Semaglutide: what it is, what it costs, and who sells it

Semaglutide is a synthetic peptide engineered to activate the GLP-1 hormone receptor, the same gut-hormone signal the body releases after eating. FDA has approved several branded products built on it — Wegovy (injection, for chronic weight management), Ozempic (injection, for type 2 diabetes), and a newer Wegovy tablet — confirmed directly against FDA's own Drugs@FDA record, which lists Wegovy's marketing status as “Prescription.”

A compounded semaglutide product is a different thing: a pharmacy-prepared version made under the same narrow federal exemption (21 U.S.C. §353a) tirzepatide uses. Volume compounding depended on an FDA-declared shortage, and FDA declared the semaglutide shortage resolved in February 2025, so pharmacies may now compound it only within narrower rules. It is not a generic and not independently reviewed by FDA the way the branded pens are — and it is the product almost every telehealth provider on the board below actually sells.

Semaglutide activates the GLP-1 receptor alone — one target, versus tirzepatide's two. That single mechanism slows gastric emptying, boosts insulin release when blood sugar is high, and reduces appetite. STEP 1, the trial that established semaglutide's 2.4 mg weight-management dose, randomized 1,961 adults to semaglutide or placebo for 68 weeks and reported -14.9% body weight versus -2.4% for placebo. In the one trial that has put semaglutide and tirzepatide head to head, semaglutide came in second — read the full comparison, including why that doesn't make it the weaker choice for everyone, in our full tirzepatide-vs-semaglutide review.

The same compounding rule that governs tirzepatide applies to semaglutide: a pharmacy may compound it because it is the active ingredient in an FDA-approved drug, and could sell it in volume only while the reference brand was in an FDA-declared shortage. FDA declared semaglutide's shortage resolved in February 2025, about four and a half months after tirzepatide's.

For the complete regulatory timeline and every provider's own pharmacy-sourcing disclosure, see is compounded semaglutide still legal? and what compounded semaglutide actually is, both read directly off the statute and FDA's own guidance.

The dominant signal in semaglutide's own trial data is the same drug-class pattern tirzepatide shows: gastrointestinal. In STEP 1, nausea and diarrhea were the most common adverse events reported, and the trial's own results describe them as “typically transient and mild-to-moderate in severity” — which is what the label's four-week dose-escalation steps exist to reduce, not eliminate.

For what the Wegovy and Ozempic labels report, dose by dose, see our semaglutide side-effects review; for the escalation-pause language and the missed-dose rule, see our semaglutide dosing reference. None of this is a recommendation for or against starting semaglutide — talk to a licensed clinician about your own situation.