Tirzepatide vs semaglutide: which is better for weight loss?

Both tirzepatide and semaglutide are once-weekly subcutaneous injectable peptides used for weight management and type 2 diabetes. The core difference is mechanism. Semaglutide is a GLP-1 receptor agonist, so it acts on a single hormone pathway. Tirzepatide is a dual GIP and GLP-1 receptor agonist, so it acts on two. That second pathway is the main reason researchers expected, and then measured, a difference in average results.

In the SURMOUNT-5 trial (New England Journal of Medicine, 2025), the first major head-to-head comparison, tirzepatide produced greater average weight loss than semaglutide: roughly 20% of body weight versus roughly 14% over about 72 weeks. Important caveat: those are trial averages. Real results vary by person, dose, diet, and activity, and no one can promise you a number. Which medication is right for you is a decision to make with a licensed provider.

The first two columns hold the contrast that matters most. The third column (the full semaglutide detail) is hidden on small screens to keep the table readable.

Both medications mimic hormones your gut releases after you eat, which helps regulate appetite, slow how fast your stomach empties, and support blood-sugar control. The difference is how many of those hormone signals each one taps into.

• Semaglutide targets the GLP-1 receptor. It is sold as Ozempic and Rybelsus (approved for type 2 diabetes) and Wegovy (approved for weight management), all made by Novo Nordisk.
• Tirzepatide targets both the GIP and the GLP-1 receptors. It is sold as Mounjaro (type 2 diabetes) and Zepbound (weight management), both made by Eli Lilly.

If you want the full mechanism in plain language, we wrote it up here: how tirzepatide works.

A lot of the confusion is just naming. The same drug shows up under different brand names depending on whether it is approved for diabetes or for weight management.

• Ozempic and Rybelsus: semaglutide, for type 2 diabetes.
• Wegovy: semaglutide, for weight management.
• Mounjaro: tirzepatide, for type 2 diabetes.
• Zepbound: tirzepatide, for weight management.

So “tirzepatide vs Ozempic” is really tirzepatide vs semaglutide, just phrased through one of semaglutide's brand names.

For both medications, the most common side effects are gastrointestinal: nausea and similar digestive symptoms. They are usually most noticeable when the dose increases, which is one reason both are started low and stepped up gradually on an increasing-dose plan rather than begun at full strength. Both require a provider's evaluation before you start, and both are prescription-only.

This page is general education, not a substitute for that evaluation. A licensed provider weighs your health history against the known risks and benefits of each medication.

Crossing offers compounded tirzepatide (not semaglutide). It is compounded with vitamin B6, manufactured by BPI Labs (an FDA-registered 503B facility in Largo, Florida, operating under cGMP), and dispensed by The Pharmacy Hub, a licensed 503A pharmacy. To start, you complete a roughly 10-minute online visit. If a provider licensed in your state determines it is appropriate, your medication ships to you.

See the tirzepatide product details, the full tirzepatide cost breakdown, or our provider-by-provider comparison.