What semaglutide is
Semaglutide itself is an active ingredient, not a single product. Sold as Wegovy (weight loss), Ozempic and Rybelsus (type 2 diabetes). Compounded versions are not FDA-approved. See our compounded GLP-1 guide.
Dosing
Weekly injection or daily pill. For weight loss, weekly injections step from 0.25 mg to 2.4 mg over about 16 weeks. Your clinician sets the pace, and it is common to stay at a dose longer if side effects are hard to manage.
How well it works
14.9% average weight loss over 68 weeks with Wegovy 2.4 mg in STEP 1. These are averages from clinical trials; your results may be different.
Semaglutide cost
Wegovy self-pay is $349 to $399 after two $199 starter fills for new patients. For every price option, read How much does Wegovy cost in 2026?. For the steps, read How to get the Wegovy pill online.
Common side effects
Stomach-related side effects are the most common, especially while the dose is going up. Percentages show people on the medication vs placebo in the label trials.
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| Side effect | Wegovy 2.4 mg | Zepbound 5–15 mg | Foundayo |
|---|---|---|---|
| Nausea | 44% vs 16% | 25–29% vs 8% | 26–35% vs 10% |
| Diarrhea | 30% vs 16% | 19–23% vs 8% | 21–25% vs 11% |
| Vomiting | 24% vs 6% | 8–13% vs 2% | 13–24% vs 4% |
| Constipation | 24% vs 11% | 11–17% vs 5% | 20–27% vs 9% |
| Abdominal pain | 20% vs 10% | 9–10% vs 5% | 13–14% vs 7% |
| Fatigue | 11% vs 5% | 5–7% vs 3% | 6–9% vs 4% |
| Hair loss | 3% vs 1% | 4–5% vs 1% | 4–5% vs 2% |
Source: Wegovy (rev. 06/2026), Zepbound (rev. 08/2026) and Foundayo (rev. 07/2026) prescribing information.
Safety: GLP-1 medications carry a boxed warning for thyroid C-cell tumors and are not for people with a personal or family history of medullary thyroid carcinoma or MEN 2. Labels also warn about pancreatitis, gallbladder problems, low blood sugar with some diabetes drugs, kidney problems from dehydration and severe stomach problems. Talk to a licensed clinician about your history.
Legal status: Prescription only; sold as FDA-approved brand-name drugs; compounded versions are not FDA-approved.