GGLP1 Base

Wegovy vs Zepbound

Wegovy and Zepbound are the two FDA-approved weight-management GLP-1 medications. They are not the same molecule. Here is what the data shows.

FieldWegovyZepbound
Active ingredientSemaglutideTirzepatide
Receptors activatedGLP-1GIP + GLP-1 (dual)
ManufacturerNovo NordiskEli Lilly
Maximum dose2.4 mg weekly15 mg weekly
Titration steps5 steps over 16 weeks6 steps over 20 weeks
Avg weight loss in trials~15% at 68 weeks~20% at 72 weeks
List price (US)~$1,350/month~$1,060/month (or via LillyDirect)

The head-to-head trial

SURMOUNT-5 was the first direct head-to-head trial between tirzepatide and semaglutide for weight management. At 72 weeks, tirzepatide produced an average weight reduction of about 20% versus about 14% for semaglutide. About one-third of tirzepatide patients lost 25% or more of starting body weight, versus around 16% on semaglutide. Tolerability profiles were broadly similar.

Cost and access

Zepbound's list price is lower than Wegovy's, and Lilly's LillyDirect program offers single-dose vials at a further reduced cost for self-pay patients. Both face periodic supply constraints, though semaglutide shortages have been more publicized in recent years.

Choosing between them

Average data favors Zepbound for weight loss magnitude. Individual variation is substantial — some patients respond better to one than the other, and side-effect tolerability can decide it for some. Insurance coverage is often the practical determining factor.