Semaglutide vs Tirzepatide

Name: Semaglutide vs Tirzepatide
Published: 2026-10-23

Updated Oct 23, 20266 sources

Key differences

1SURMOUNT-5 tested them head to head (751 adults, 72 weeks, open label): tirzepatide averaged 20.2% weight loss vs 13.7% for semaglutide, and 18.4 vs 13.0 cm off the waist.
2There is no validated dose conversion between them. Switchers restart tirzepatide low and titrate up.
3Guides say switch from one to the other, never take both.
4Tirzepatide activates GIP and GLP-1 receptors; semaglutide activates GLP-1 only. Online shorthand calls them GLP-2 and GLP-1 for that reason.
5SURMOUNT-5 (751 adults without diabetes, 72 weeks, open label, max tolerated doses): weight fell 20.2% on tirzepatide vs 13.7% on semaglutide 1.7 or 2.4 mg.
6In SURMOUNT-5, 64.6% on tirzepatide lost at least 15% vs 40.1% on semaglutide; waist shrank 18.4 cm vs 13.0 cm.
7SURPASS-2 (type 2 diabetes, 40 weeks): HbA1c fell 2.0, 2.2 and 2.3 points on tirzepatide 5, 10 and 15 mg vs 1.9 on semaglutide 1 mg.
8Do not take them together. The tirzepatide label says co-use with other GLP-1 drugs is not recommended.

Facts from each record, in the same words as their own pages.

Semaglutide and Tirzepatide side by side
	Semaglutide	Tirzepatide
Category	GLP-1, Weight loss	GLP-1, Weight loss
Evidence	Strong human trials	Strong human trials
FDA status	FDA approved as Ozempic +2Regulatory	FDA approved as Mounjaro +1Regulatory
WADA	Not prohibited	Not prohibited
Half-life	About 1 week. It is still present 5 to 7 weeks after the last dose.Regulatory	About 5 days (Mounjaro label); 5 to 6 days in people with obesity or sleep apnea (Zepbound label). That is why it is dosed once a week.Regulatory
Routes	Subcutaneous injection, Oral	Subcutaneous injection
Reported doses	0.125 to 7.2 mg (subcutaneous injection) 1.5 to 25 mg (oral) 300 to 1,000 mcg (subcutaneous injection)	0.25 to 15 mg (subcutaneous injection)
Most cited frequency	Once weekly; 4 weeks per step, then hold at 2.4 mg	Once weekly. Step up 2.5 mg after at least 4 weeks only if needed, then hold the maintenance dose.
Vial sizes	5 mg, 10 mg, 20 mg, 30 mgVendor guide	10 mg, 15 mg, 20 mg, 30 mg, 40 mg, 50 mg, 60 mgVendor guide
Mixed vial keeps	Keep the mixed vial in the fridge and use it within about 28 days; one guide says 30.Competitor guide	Keep the mixed vial in the fridge and use it within about 28 days.Competitor guide
Protocols on file	12	12

Doses shown are what sources report, labelled by origin. Not medical advice.

6 sources, each checked by date. Record updated Oct 23, 2026. Numbers are restated in our own words and labelled by where they came from.