The short answerThe most common semaglutide side effects are digestive: nausea, diarrhea, vomiting, constipation, and stomach pain. They are usually mild to moderate, show up most often while the dose is being raised, and ease with time for most people. Rare but serious risks include pancreatitis, gallbladder problems, and dehydration that strains the kidneys, so severe or lasting symptoms always deserve a call to your doctor.
Semaglutide side effects are the first thing many people ask about, and most of them happen in the stomach. This guide walks through what the FDA labels for Wegovy and Ozempic, the two brand-name semaglutide injections, actually report, what helps with nausea and constipation, and which symptoms need medical care. It comes from MeliOra, where board-certified family physician Dr. Melanie Espinet prescribes and monitors every plan for semaglutide weight loss in Lutz and Tampa herself.
Every percentage below is copied as printed from those labels. Dr. Espinet prescribes semaglutide and explains your specific medication at your visit.
Common semaglutide side effects, by the numbers
The Wegovy label pools three placebo-controlled trials in 2,116 adults with obesity or overweight who took semaglutide 2.4 mg once a week for up to 68 weeks. Comparing each side effect with placebo shows what the medication itself adds.
Wegovy 2.4 mg vs placebo (Wegovy label)| Side effect | Wegovy 2.4 mg | Placebo |
|---|
| Nausea | 44% | 16% |
|---|
| Diarrhea | 30% | 16% |
|---|
| Vomiting | 24% | 6% |
|---|
| Constipation | 24% | 11% |
|---|
| Stomach (abdominal) pain | 20% | 10% |
|---|
| Headache | 14% | 10% |
|---|
| Fatigue (includes weakness) | 11% | 5% |
|---|
| Indigestion (dyspepsia) | 9% | 3% |
|---|
| Dizziness | 8% | 4% |
|---|
| Bloating (abdominal distension) | 7% | 5% |
|---|
| Burping (eructation) | 7% | Less than 1% |
|---|
| Low blood sugar, in people with type 2 diabetes | 6% | 2% |
|---|
| Gas (flatulence) | 6% | 4% |
|---|
| Heartburn (gastroesophageal reflux disease) | 5% | 3% |
|---|
Two things stand out. Placebo groups reported plenty of the same symptoms: 16% had nausea with no semaglutide at all, so not every queasy day comes from the medication. And dose matters. The Ozempic label, which covers lower weekly doses used for type 2 diabetes, reports nausea in 15.8% of people on 0.5 mg and 20.3% on 1 mg, against 6.1% on placebo.
Overall, 73% of adults on Wegovy injection in the weight trials reported a stomach-related side effect, compared with 47% on placebo. Severe stomach reactions were reported in 4.1% versus 0.9%, and 4.3% stopped treatment because of a stomach side effect, compared with 0.7% on placebo. The label also cautions that rates from one drug’s trials cannot be directly compared with another’s, which matters if you are weighing semaglutide vs. tirzepatide.
When do semaglutide side effects start, and how long do they last?
For most people, side effects cluster around the start of treatment and each dose increase. The Wegovy label raises the weekly dose every 4 weeks specifically to reduce stomach side effects, and it suggests delaying the next increase by 4 weeks if a dose is not tolerated. In the STEP 1 trial, nausea and diarrhea were typically transient, mild to moderate, and subsided with time.
A 2022 expert consensus on stomach side effects of GLP-1 medicines gives a more detailed picture:
| Symptom | Typical pattern (2022 expert consensus) |
|---|
| Nausea | Most common in the first 4 to 5 weeks; usually clears 8 days or less after it begins |
|---|
| Vomiting | Less common than nausea; reported to clear in 1 to 8 days |
|---|
| Diarrhea | Starts in the first 4 weeks, then becomes much less common; lasted about 3 days in people with obesity |
|---|
| Constipation | Can start in the first 16 weeks; lasted a median of 47 days in people with obesity, longer than the others |
|---|
If a symptom lasts longer than that, keeps you from eating or drinking, or gets worse, call your doctor rather than pushing through.
Semaglutide nausea: what actually helps
Semaglutide slows how fast your stomach empties, which helps you feel full sooner and is why a large or greasy meal can sit badly. The expert consensus panel recommends these habits, and a 2026 nutrition review on semaglutide and tirzepatide makes the same points:
- Eat slowly, choose smaller portions, and stop at the first sense of fullness.
- Pick easy-to-digest, lower-fat foods. Baked, grilled, or boiled sits better than fried.
- Avoid lying down right after a meal, and avoid eating close to bedtime.
- Sip fluids in small amounts through the day. If fullness or nausea is a problem, drink between meals rather than with them.
