Semaglutide vs Retatrutide

Semaglutide is an approved drug with years of real-world use. Retatrutide is an investigational drug that produced very large weight loss in trials, but it wasn’t approved anywhere when this page was last reviewed.

At a glance

The facts side by side. Tap a name for its calculator.

Semaglutide compared with Retatrutide
Semaglutide	Retatrutide
Evidence
Approved drug. Sold as Ozempic and Wegovy.	Investigational. In phase 3 trials; not approved anywhere.
Vial sizes
2, 3, 5, 10 mg	10, 15 mg
Usual dose range
0.25–2.4 mg	1–12 mg
How often
Weekly	Weekly
Unmixed
Freezer −20°C	Freezer −20°C
After mixing
Fridge 2–8°C, use within 28 days	Fridge 2–8°C, use within 30 days

One receptor or three

Semaglutide copies one hormone, GLP-1. Retatrutide acts on three receptors: GLP-1, GIP and glucagon. The glucagon action is thought to raise energy use, which may explain the bigger weight loss seen so far.

Trial results

Semaglutide 2.4 mg: about 15% average weight loss over 68 weeks in a large phase 3 trial. Retatrutide 12 mg: about 24% over 48 weeks in a smaller phase 2 trial. Phase 2 trials are smaller and shorter, and larger phase 3 trials are what decide approval.

What’s sold online

Semaglutide is prescribed as Ozempic and Wegovy. Anything sold online as retatrutide is not the trial drug: it’s an unregulated product, and nobody checks what’s in the vial or how much.

The short version

Semaglutide (or tirzepatide) is the approved option available today. Retatrutide’s trial results are striking, but until it’s approved, anything sold as retatrutide is an unknown product.

Semaglutide calculator Retatrutide calculator