Molecule hub
Semaglutide
One molecule, three brands: Ozempic and Rybelsus for diabetes, Wegovy for weight management. The headline obesity trial figures come from the Wegovy program.
Educational only — not medical advice, no doses, no sourcing.
At a glance
Semaglutide is a GLP-1 receptor agonist made by Novo Nordisk. It is sold as Ozempic (approved for type 2 diabetes), Wegovy (approved for chronic weight management), and Rybelsus (an oral tablet for type 2 diabetes). The molecule is the same across the injectable brands; what differs is the approved use and the doses studied for each.
- Molecule
- Semaglutide
- Class
- a GLP-1 receptor agonist
- Receptor profile
- Single incretin target: GLP-1
- Maker
- Novo Nordisk
- Status
- FDA-approved (see brands)
The brands that carry it
Semaglutidea GLP-1 receptor agonist
- Ozempictype 2 diabetes (and cardiovascular-risk reduction in those with heart disease)
- Wegovychronic weight management, and cardiovascular-risk reduction
- Rybelsustype 2 diabetes — the oral (tablet) form
What the evidence shows
- Are Ozempic and Wegovy the same drug?Yes — Ozempic and Wegovy are the same molecule, semaglutide, from the same manufacturer. They differ by brand name, FDA-approved use, and approved dose range: Ozempic is approved for type 2 diabetes, Wegovy for chronic weight management. Those different labels are why insurers cover them differently.Read the evidence →
- Semaglutide side effects: what the evidence actually showsMost semaglutide side effects are gastrointestinal — nausea, vomiting, diarrhea, and constipation — usually mild-to-moderate, tied to dose increases, and easing over time; this is established from large randomized trials and the FDA label. Serious problems (pancreatitis, gallbladder disease, bowel obstruction, kidney injury from dehydration) are uncommon but real and documented. Newer signals — a rare eye condition (NAION) and gastroparesis-related litigation — are real but largely observational, not proof of a precise risk. A short list of red-flag symptoms warrants prompt clinical contact.Read the evidence →
- Semaglutide vs tirzepatide: how they really compareBoth are highly effective GLP-1-based medicines with broadly similar gastrointestinal side-effect profiles and the same class warnings (boxed rodent-thyroid, pancreatitis, gallbladder, hypoglycemia in combination). The clearest difference is average weight loss: in the head-to-head SURMOUNT-5 obesity trial, tirzepatide produced more weight loss than semaglutide (−20.2% vs −13.7% at 72 weeks), and tirzepatide is a dual GIP/GLP-1 agonist while semaglutide acts on GLP-1 alone. But 'more on average' is not 'right for you.' A few genuinely drug-specific points matter: tirzepatide's label carries an oral-contraception warning that semaglutide's does not; semaglutide's diabetes label carries a diabetic-retinopathy warning; the NAION eye signal is better characterized for semaglutide; and the cardiovascular evidence differs in kind (semaglutide has placebo-controlled obesity outcomes from SELECT; tirzepatide has an active-comparator non-inferiority diabetes trial, SURPASS-CVOT). Which drug, and whether to switch, is a clinician decision.Read the evidence →
- Oral semaglutide: what the GLP-1 pill is, and what the evidence showsOral semaglutide is the same medicine as injectable semaglutide (Ozempic/Wegovy), rebuilt as a once-daily tablet using an absorption enhancer called SNAC. The low-dose tablet (Rybelsus) has been FDA-approved for type 2 diabetes since 2019; a higher-dose 25 mg tablet was approved in December 2025 for weight management — the first oral GLP-1 for weight loss. It is the same molecule and the same GLP-1 side-effect profile as the shot, so a pill is not inherently 'weaker' or 'safer,' and no head-to-head trial shows the pill beats or loses to the injection on outcomes.Read the evidence →
- Ozempic vs Wegovy vs Mounjaro vs Zepbound: the brand decoderFour brands, two molecules. Ozempic and Wegovy are both semaglutide, a GLP-1 receptor agonist. Mounjaro and Zepbound are both tirzepatide, which adds a second incretin target, GIP. Within each pair, the diabetes brand and the weight-management brand share the molecule but differ in approved use.Read the evidence →
Sources
FDA labelaccessdata.fda.gov ↗Drugs@FDA: Ozempic (semaglutide) approval record (NDA 209637)FDA labeldailymed.nlm.nih.gov ↗WEGOVY (semaglutide) — FDA Prescribing Information (DailyMed)
Hard facts on this page (molecule, class, maker, approved uses) are label- or trial-verified. This page describes a molecule; it is not a recommendation, a comparison of “which is best,” or advice to start, stop, or source anything.