- Try cool or room-temperature foods, which many people find less nauseating than hot, strongly scented dishes, and avoid strong smells.
- Keep a short food diary to spot the meals or meal times that make it worse.
The consensus panel also lists crackers, apples, mint, and ginger as foods some people find soothing. The 2026 review is candid that these are practical suggestions rather than proven treatments, and that persistent or severe symptoms call for a medical check and a possible dose change. For a full food guide, see what to eat on semaglutide. Alcohol is one of the common triggers the review lists; our semaglutide and alcohol guide covers drinking in detail.
Semaglutide constipation: prevention and relief
Constipation was reported by 24% of adults on Wegovy 2.4 mg versus 11% on placebo, and it tends to outlast the other stomach symptoms. The consensus notes that people often drink less when they feel full, which makes constipation more likely. Its advice:
- Drink generous amounts of water or other sugar-free fluids.
- Make sure your diet has enough fiber, and add it gradually. The 2026 review warns that a sudden jump in fiber can worsen bloating and cramps.
- Move more. Regular physical activity supports bowel function.
- Ask Dr. Espinet before starting a stool softener or laxative, so she can check that it fits your health and your other medicines.
After approval, the Wegovy label also lists reports of severe constipation, including fecal impaction, and intestinal blockage (ileus). Call promptly if constipation comes with worsening belly pain, swelling, or vomiting.
Semaglutide headache and fatigue
Headache was reported by 14% of adults on Wegovy 2.4 mg and 10% on placebo. Fatigue, which the label groups with weakness, was reported by 11% versus 5%. The label does not say why, but two practical causes are worth ruling out. The first is fluids: the Medication Guide stresses drinking fluids because nausea, vomiting, and diarrhea can dehydrate you, and the 2026 review notes that drinking too little can make nausea, fatigue, and constipation worse. The second is food: when appetite drops sharply, the same review notes that fatigue can follow if energy and protein intake fall too far.
If you have type 2 diabetes, headache, shakiness, sweating, and dizziness can also signal low blood sugar, a risk the label highlights for people also taking insulin or a sulfonylurea. Dizziness was reported by 8% on Wegovy 2.4 mg versus 4% on placebo. Protein spread across your meals also helps protect muscle as you lose weight; see muscle loss on GLP-1 medication.
Semaglutide sulfur burps, bloating, and heartburn
Burping (eructation) was reported by 7% of adults on Wegovy 2.4 mg and fewer than 1% on placebo. Many people call these sulfur burps because they smell like rotten eggs. The label lists burping but does not describe a smell or explain one, and we have not found good research on sulfur burps specifically, so be wary of confident explanations online.
Indigestion, bloating, gas, and heartburn are on the label too. The consensus habits for nausea are a sensible starting point for all of them: smaller, slower, lower-fat meals, and no lying down after eating. The 2026 review also lists fizzy drinks and sugar alcohols, such as the sorbitol or xylitol in sugar-free gum and candy, among common triggers worth cutting back. If burping or heartburn comes with severe stomach pain or vomiting that will not stop, call promptly.
Serious semaglutide side effects: when to call right away
Serious reactions are uncommon, but these are the warning signs the Wegovy label describes.
| Warning sign | What it can mean (Wegovy label) |
|---|
| Severe stomach pain that will not go away, sometimes reaching the back, with or without vomiting | Possible pancreatitis. Stop semaglutide and call your provider right away |
|---|
| Pain in the upper stomach, fever, yellow skin or eyes, or clay-colored stools | Possible gallbladder problems. Gallstones were reported in 1.6% on Wegovy injection vs 0.7% on placebo |
|---|
| Nausea, vomiting, or diarrhea that will not go away | Dehydration, which can lead to kidney problems. Drink fluids and call promptly |
|---|
| Swelling of the face, lips, tongue, or throat, trouble breathing or swallowing, severe rash, or fainting | A serious allergic reaction. Stop the medication and get medical help right away |
|---|
| A lump or swelling in the neck, hoarseness, trouble swallowing, or shortness of breath | Possible thyroid tumor, the risk behind the label’s boxed warning |
|---|
| Shakiness, sweating, confusion, or a fast heartbeat in someone with diabetes | Low blood sugar |
|---|
| Heart racing or pounding at rest for several minutes | Increased heart rate, which the label says to report |
|---|
| Vision changes in someone with type 2 diabetes | Possible worsening of diabetic eye disease |
|---|
About the boxed warning: in rodents, semaglutide caused thyroid C-cell tumors. It is unknown whether it does this in people, but anyone with a personal or family history of medullary thyroid carcinoma (MTC), or with multiple endocrine neoplasia type 2 (MEN 2), should not take it. Before any procedure, tell your surgeon or anesthesia team that you take semaglutide, because slower stomach emptying can raise the risk of food entering the lungs under anesthesia or deep sedation.
