Semaglutide and tirzepatide are the two main drugs behind the GLP-1 medication boom. They work similarly but have one important difference.
Quick Comparison
| Semaglutide | Tirzepatide | |
|---|---|---|
| Drug class | GLP-1 agonist | Dual GIP/GLP-1 agonist |
| Brand names | Ozempic, Wegovy, Rybelsus | Mounjaro, Zepbound |
| Makers | Novo Nordisk | Eli Lilly |
| Injection | Once weekly | Once weekly |
| Oral option | Yes (Rybelsus) | No |
How They Work
Semaglutide mimics one hormone: GLP-1. This hormone tells your brain you're full and slows your stomach.
Tirzepatide mimics two hormones: GLP-1 and GIP. Two signals instead of one. That extra hormone may be why some people see stronger results.
Weight Loss Results
From clinical trials:
- Semaglutide (Wegovy 2.4 mg): ~15% body weight loss
- Tirzepatide (Zepbound 15 mg): ~21% body weight loss
Tirzepatide shows higher average weight loss. But these were separate trials, not direct comparisons. Your body may respond differently.
Side Effects
Both cause similar side effects:
- Nausea (most common)
- Diarrhea or constipation
- Decreased appetite
- Vomiting (less common)
- Stomach pain
- Fatigue
Side effects are usually worst when you start and after each dose increase. Most people adjust within a few weeks.
Brand Names to Know
Semaglutide comes as:
- Ozempic (diabetes)
- Wegovy (weight loss)
- Rybelsus (oral pill for diabetes)
Tirzepatide comes as:
- Mounjaro (diabetes)
- Zepbound (weight loss)
Cost
Both cost around $1,000-1,350/month without insurance. Your actual cost depends on your insurance coverage and any savings cards.
Who Should Choose Semaglutide?
- You want the option of an oral pill (Rybelsus)
- You've used it before and it works
- Your insurance covers it
- You prefer a medication with a longer track record
Who Should Choose Tirzepatide?
- You want the option of higher average weight loss
- You tried semaglutide and didn't get enough results
- Your insurance covers it
- Your doctor recommends it
Bottom Line
Tirzepatide uses two hormones and tends to produce more weight loss. Semaglutide uses one hormone and has been around longer with an oral option.
The best choice depends on your insurance, your health history, and what your doctor recommends.
Work with your healthcare provider to determine which medication is right for you. Individual results and experiences vary.