Zepbound Results: What to Expect at 1, 3, 6 and 12 Months
In SURMOUNT-1, people on tirzepatide 15 mg weekly lost 20.9% of their body weight on average over 72 weeks, against 3.1% on placebo.
- Average loss, top dose
- 20.9%
- On placebo
- 3.1%
- Trial length
- 72 weeks
- Trial
- SURMOUNT-1
Zepbound: the basics
Its half-life is 5 to 6 days. After 5.5 d, half is gone; after five half-lives (27.5 d), about 3% remains.
At 72 weeks, SURMOUNT-1 reported 20.9% of body weight, compared with 3.1% on placebo.
In US dollars, monthly prices include the list price and self-pay offers. Each comes from the maker's price page.
Sources: FDA label (DailyMed), Eli Lilly 1 2, cnbc.com.
Zepbound results: the numbers first
| 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 with type 2 diabetes who had obesity or overweight |
| SURMOUNT-2 | Tirzepatide 15 mg weekly | 14.7% | 3.2% | 72 | Adults with type 2 diabetes who had obesity or overweight |
| SURMOUNT-5 | Tirzepatide 10 or 15 mg weekly (Zepbound) | 20.2% | semaglutide (Wegovy) | 72 | Adults with obesity, without type 2 diabetes |
Sources for each trial: SURMOUNT-1 (FDA label (DailyMed)), SURMOUNT-2 (PubMed), SURMOUNT-5 (PubMed).
Understanding the average in pounds
For the 20.9% trial average, researchers used three starting weights. This is only arithmetic, not a prediction for one person: some lose more, while 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 |
Cited here: FDA label at DailyMed.
Details by Week
- During the first weeks, stomach side effects occur most often while your dose remains low and then increases. After every dose increase, these effects often return for a few days.
- SURMOUNT-1 reached its end at Week 72, when the average loss above was recorded.
Sources: health.clevelandclinic.org, FDA label at DailyMed.
Why it stalls and what helps
- See where you are in the dose steps. Every trial listed above showed less weight loss at the lower doses.
- Over the last month, count the doses you missed or took late.
- Keep a record of what you eat and drink for a few days. When portions shrink, calories from drinks and grazing add up.
- Talk with your prescriber about thyroid or blood sugar testing. If progress has stalled for months, ask about switching medicines too.