Semaglutide vs Tirzepatide
The core difference is receptor coverage. Semaglutide acts on the GLP-1 receptor only; tirzepatide acts on both the GIP and GLP-1 receptors. Both are fatty-acid-modified for a long half-life and both are approved medicines, so both sit at the top of our evidence scale.
Long-acting GLP-1 receptor agonist
Choose Semaglutide if
- ✓ You need a GLP-1-only reference compound
- ✓ You are replicating the largest body of published incretin literature
Dual GIP and GLP-1 receptor agonist
Choose Tirzepatide if
- ✓ Your question is about dual GIP/GLP-1 signalling
- ✓ You are comparing dual versus single agonism head to head
Side-by-side specification
| Compare | Semaglutide Long-acting GLP-1 receptor agonist | Tirzepatide Dual GIP and GLP-1 receptor agonist |
|---|---|---|
| Class | GLP-1 receptor agonist | Dual GIP / GLP-1 receptor agonist |
| Research area | Metabolic | Metabolic |
| Receptor targets | GLP-1R | GIPR, GLP-1R |
| Length | 31 amino acids (acylated GLP-1 analogue) | 39 amino acids (acylated) |
| Molecular mass | ≈ 4.11 kDa | ≈ 4.81 kDa |
| Origin | Synthetic analogue of human GLP-1 | Synthetic, GIP-based sequence |
| Evidence level | 5/5 Approved drug, phase 3 trials | 5/5 Approved drug, phase 3 trials |
| Regulatory status | Approved prescription medicine | Approved prescription medicine |
| Nordapep from | Not listed | Not listed |
| Best price per mg | Not listed | Not listed |
| View Semaglutide at Nordapep → | View Tirzepatide at Nordapep → |
What separates them
For research, semaglutide is the single-receptor reference. Tirzepatide is the natural next step when the question is what GIP-receptor activity adds.
Read the full guides for Semaglutide and Tirzepatide, or add a third compound in the comparison tool.
FAQ
Which has more research behind it?
Semaglutide has been studied for longer, but both have large phase 3 programmes behind their approved forms.
Can I buy both from Nordapep?
Yes. Both are listed with batch-matched Certificates of Analysis, and the GLP-1 Research Trio bundles them with retatrutide.
Are Semaglutide and Tirzepatide approved medicines?
Semaglutide: Approved prescription medicine. Tirzepatide: Approved prescription medicine. Research-grade material of either is not a medicine and is supplied for in vitro research only.
Where can I buy Semaglutide and Tirzepatide?
Nordapep lists compounds with a Certificate of Analysis matched to the batch reference. Check each compound page for current availability.
More comparisons
Where to buy
Why we send researchers to Nordapep
Comparing compounds is only half the job. The other half is knowing the vial contains what the label says. Nordapep publishes batch documentation for every compound it sells.
Browse the Nordapep catalogue →Each batch reference on the label matches its CoA, so you can check what is in the vial.
Enter the batch reference from your vial into Nordapep's batch-verification tool.
Purity is reported by RP-HPLC, the standard method for peptides of this size.
Bundled stacks for common comparisons, plus tiered pricing for volume orders.