Semaglutide vs Tirzepatide
This is the comparison with the most published evidence behind it, including head-to-head and real-world comparative studies.
Semaglutide is a single-receptor agonist acting at GLP-1. Tirzepatide is a dual agonist acting at GLP-1 and GIP. The addition of GIP activity is the structural difference, and GIP had been comparatively neglected as a target until tirzepatide's trial results renewed interest in it.
Side by side
| Semaglutide | Tirzepatide | |
|---|---|---|
| GLP-1 receptor activity | Yes | Yes |
| GIP receptor activity | No | Yes |
| Number of receptor targets | One | Two |
| Half-life extension method | C18 fatty di-acid, albumin binding | C20 fatty di-acid, albumin binding |
| Peptide length | 31 amino acids | 39 amino acids |
| Approval status | Approved as a finished pharmaceutical | Approved as a finished pharmaceutical |
| Head-to-head trial data | Yes — published comparative studies | Yes — published comparative studies |
| Supplied as | Lyophilized powder | Lyophilized powder and pre-loaded pens |
Choosing between them
Researchers work with semaglutide when
GLP-1 agonism is the specific mechanism under study, or when the largest available evidence base is needed. Semaglutide has the deepest trial literature of any compound in this catalogue — STEP for weight, SUSTAIN for glycaemic endpoints, SELECT for cardiovascular outcomes.
Researchers work with tirzepatide when
the contribution of GIP is the question. Because the two differ by exactly one receptor, comparing them is one of the cleaner ways to isolate what GIP activity adds on top of GLP-1.
Common questions
What is the actual difference between them?
Why was GIP overlooked before tirzepatide?
Are there published head-to-head studies?
This comparison covers structure, receptor targets and development stage — matters of published record. It does not rank the compounds or claim either produces better outcomes. Much of the supporting literature is preclinical. All products are supplied for laboratory research use only.