Ozempic Semaglutide Side Effects: Complete List

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At a glance

Side effect	How common (Wegovy 2.4 mg)	Notes
Nausea	~44%	Most common; worst after dose increases
Diarrhea	~30%	Usually short-lived per episode
Vomiting	~24%	Contact a clinician if you can't keep fluids down
Constipation	~24%	Can linger longer than other GI effects
Abdominal pain	~20%	Severe pain radiating to the back = seek care
Headache	~14%	Often eases with hydration
Fatigue	~11%	Often from under-eating early on

Side-effect rates are from trials of the FDA-approved branded medications (Wegovy, Ozempic) and are averages, not individual predictions. Information is current as of June 2026.

What are the most common Ozempic and semaglutide side effects?

In Wegovy's pooled trials, the GI effects led: nausea ~44%, diarrhea ~30%, vomiting ~24%, constipation ~24%, plus abdominal pain ~20%, headache ~14%, and fatigue ~11% — per the FDA-approved Wegovy prescribing label. The vast majority were mild-to-moderate (about 98% in the trials) and tied to dose escalation. These figures are from the FDA-approved branded semaglutide; compounded semaglutide was not studied and is not FDA-approved. The STEP 1 trial (Wilding et al., NEJM 2021) is the foundational efficacy study on the semaglutide 2.4 mg molecule.

Why do side effects happen — and when do they ease?

GLP-1s slow gastric emptying and act on appetite pathways — which is also why they cause GI symptoms. They tend to spike after each dose increase, then settle over the following weeks as the body adjusts. For most people they improve at a stable dose; see how long Ozempic side effects last. The NIDDK overview of prescription medications for obesity provides a plain-language summary of how this drug class works and what to expect.

How to manage the common ones

The biggest lever is slow titration. Beyond that: for nausea, eat small, bland, lower-fat meals and stop at first fullness (full nausea guide); for constipation, add fiber, fluids, and movement (constipation guide). Do Wegovy and Ozempic have the same side effects? Yes — they're the same drug; Wegovy is dosed higher for weight loss. If you're starting semaglutide for the first time, knowing what week-by-week to expect can reduce anxiety and improve adherence.

When is a side effect serious?

Rare but important: a boxed warning for thyroid C-cell tumors (contraindicated with a personal/family history of medullary thyroid cancer or MEN 2), pancreatitis, and gallbladder disease. The FDA's human drug compounding guidance also provides context on the regulatory framework for compounded medications. In 2023, the SELECT trial (Lincoff et al., NEJM 2023) found a cardiovascular benefit for semaglutide 2.4 mg in adults with established CVD and obesity — relevant context for the overall benefit-risk picture. See serious Ozempic side effects & warnings for the full red-flag symptoms and when to seek care. For the tirzepatide comparison, see Mounjaro & Zepbound side effects, which draws on the Zepbound FDA prescribing label and the SURMOUNT-1 trial (Jastreboff et al., NEJM 2022).

Related side-effect guides

• Mounjaro & Zepbound Side Effects
• Ozempic Nausea: How to Manage It
• Ozempic Constipation: Relief
• Starting Ozempic: What to Expect
• How Long Do Ozempic Side Effects Last?
• "Ozempic Face": Causes & Prevention
• Does Ozempic Cause Hair Loss?
• Serious Ozempic Side Effects & Warnings
• Sulfur Burps on Ozempic

How Nouri helps you manage side effects

Most GLP-1 side effects are manageable, and the single biggest factor is slow dose titration — starting low and increasing gradually. Nouri includes ongoing support from the Nouri Care Team, who can slow your titration, adjust your plan, and help you handle symptoms whenever they flare — alongside a nutrition plan that targets GI side effects directly. Not everyone qualifies; see who typically qualifies for GLP-1 treatment and learn how online GLP-1 programs work.

The Program includes compounded semaglutide from $120/month and compounded tirzepatide from $175/month — see the full 2026 GLP-1 cost breakdown for a side-by-side comparison. Compounded GLP-1 medications are not FDA-approved and are not the same as the brand-name drugs. The Nouri Promise: if you're not satisfied in your first 30 days, you get a full refund — available on 3-month and 6-month plans.

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Frequently asked questions

What are the most common side effects of Ozempic?

The most common are gastrointestinal: nausea (~44% in Wegovy's trials), diarrhea (~30%), vomiting (~24%), and constipation (~24%), along with abdominal pain, headache, and fatigue. They're usually mild-to-moderate and worst after a dose increase. These rates come from trials of the FDA-approved branded medication; compounded semaglutide was not studied.

What are the side effects of Ozempic in women?

Women experience the same core GI side effects (nausea, diarrhea, constipation). Some appearance-related effects of rapid weight loss — like facial volume loss ("Ozempic face") and temporary hair shedding — are reported more in women; these come from the weight loss itself, not a drug toxicity.

Does Wegovy have the same side effects as Ozempic?

Yes — they're the same drug (semaglutide). Wegovy is dosed higher (up to 2.4 mg) for weight loss, so side effects can be a bit more frequent, but the profile is the same.

What is the most common side effect of semaglutide?

Nausea — reported by about 44% of people in Wegovy's trials. It's usually mild-to-moderate and tends to ease over the first weeks at a stable dose.

Do Ozempic side effects go away?

For most people, yes — the common GI side effects are usually transient and improve over weeks at a stable dose, though they can return briefly after each dose increase. A small percentage stop the medication due to side effects they can't tolerate.

Does Ozempic cause hair loss or "Ozempic face"?

It can be associated with temporary hair shedding and facial volume loss — but these come from rapid weight loss, not a drug toxicity, and the hair usually regrows. See our guides on Ozempic hair loss and "Ozempic face."

Sources & references

• Wegovy prescribing information and side-effect data (FDA label, 2026)
• Zepbound FDA prescribing label (2025)
• Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). NEJM 2021.
• Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). NEJM 2022.
• Lincoff AM et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (SELECT). NEJM 2023.
• NIDDK. Prescription Medications to Treat Overweight & Obesity. National Institutes of Health.
• FDA. Human Drug Compounding. U.S. Food & Drug Administration.

Medically reviewed by Amber Patel, MD. Nouri content is reviewed by licensed clinicians and updated as guidance changes.

This article is general information, not individual medical advice — talk to your clinician about your symptoms, and seek urgent care for the red-flag symptoms described here. Side-effect rates come from clinical trials of the FDA-approved branded medications (Wegovy, Ozempic); compounded semaglutide and tirzepatide were not studied in these trials, are not FDA-approved, and are not the same as, or therapeutically equivalent to, the brand-name drugs. GLP-1 medications carry a boxed warning for thyroid C-cell tumors and are contraindicated with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). Ozempic®, Wegovy® and Rybelsus® are registered trademarks of Novo Nordisk; Mounjaro® and Zepbound® of Eli Lilly; Nouri is not affiliated with these companies. Information is current as of June 2026.