Semaglutide vs retatrutide at a glance
| Compared | Semaglutide | Retatrutide |
|---|---|---|
| Brands | Wegovy, Ozempic, Rybelsus | None yet |
| Maker | Novo Nordisk | Eli Lilly |
| Hormones copied | GLP-1 | GLP-1, GIP and glucagon |
| Weight loss in main trial | 14.9% at 68 weeks (STEP 1) | 28.3% at 80 weeks (TRIUMPH-1) |
| Status | FDA-approved | Investigational; filing planned for 2027 |
| How it’s taken | Weekly injection or daily pill | Weekly injection |
How do semaglutide and retatrutide work differently?
Semaglutide copies one gut hormone, GLP-1, while retatrutide copies three: GLP-1, GIP and glucagon. The glucagon part is thought to raise the energy the body burns, on top of the appetite effects of the other two.
Which causes more weight loss?
Retatrutide did in its trials: 28.3% average weight loss at 80 weeks in TRIUMPH-1, compared with 14.9% at 68 weeks for semaglutide in STEP 1. The trials were different, so the numbers aren’t a direct comparison.
Tirzepatide, which copies two hormones, sits between them; see semaglutide vs tirzepatide.
How do the side effects compare?
Both mainly cause stomach side effects, especially while the dose is being raised. Retatrutide trials also reported dysesthesia, a tingling or burning skin feeling that mostly settled during treatment.
Semaglutide’s long-term risks are better known because it has been used by millions of people; retatrutide’s aren’t fully known yet.
Can you get retatrutide legally?
Not outside a clinical trial. Semaglutide is available by prescription, while products sold online as “retatrutide” are unapproved research chemicals that nobody checks.
Each drug’s page lists its dosing with sources: label doses for semaglutide, trial doses for retatrutide.