Semaglutide vs tirzepatide at a glance
| Compared | Semaglutide | Tirzepatide |
|---|---|---|
| Brand names | Ozempic, Wegovy, Rybelsus | Mounjaro, Zepbound |
| Maker | Novo Nordisk | Eli Lilly |
| Hormones copied | GLP-1 | GIP and GLP-1 |
| How it’s taken | Weekly injection or daily pill | Weekly injection |
| Weight loss in its main trial | 14.9% at 68 weeks | 20.9% at 72 weeks |
| Head to head (SURMOUNT-5) | 13.7% at 72 weeks | 20.2% at 72 weeks |
| Approved for | Type 2 diabetes, weight, heart risk, kidney disease, MASH | Type 2 diabetes, weight, sleep apnea |
Which causes more weight loss?
Tirzepatide, on average. In SURMOUNT-5, the only large head-to-head trial, adults with obesity lost 20.2% of their body weight on tirzepatide versus 13.7% on semaglutide after 72 weeks, and lost more from their waist.
Individual results vary a lot, and some people lose more on semaglutide.
Why is tirzepatide stronger?
Tirzepatide acts on two hormone receptors, GIP and GLP-1, while semaglutide acts on GLP-1 alone. Researchers think the added GIP effect improves appetite control and how the body handles fat and sugar.
How do the side effects compare?
Both mostly cause stomach side effects: nausea, diarrhea, vomiting and constipation, usually while the dose is going up. Both carry the same boxed warning about thyroid C-cell tumors seen in rodents and the same warnings about pancreatitis and gallbladder problems.
Which is cheaper?
Both have US list prices over a thousand dollars a month before insurance. Both makers now sell lower cash-pay options (Zepbound vials, and Novo Nordisk’s self-pay programs), and Canada approved generic semaglutide in 2026.
Which has more approved uses?
Semaglutide has more. Beyond diabetes and weight, it is approved to lower heart attack and stroke risk, to protect the kidneys in people with type 2 diabetes, and for the fatty liver disease MASH; tirzepatide is also approved for obstructive sleep apnea.
Where does retatrutide fit?
Retatrutide adds a third target, the glucagon receptor, and produced 28.3% average weight loss at 80 weeks in the TRIUMPH-1 trial. It isn’t approved yet, and Eli Lilly plans to apply in 2027.