Research guide · Published July 22, 2026 · Sources checked July 22, 2026

Semaglutide vs tirzepatide vs retatrutide: a research comparison

Semaglutide, tirzepatide, and retatrutide are three distinct modified peptides, not different strengths of one material. Each has separate nomenclature, structural records, and lot-specific documentation requirements.

Short answer

The full material name, literature identifier where applicable, CAS registry number, and lot-linked analytical record distinguish these materials. A name or catalog shorthand does not verify the identity or composition of a supplied batch.

Evidence boundary: This page is limited to nomenclature and analytical-documentation boundaries. It provides no preparation, dosing, administration, or human-use guidance. Catalog materials are supplied only for lawful nonclinical research and are not for human or animal use.

Comparison at a glance

Research dimensionSemaglutideTirzepatideRetatrutide
CAS Registry Number910463-68-22023788-19-22381089-83-2
Literature identifierSemaglutideLY3298176LY3437943
Catalog shorthandGLP-1 / SemaGLP-2 / TirzepGLP-3 / Reta
Verification requirementLot-linked analytical recordLot-linked analytical recordLot-linked analytical record

How to interpret the comparison

Compare material identity at the level of full name, identifier, structural or sequence record, material format, and lot number. Catalog shorthand is an index label, not a chemical identity.

A Certificate of Analysis should identify the tested sample or lot and the analytical method used. A generic document or literature citation cannot verify an independently supplied batch.

Primary sources

  1. Lau et al., Journal of Medicinal Chemistry (2015) — Primary literature describing the molecular design and structural modifications of semaglutide study material. DOI: 10.1021/acs.jmedchem.5b00726
  2. Coskun et al., Molecular Metabolism (2018) — Primary literature identifying LY3298176 and describing its study-material design. DOI: 10.1016/j.molmet.2018.09.009
  3. Coskun et al., Cell Metabolism (2022) — Primary literature identifying LY3437943 and describing its study-material design. DOI: 10.1016/j.cmet.2022.07.013

Continue in the research library

Prepared by The Pep Labs Research Editorial Team. This evidence summary is not medical advice and contains no dosing or administration guidance.