A plain definition
A peptide is a short chain of amino acids, which are the building blocks used to make proteins.
That definition does not tell you whether an injection has FDA approval, whether it can be compounded, or whether a claim about it is true.
Treat “peptide therapy” as the start of a question, not the answer.
The same word covers very different things
Approved medicine
Semaglutide (Ozempic, Wegovy) holds FDA approval as a peptide medicine, as of September 2026.
Made to order
A compounded medicine, one a pharmacy mixes to order, can be lawful, but FDA does not review it before it is supplied.
Research chemical
As of September 2026, a chemical sold online for research is not a legal route to personal treatment, even when the sales page hints at human use.
What this guide does not decide
A webpage cannot decide whether a particular medicine fits a particular person.
The pages ahead help test the care route: who assesses, what is prescribed, who makes it, what the full price includes, and where the claim came from.