What you’ll learn:
- Whether you take Zepbound® or Mounjaro®, your dose of tirzepatide will be increased gradually to maximize results while minimizing side effects.
- Common side effects of tirzepatide medications include nausea, diarrhea, and constipation, which generally subside over time as your body adjusts to the medication.
- Serious but rare interactions that require medical attention can occur.
Tirzepatide is the active ingredient in two weekly injectable medications—Zepbound® and Mounjaro®—used to help manage weight or type 2 diabetes. It works by mimicking two natural hormones that help regulate your appetite, digestion, and blood sugar. As your body adjusts to those changes, it’s common to experience some side effects, especially early on.
The most frequent side effects are mild to moderate digestive issues, like nausea, stomach pain, or changes in bowel habits. These tend to occur when you first start the medication or when your dose increases, and usually ease up over time as your body gets used to it. Some people also report feeling a little more tired than usual, getting headaches, or noticing some redness or irritation at the injection site.
Most of these side effects can be managed with hydration, small food adjustments, and keeping an open line of communication with your provider about your dose. But there are a few rare but serious side effects to be aware of, and it’s important to know when something might need urgent attention.
Understanding what to expect—both the normal stuff and the red flags—can help you feel more confident going into treatment. We’ll break down what to watch for and share simple strategies to help you feel your best while getting the full benefits of tirzepatide.
How tirzepatide affects your body
Tirzepatide mimics the effects of two naturally occurring gut hormones: GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide). These hormones are part of a group called incretins, which help regulate blood sugar levels and appetite in response to eating. Let’s take a look at what happens when you take Zepbound® or Mounjaro®.
- In the digestive system, tirzepatide slows the rate at which food leaves the stomach—a process known as gastric emptying. This helps control blood sugar spikes after meals and keeps you feeling full longer, further supporting weight loss and appetite control.
- In the brain, tirzepatide works on appetite-regulating centers to reduce hunger and cravings, increase feelings of fullness, and help you feel satisfied with smaller meals. This helps people eat less without feeling deprived.
- In the pancreas, tirzepatide improves the body’s response to food by boosting insulin secretion only when blood sugar is elevated. It also reduces glucagon, a hormone that raises blood sugar. Together, these actions help lower blood sugar levels and improve insulin sensitivity, making tirzepatide effective for people with type 2 diabetes as well as those using it for weight management.
Because it mimics both GLP-1 and GIP, tirzepatide may offer benefits beyond medications like Ozempic® and Wegovy®, which only target GLP-1. GIP activation may enhance fat burning, improve insulin action even more, and amplify weight loss results in some individuals.
When are side effects most likely?
Side effects with Mounjaro® or Zepbound® are most common when starting the medication or increasing your dose. Both begin at the lowest dose, 2.5 mg, once weekly for the first four weeks. If you’re tolerating the starting dose well, then you’ll increase to 5 mg. This dose escalation continues as needed through 7.5 mg, 10 mg, 12.5 mg, and up to a maximum of 15 mg. This gradual step-up schedule or titration helps your body adjust and is specifically designed to minimize common side effects like nausea, fatigue, or stomach upset. The approach improves tolerability while still supporting weight loss or blood sugar control, with the flexibility to pause at lower doses if you’re responding well.
Most side effects are mild and temporary, especially in the first few weeks of starting with a new dose as your body adjusts. Let’s take a look at what most people experience:
Common side effects and symptoms
Digestive issues are among the most common side effects reported with tirzepatide, especially when starting treatment or increasing your dose. Here’s a closer look at the most frequently reported gastrointestinal symptoms with a few commonly used doses, along with tips that can help manage them. The data below is based on clinical trial findings reported in the prescribing information.
| Symptom | Tirzepatide 5 mg | Tirzepatide 10 mg | Tirzepatide 15 mg | What can help |
|---|---|---|---|---|
| Nausea | 25% | 29% | 28% | Eating small, low-fat meals and avoiding greasy or spicy foods can reduce nausea. |
| Diarrhea | 19% | 21% | 23% | Staying hydrated and choosing low-fiber, easy-to-digest foods may help. |
| Vomiting | 8% | 11% | 13% | Clear fluids and bland foods like toast or crackers are frequently recommended to soothe an upset stomach. |
| Constipation | 17% | 14% | 11% | Doctors often advise increasing fiber slowly, drinking more water, and adding gentle movement. |
| Abdominal pain | 9% | 9% | 10% | Sticking with clear liquids and briefly pausing solid foods can help ease abdominal pain. |
| Indigestion | 9% | 9% | 10% | Eating slowly and avoiding lying down right after meals can help. |
These symptoms can be uncomfortable, but they’re usually manageable. If they aren’t, you can choose to lower your dose in coordination with your healthcare provider.
