Peptide basics
Ozempic and Wegovy are the same molecule with different labels
On this page
A molecule has one generic name. The products containing it can have many brand names.
Semaglutide appears in the FDA's approval records under six brand entries, including Ozempic, Wegovy and Rybelsus.
Tirzepatide appears under five, including Mounjaro and Zepbound.
The brands differ in what they were approved to treat and how they are presented. The molecule inside is the same one, and the trial evidence attaches to the molecule.
This page explains the relationship between brand names and active ingredients, using the approval record. It does not compare products, recommend one, or give any dose, schedule or route.
Three names for every drug
Every approved drug carries a chemical name almost nobody uses, a generic name assigned internationally, and one or more brand names owned by whoever sells it. The generic name is the stable one: it identifies the molecule and does not change between countries or companies.3
The suffix is a clue. Under the international naming system, -tide marks a peptide, which is why semaglutide, tirzepatide, liraglutide, dulaglutide and exenatide all end the same way. They are relatives by construction, not by coincidence.3
What the approval record actually shows
Searching the FDA's approval database by active ingredient rather than brand returns every product built on that molecule. For semaglutide that is six distinct brand entries; for tirzepatide, five; for liraglutide, four including a combination product.12
- Semaglutide: Ozempic, Wegovy, Rybelsus and related presentations.
- Tirzepatide: Mounjaro, Zepbound and related presentations.
- Liraglutide: Victoza, Saxenda and a combination product.
- Exenatide: Byetta, Bydureon and related presentations.1
The brands are not interchangeable in practice — they were approved for different conditions, come in different presentations, and are priced differently. But they are not different drugs in the sense people usually mean when they ask which one is better.1
Why this trips people up
Almost all public conversation happens in brand names, because that is what appears on packaging and in advertising. Almost all the evidence is published under generic names, because that is what trials register under.13
The result is a persistent mismatch: someone searching a brand finds marketing, and someone searching the molecule finds trials. Learning the generic name for whatever you are reading about is the single most useful move available.3
Common questions
Is Wegovy just Ozempic in a different box?
Same active ingredient, different approved indication and presentation. They are separate approvals with separate labels, which is why they are prescribed for different things.
Why does the same molecule need two approvals?
An approval covers a specific product for a specific use. Studying a molecule for a second condition means a separate application supported by separate trials.
Does a compounded version count as one of these brands?
No. A compounded preparation is not an approved product and does not appear in the approval record at all, whatever it is called.
Sources
- RegulatoryDrugs@FDA — approved products by active ingredientU.S. Food and Drug Administration, 2026www.accessdata.fda.gov/scripts/cder/daf/ ↗↩ Back to text
- RegulatoryopenFDA Drugs@FDA API — brand name and active ingredient fieldsU.S. Food and Drug Administration, 2026open.fda.gov/apis/drug/drugsfda/ ↗↩ Back to text
- RegulatoryWHO — International Nonproprietary Names (INN) programmeWorld Health Organization, 2025www.who.int/teams/health-product-and-policy-standards/inn ↗↩ Back to text