Semaglutide

Semaglutide is the GLP-1 receptor agonist peptide that started the modern weight-loss era, approved as Ozempic (type 2 diabetes), Wegovy (weight management), and Rybelsus (oral tablets). Because approved versions exist everywhere, its gray-market “research” form sits in the most heavily enforced corner of the peptide market.

How semaglutide works

It mimics the incretin hormone GLP-1: appetite suppression, slower gastric emptying, improved insulin response. In its pivotal weight-management trial (STEP 1), weekly semaglutide averaged roughly 15% body-weight reduction at 68 weeks.

Approved drug vs. research-grade gray market

Pharmacy semaglutide is GMP-manufactured with verified contents. Research-grade vials are unregulated powder whose quality is only as good as the vendor’s published third-party testing. Semaglutide batches appear regularly in failed-label-claim results. Enforcement is aggressive: in Canada, semaglutide’s approved status puts gray-market versions in a worse category at the border (Canada guide).

Tested batches and vendors

Working out reconstitution or syringe units? Use the free peptide calculator, then check your batch’s published test result before trusting the label: in 2024, roughly 43% of research peptides submitted to Janoshik Analytical missed their label claims.

Vendor rankings on PeptideCensus are computed only from publicly published third-party lab results; see the vendor index and how scoring works.

Side effects

Per the approved products’ labeling: gastrointestinal effects dominate (nausea, vomiting, diarrhea, constipation), dose-related and concentrated during escalation.

Common questions

Is semaglutide a peptide?

Yes: a modified 31-amino-acid GLP-1 analog engineered for once-weekly action.

Is research-grade semaglutide legal?

Sold “for research use only,” but with approved versions on the market, unauthorized sales and imports draw the strictest enforcement in this space.

Semaglutide vs tirzepatide vs retatrutide?

One, two, and three receptors , with successively larger average weight reductions in their separate trials. See the tirzepatide and retatrutide hubs.

Why is compounded semaglutide controversial?

Compounding was permitted during official shortages; as shortage status changed, regulators moved against mass compounded versions. The rules keep shifting, so check the current status as of the date you read this.

PeptideCensus aggregates publicly published third-party lab results and links every number to its source. Nothing on this page is medical advice; research compounds are not for human use.

Dosing math: use the free peptide calculator to work out reconstitution and syringe units — then check your vial’s published batch result before relying on the label.