Other symptoms
While digestive symptoms tend to get the most attention, tirzepatide may also cause other effects on energy levels, mood, and more. These side effects are also usually manageable and often improve with time or dose adjustment.
| Symptom | Tirzepatide 5 mg | Tirzepatide 10 mg | Tirzepatide 15 mg | What can help |
|---|---|---|---|---|
| Dizziness | 4% | 5% | 4% | Drink enough water and avoid standing up too quickly to reduce the risk of feeling lightheaded. |
| Fatigue | 5% | 6% | 7% | Make sure to get enough sleep, maintain a balanced diet, and include light physical activity to help improve energy levels. |
| Dry mouth/throat* | 1% (combined data) | — | — | Sip water regularly. |
| Dysgeusia (altered taste)* | 0.4% (combined data) | — | — | This side effect is typically mild and short-lived, but you should talk to your healthcare provider if it continues or affects your appetite. |
| Dysesthesia (tingling, burning) | 0.2% | 0.2% | 0.4% | If you experience unusual tingling or burning sensations, monitor their progression and inform your provider for further evaluation. |
| Heart palpitations or racing heart | 4.6–7% | 5.9–9.3% | 10–23% | These episodes are usually temporary, but if you feel heart palpitations or your pulse seems unusually fast, check in with your healthcare provider. |
| Hair loss | 5% | 4% | 5% | Hair shedding may occur with weight loss and usually resolves over time. Speak with your provider about supportive options like biotin or scalp care. |
*Dry mouth and altered taste were reported at low rates across all doses, based on combined data from multiple studies. Specific rates for each dose weren’t listed.
Additional considerations
- Mood changes: While not seen in trials, broader GLP-1 class data include rare psychiatric events, making up just 1.2% of all reported side effects.
If you or someone you know is struggling with thoughts of self-harm or suicide, help is available. Call or text the 988 Suicide & Crisis Lifeline at 988 for free, confidential support 24/7.
Injection site reactions
Mounjaro® is available as a prefilled pen, while Zebound is available as a prefilled pen and single-dose vials. Whether you use a pen or a vial, you’ll give yourself a weekly injection in the thigh, abdomen, or upper arm. Like many injectable medications, it can cause mild skin reactions at the injection site. While both methods deliver the same medication, differences in injection technique can slightly affect your experience at the injection site.
Single-dose vials require drawing the medication into a syringe, which introduces more steps and may increase the risk of air bubbles or dosing inconsistencies if not handled properly. Pens, by contrast, are generally easier to use and offer more consistent delivery, which may reduce the chance of irritation due to injection error.
These reactions may occur with either pen injectors or traditional vial-and-syringe methods, depending on which format your medication comes in.
Common reactions include:
- Mild pain, redness, or swelling at the injection site
- Itching, lumps, or skin irritation
- Rare cases of bruising or rash, particularly with repeated injections in the same area
These reactions are typically mild and go away on their own within a few days. About 3% to 6% of people using Mounjaro® or Zepbound® will have some sort of reaction.
Tips to prevent or reduce injection discomfort
- Rotate injection sites: Don’t inject into the same spot week after week. Rotate between the thigh, abdomen, and upper arm.
- Clean skin gently: Use an alcohol swab and let the skin dry completely before injecting to reduce stinging.
- Avoid irritated or scarred areas: Only inject into healthy, intact skin.
- Warm the medication slightly: If stored in the fridge, let the pen or vial sit at room temperature for 15–30 minutes before use.
- Use proper technique: For vials, follow your healthcare provider’s guidance on drawing the dose. For pens, follow device instructions carefully.
- Apply light pressure after injection: If needed, use a cotton ball to reduce redness or minor bleeding.
If reactions persist or worsen, or if you notice signs of infection (heat, pus, worsening pain), reach out to your healthcare provider.
Are there side effects of stopping tirzepatide?
Tirzepatide is designed to support long-term weight and blood sugar management. If you stop taking it without a plan in place, your body may respond in ways that can make it harder to maintain your progress. Any changes to your medication—including stopping or pausing treatment—should only be done under the guidance of your healthcare provider.
Here’s what to expect if you pause or discontinue treatment:
- Hunger may return: Tirzepatide works in part by reducing appetite. Once the medication is stopped, it’s common for hunger cues and food cravings to become more noticeable again.
- Some weight regain is likely: Without continued support from the medication, regaining some of the lost weight is possible.
- A gradual taper may help: In some cases, slowly reducing the dose under your provider’s guidance can ease the transition and give your body more time to adjust.
- Healthy habits make a difference: Building consistent routines around movement, nutrition, sleep, and stress management can help preserve your progress after stopping tirzepatide. Having tools for tracking, support, and accountability—like Noom—can also help you stay on course.
Before stopping or adjusting your dose, it’s important to talk with your healthcare provider. They can help you create a plan that supports your long-term goals—whether that includes staying on tirzepatide, transitioning off, or shifting to another approach.
Do females experience different side effects with tirzepatide?
Tirzepatide doesn’t cause side effects that are exclusive to females, but hormone-related changes and the way weight loss affects the body can shape how some symptoms show up or feel. Here are a few things to keep in mind:
- PCOS and menstrual changes: Tirzepatide may help regulate cycles by improving insulin resistance and reducing weight, two key issues in PCOS. Some GLP-1 users report irregular periods or spotting, often due to shifting hormones during weight loss.
