Editorial explainer
Is tirzepatide a peptide or a GLP-1?
Oliver Mackman · Editorial director · Best Business Loans Ltd (16833937)
Last updated 2026-06-11
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Tirzepatide is both. It is a synthetic peptide, a chain of amino acids, and it works as a dual agonist on the GIP and GLP-1 receptors. So calling it simply "a GLP-1" is a useful shorthand but not strictly accurate: GLP-1-only medicines such as semaglutide act on one receptor, while tirzepatide acts on two. In the UK it is sold under the brand name Mounjaro and is a prescription-only medicine. PeptideClear is editorial commentary, not clinical advice; whether tirzepatide is appropriate for anyone is a decision for a UK-licensed prescriber.
Peptide, GLP-1, GIP: getting the words straight
The confusion comes from mixing two different kinds of label. "Peptide" describes what the molecule is: a short chain of amino acids. "GLP-1 receptor agonist" describes what part of the molecule does: it activates the GLP-1 receptor. Those are not competing answers. Tirzepatide is a peptide whose action includes the GLP-1 receptor, and also the GIP receptor.
That dual action is the headline difference from the GLP-1-only peptides. Semaglutide, the active ingredient in Ozempic and Wegovy, is a peptide that acts on the single GLP-1 receptor. Tirzepatide adds GIP receptor activity on top. Both sit in the same broad family of peptide-based metabolic medicines, and both are prescription-only.
None of that is a recommendation. Which medicine, if any, suits a given person is a clinical decision. The purpose here is only to clear up the category, because the labels are used loosely everywhere else.