Plain start
Peptides, in plain words
One word is being used for very different things. First work out which of three kinds of product you are looking at. Then ask about the product itself.
THE WORD
A peptide is a small piece of protein
Strip a protein down to a short string of its links and you have a peptide. Insulin counts as one. So does the hormone inside certain weight-loss injections.
The word only says what the substance is made of. It does not tell you what it will do for you, or why someone is offering it.
THREE KINDS
Three very different products can all be called “peptides”
- APPROVEDA medicine with an FDA approval record
The form, label and reason for use all matter.
- MADE TO ORDERA compounded medicine
A pharmacy or doctor prepares it for a patient need.
- RESEARCH LABELA chemical sold outside patient care
The label is not a shortcut into medical treatment.
As of September 2026, two peptide medicines had FDA-approved versions for US patients: semaglutide, under the brand names Ozempic and Wegovy, and tirzepatide, under the brand names Mounjaro and Zepbound. Their approved uses include type 2 diabetes and long-term weight control.
As of September 2026, compounded medicines, meaning medicines a pharmacy makes to order, can be lawfully prepared in some cases, but they are not FDA-approved products.
Stamping “research use only” on a chemical did not, as of September 2026, create a legal way to sell it as treatment for people.
WORDS TO KEEP
A tiny glossary for the next screen
- Clinician
- The person who treats you: a doctor, a physician assistant or a nurse practitioner.
- Prescriber
- The licensed clinician who decides whether a prescription fits your care.
- Pharmacy
- The licensed business that prepares or dispenses the medicine.
- Compounded
- Prepared to order by a pharmacy instead of coming finished from a drug maker.