- Fertility and contraception: Weight loss can increase the chances of pregnancy by restoring regular ovulation for some people as they lose weight. But tirzepatide isn’t safe during pregnancy or while trying to conceive. If you’re trying to conceive, you should stop taking any medication with tirzepatide two months before.
- Hair loss: Reported hair thinning may worsen PCOS-related alopecia or menopause-related hair changes.
Severe side effects and warnings
While uncommon, tirzepatide (Zepbound® and Mounjaro®) may lead to serious conditions. Contact your healthcare provider or seek immediate medical attention if you experience any of the following:
- Pancreatitis: Be alert for severe stomach pain that may radiate to your back, often with ongoing nausea or vomiting.
- Gallbladder issues: Symptoms include upper abdominal pain, fever, yellowing of the skin or eyes (jaundice), or unusually pale stools.
- Kidney problems: Signs include swelling in the legs or ankles, reduced urination, fatigue, or trouble breathing, especially after prolonged vomiting or dehydration.
- Low blood sugar (hypoglycemia): This is more likely when used with insulin or sulfonylureas for diabetes. Look for shakiness, confusion, sweating, dizziness, blurred vision, or rapid heartbeat.
- Vision changes: Sudden changes in eyesight, especially in people with type 2 diabetes, require immediate medical attention.
- Allergic reactions: Get immediate help for any swelling of the face, lips, tongue, or throat; difficulty breathing; rash; or severe itching.
Boxed warning: thyroid C-cell tumors
Tirzepatide has a boxed warning for the potential risk of thyroid C-cell tumors. This has been observed in animal studies, but its relevance to humans is unknown.
Remember, we’re still learning about the long-term effects of Tirzepatide. If you notice anything out of the ordinary, don’t hesitate to reach out to your healthcare provider. They’re there to help you navigate this journey and ensure you’re staying healthy while taking the medication.
Who shouldn’t take tirzepatide
Tirzepatide isn’t right for everyone, especially if you have certain health conditions that could raise the risk of complications. Here’s when it may not be a safe choice:
- You or a close family member has had medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN 2).
- You’re allergic to tirzepatide or any of its ingredients.
- You’re pregnant, planning to get pregnant, or breastfeeding.
Talk to your doctor if:
- You’ve had pancreatitis.
- You have a serious digestive condition, like gastroparesis, which slows how quickly food moves through your stomach. Tirzepatide could increase nausea, bloating, or discomfort.
For more information, visit the Zepbound® or Mounjaro® safety pages.
Comparing tirzepatide to other GLP-1 medications
All GLP-1 medications can cause digestive side effects like nausea, vomiting, and diarrhea, especially during the first few weeks or as the dose increases. But not all GLP-1s affect people the same way.
Tirzepatide (Zepbound®/Mounjaro®) and dulaglutide (Trulicity®) tend to have lower rates of nausea and constipation compared to semaglutide (Wegovy®/Ozempic®) and liraglutide (Saxenda®/Victoza®).
Here’s how they compare at the maximum dose for each:
| Medication (dose) | Nausea | Vomiting | Diarrhea | Constipation | Indigestion |
|---|---|---|---|---|---|
| Tirzepatide (15 mg) (Zepbound® and Mounjaro®) | 28% | 13% | 23% | 11% | 10% |
| Semaglutide (2.4 mg) (Wegovy®) | 44% | 24% | 30% | 24% | 9% |
| Liraglutide (3 mg) (Saxenda®) | 39% | 15% | 21% | 19% | 9% |
| Dulaglutide (4.5 mg) (Trulicity®) | 16% | 9% | 10% | Not reported | 2% |
Some things to note:
- Tirzepatide vs semaglutide: At the maximum dosage of tirzepatide, lower nausea, vomiting, diarrhea, and constipation rates have been reported compared to the highest dose of semaglutide.
- Liraglutide: At full dose, liraglutide had fewer side effects than semaglutide, but more nausea and vomiting than tirzepatide.
- Dulaglutide had the lowest GI side effect rates overall. Less constipation and abdominal discomfort were also reported.
Understanding the side effects of tirzepatide
Tirzepatide offers a powerful combination of weight loss and blood sugar control by targeting both GLP-1 and GIP receptors—an approach that sets it apart from other medications in its class. While the results can be significant, it’s important to go into treatment with a clear understanding of how your body might respond. Most side effects are manageable with small adjustments to your routine, especially during the early weeks of treatment or dose increases. Knowing what to expect—and how to handle it—can make your experience smoother and more sustainable.
Whether you’re considering tirzepatide for the first time, adjusting your dose, or thinking about long-term use, staying informed is one of the most important tools you have. If you want to know whether a tirzepatide medication like Zepbound or Mounjaro is right for you, see if you qualify for Noom Med. If you do, our clinicians can prescribe medication where needed, and you’ll get access to a program designed to help you lose weight and improve your habits and long-term health.
