Skip to main content
Peptyds
Science

GLP-1 Peptides Explained: Semaglutide, Tirzepatide, and Retatrutide

Semaglutide is described by EMA as a GLP-1 receptor agonist, tirzepatide acts on GLP-1 and GIP pathways, and retatrutide has been studied as a triple hormone receptor agonist. Read them as related, not interchangeable.

7 min readUpdated 28 Apr 2026Reviewed by Independent EU laboratory (ISO/IEC 17025)
Three abstract peptide-like molecular forms on a navy background, representing GLP-1 peptide research.
Three abstract peptide-like molecular forms on a navy background, representing GLP-1 peptide research.
Jump to section
  1. 01One category, different mechanisms
  2. 02Evidence stage matters before comparison
  3. 03How Peptyds should route GLP-1 readers
  • Semaglutide, tirzepatide, and retatrutide are not the same molecule.
  • EMA pages provide regulated medicine context for semaglutide and tirzepatide products.
  • Retatrutide remains an investigational research context in cited phase 2 literature.
  • Buyer education should separate mechanism, evidence stage, and product quality.

One category, different mechanisms

EMA describes Wegovy's active substance semaglutide as a GLP-1 receptor agonist.[1]

EMA describes tirzepatide, the active substance in Mounjaro, as acting in the same way as GLP-1 and glucose-dependent insulinotropic polypeptide, also called GIP.[2]

Retatrutide has been discussed in peer-reviewed phase 2 literature as a triple-hormone-receptor agonist involving GIP, GLP-1, and glucagon receptor activity.[3]

Evidence stage matters before comparison

A systematic review can compare GLP-1 receptor agonists and polyagonists across trials, but buyers should still separate approved-medicine context from investigational research context.[4][1][2]

This article is educational and does not recommend a medication, dose, or treatment route.[5]

How Peptyds should route GLP-1 readers

A responsible GLP-1 hub should make it easy to compare mechanism context, evidence stage, batch testing, and shipping requirements without making personal medical recommendations.[6][7]

Continue reading:View SemaglutideView TirzepatideView Retatrutide

Sources

  1. [01]
    European Medicines Agency
    Wegovy EPAR
  2. [02]
    European Medicines Agency
    Mounjaro EPAR
  3. [03]
  4. [04]
  5. [05]
  6. [06]
    European Medicines Agency
    Clinical trials in human medicines
  7. [07]

Questions

Are semaglutide, tirzepatide, and retatrutide interchangeable?

No. They are related by incretin biology but differ in receptor activity and evidence context.[1][2][3]

Is retatrutide approved like semaglutide or tirzepatide products?

This article treats retatrutide as an investigational research context based on the cited phase 2 literature, not as an approved medicine recommendation.[3]

Can this article tell me which GLP-1 peptide to use?

No. It explains category context and quality questions. Medical decisions require a qualified healthcare professional.[5]

Educational content. Not medical advice.

Next step

Choose the route that matches how you read.

Shop by goalShop all peptidesRead quality protocolCompare metabolic-support peptides