One recent update is worth knowing. The Wegovy label’s list of recent changes shows the warning on suicidal behavior and ideation was removed in January 2026. Even so, new or worsening low mood is always worth raising with your doctor, and if you have thoughts of harming yourself, call or text 988 right away.
Less common side effects: hair loss, skin sensations, and taste
Hair loss was reported by 3.3% of adults on Wegovy 2.4 mg (4% of women, 0.9% of men) versus 1% on placebo, and the label ties it to weight reduction; see our GLP-1 hair loss guide. Changes in skin sensation, such as tingling, burning, or sensitive skin (dysesthesia), were reported by 2% on 2.4 mg versus 1% on placebo. The label says they become more common at higher doses: in the trials of the newer 7.2 mg dose, they were reported by 22% on 7.2 mg, 6% on 2.4 mg, and 0.3% on placebo. Taste changes (1.7% vs 0.5%) and injection site reactions such as itching or redness (1.4% vs 1%) were uncommon.
How MeliOra handles semaglutide side effects
At MeliOra, Dr. Espinet sees you herself: through house calls at your home or office across Tampa Bay, at the Lutz office for select appointments, or by secure video visit anywhere in Florida. Before prescribing, she reviews your history for conditions that rule semaglutide out or call for extra caution, such as thyroid cancer history, pancreatitis, gallbladder or kidney disease, and diabetes medicines that can cause low blood sugar.
Once you start, side effects are a reason to adjust, not to endure. In line with the label’s approach, Dr. Espinet can hold a dose step or slow the next increase when symptoms flare, and you can call or text between visits. Your monthly price, from $150/month, covers physician visits, lab work, the medication and supplies, and dose adjustments and check-ins, with no consultation fee and no travel fee. If side effects keep getting in the way, some patients consider another medication; see tirzepatide side effects and switching from semaglutide to tirzepatide.
Frequently asked questions
What are the most common side effects of semaglutide?
The most common side effects of semaglutide are nausea, diarrhea, vomiting, constipation, and stomach pain. In the Wegovy trials, nausea affected 44% of adults on the 2.4 mg dose versus 16% on placebo. Most stomach side effects are mild to moderate and happen most often while the dose is being increased.
How long do semaglutide side effects last?
Most semaglutide side effects are temporary and ease within days to weeks. A 2022 expert consensus reports that nausea usually clears 8 days or less after it begins, while constipation lasts longer, a median of 47 days in people with obesity. Symptoms that last longer or get worse should be reported to your doctor.
How do you stop nausea on semaglutide?
Eating smaller, slower, lower-fat meals and stopping at the first sign of fullness are the main ways to ease semaglutide nausea. Sipping fluids between meals and not lying down after eating also help many people. If nausea persists, your doctor may hold your dose or slow the next increase.
Does semaglutide cause headaches?
Yes, headache is a listed side effect of semaglutide, reported by 14% of adults on Wegovy 2.4 mg and 10% on placebo. Dehydration and eating too little are worth ruling out, and in people with diabetes a headache can also signal low blood sugar.
Does semaglutide make you tired?
Yes, semaglutide can make some people tired. Fatigue was reported by 11% of adults on Wegovy 2.4 mg versus 5% on placebo. Low fluid intake and eating too little can contribute, so mention lasting tiredness to your doctor.
Why does semaglutide cause sulfur burps?
The cause of sulfur burps on semaglutide has not been well studied. The Wegovy label lists burping in 7% of adults on 2.4 mg versus fewer than 1% on placebo, but it does not describe a sulfur smell or explain it. Smaller, slower, lower-fat meals and fewer fizzy drinks are reasonable first steps.
When should I worry about semaglutide side effects?
Get medical care right away for severe stomach pain that will not go away, signs of a serious allergic reaction, or vomiting or diarrhea that keeps you from holding down fluids. Also call your doctor for yellow skin or eyes, upper stomach pain with fever, a lump in your neck, or a racing heartbeat at rest.
Do semaglutide side effects get worse when the dose goes up?
They often flare briefly after a dose increase. The labels say stomach side effects are reported most often during dose escalation, which is why the dose is raised slowly in 4-week steps. If a step is hard to tolerate, the Wegovy label suggests delaying the next increase.
Related Services
Sources & References
Ready to take the next step?
Serving Lutz, Wesley Chapel, Land O'Lakes, Carrollwood, New Tampa & greater Tampa Bay.
Book Your Consultation
