Mounjaro Timeline: Week by Week, What Changes and When
SURMOUNT-1 ran 72 weeks. By the end, people on tirzepatide 15 mg weekly had lost 20.9% of their body weight on average, against 3.1% on placebo. Side effects are most common in the first weeks and after each dose increase.
- Average loss, top dose
- 20.9%
- On placebo
- 3.1%
- Trial length
- 72 weeks
- Trial
- SURMOUNT-1
A quick overview of Mounjaro
With a half-life of about 5 days, half disappears after 5 d. After five half-lives (25 d), about 3% remains.
In SURPASS-1, people with type 2 diabetes lost 7.8 kg over 40 weeks. The placebo group lost 1 kg.
The maker's price page provides monthly list price and self-pay offers in US dollars.
Sources: FDA label (DailyMed), healthsystemtracker.org, pricinginfo.lilly.com.
Mounjaro timeline: the numbers first
Blood sugar was the main focus when Mounjaro was tested. The same medicine is sold as Zepbound. The weight trials shown here used a higher dose of it.
| Trial | Dose group | Average weight lost | Placebo or comparison | Weeks | Who was in it |
|---|---|---|---|---|---|
| SURMOUNT-1 | Tirzepatide 5 mg weekly | 15% | 3.1% | 72 | Adults with obesity or overweight, without diabetes |
| SURMOUNT-1 | Tirzepatide 10 mg weekly | 19.5% | 3.1% | 72 | Adults with obesity or overweight, without diabetes |
| SURMOUNT-1 | Tirzepatide 15 mg weekly | 20.9% | 3.1% | 72 | Adults with obesity or overweight, without diabetes |
| SURMOUNT-2 | Tirzepatide 10 mg weekly | 12.8% | 3.2% | 72 | Adults who had obesity or overweight together with type 2 diabetes |
| SURMOUNT-2 | Tirzepatide 15 mg weekly | 14.7% | 3.2% | 72 | Adults who had obesity or overweight together with type 2 diabetes |
Sources: SURMOUNT-1 (FDA label (DailyMed)), SURMOUNT-2 (PubMed).
How the average works out in pounds
The trial average was 20.9% when applied to three starting weights. The number reflects arithmetic, not a forecast for any one person. Some people lose more, and others lose less.
| Starting weight | Average loss on tirzepatide 15 mg weekly | Average loss on placebo |
|---|---|---|
| 180 lb | about 38 lb | about 6 lb |
| 220 lb | about 46 lb | about 7 lb |
| 260 lb | about 54 lb | about 8 lb |
Sources: FDA label (DailyMed).
Week by week
- Stomach side effects occur most often at first, when the dose is low and rising. After every dose increase, these side effects often come back for a few days.
- SURMOUNT-1 closed at Week 72. The average loss listed above was measured at that point.
The two references are health.clevelandclinic.org and the FDA label (DailyMed).