5–15 mg in obesity with or without type 2 diabetes: A systematic review of Phase 3 clinical trials. Diabetes & Metabolic Syndrome: Clinical Research & Reviews, 19(3), 103212.
Xie, Z., Zheng, G., Liang, Z., Li, M., Deng, W., & Cao, W. (2025). Comparative safety of GLP-1/GIP co-agonists versus GLP-1 receptor agonists for weight loss in patients with obesity or overweight: A systematic review. [Journal in PMC].
Wen, J., Zhao, X., Liu, Y., & Li, H. (2025). Tirzepatide versus semaglutide on weight loss in type 2 diabetes: A systematic review with adverse event comparison. [Journal indexed in PubMed].
Questions and Answers: Ozempic vs Tirzepatide Side Effects
Both cause nausea, vomiting, diarrhea, constipation, and abdominal pain. These GI symptoms are usually mild to moderate and occur more often when starting or increasing the dose.
Studies suggest semaglutide (Ozempic) may cause slightly more nausea compared to tirzepatide, though both have this as the most frequent side effect.
Weight loss is a therapeutic effect, not a side effect, but it’s partly due to appetite suppression and delayed stomach emptying, which can feel like side effects (early fullness, reduced appetite).
Yes. Both carry a warning for possible pancreatitis (inflammation of the pancreas). Patients with severe abdominal pain should seek medical help immediately.
Yes. Both drugs have been linked to gallstones and gallbladder inflammation, partly due to rapid weight loss.
Both carry a boxed warning for possible risk of medullary thyroid carcinoma (MTC) based on rodent studies. They should be avoided in people with a personal/family history of MTC or MEN2 syndrome.
On their own, they rarely cause hypoglycemia. However, when combined with insulin or sulfonylureas, the risk increases.
Constipation can occur with both, but tirzepatide seems to cause it slightly more often than semaglutide in some trials.
Both may cause a small increase in heart rate. Semaglutide (Ozempic) has proven cardiovascular benefits in people with type 2 diabetes and heart disease; tirzepatide’s cardiovascular outcome trial is ongoing.
Yes. If nausea, vomiting, or other side effects are severe or persistent, the dose may need to be reduced or the medication discontinued under a doctor’s guidance.
