Search tirzepatide before and after and you get side-by-side photos. The published record is SURMOUNT-1: 2,539 adults, 72 weeks, and one endpoint measured on a scale.
The short answer. Tirzepatide: SURMOUNT-1 measured percent body-weight change in 2,539 adults over 72 weeks, not photographs.
- The top dose gave 22.5% on-treatment and 20.9% counting everyone randomized. Both figures are from the same trial.
- Reaching the 15 mg arm took about 20 weeks, so short-duration photos sit inside the titration period.
- The placebo arm lost 3.1% with lifestyle support, and gut side effects ran roughly 60\u201380% across the program.
Tirzepatide has real before-and-after data. SURMOUNT-1 ran 72 weeks in 2,539 adults. Mean weight loss at the top dose was 22.5%. That is a mean, not a promise. 57% lost 20% or more; others lost far less. The placebo arm lost 3.1% with lifestyle support. SURMOUNT-4 showed most of it returns after stopping.
What SURMOUNT-1 actually measured
The photograph is not the evidence. The evidence is SURMOUNT-1, published in the New England Journal of Medicine in 2022.
It randomized 2,539 adults with obesity across 119 sites in 9 countries. It ran 72 weeks. The endpoint was percent change in body weight.
- What was measured. Weight on a scale, and waist circumference. Percent change from baseline.
- What was not measured. Photographs. Skin tone, posture, lighting, or how a shirt fits.
- Arms. Tirzepatide 5, 10 or 15 mg once weekly, or placebo. Every arm began at 2.5 mg.
- Responder rates. 91% lost at least 5% of body weight. 57% lost at least 20%.
In this 72-week trial in participants with obesity, 5 mg, 10 mg, or 15 mg of tirzepatide once weekly provided substantial and sustained reductions in body weight.
Jastreboff et al., New England Journal of Medicine, 2022Those responder numbers are the useful part. A mean tells you about the group. The spread tells you that two people on the same dose can end up in very different photos.
Why you see both 22.5% and 20.9%
Two numbers circulate for the same trial arm. Both are correct. They answer different questions.
One counts everyone who was randomized, including people who quit the drug. The other counts people who stayed on it as assigned. Trial statisticians call these estimands.
| Weekly dose | On-treatment estimate | All randomized |
|---|---|---|
| 5 mg | −16.0% | −15.0% |
| 10 mg | −21.4% | −19.5% |
| 15 mg | −22.5% | −20.9% |
| Placebo | −2.4% | −3.1% |
Marketing quotes 22.5% because it is the larger figure. The number that includes everyone who dropped out is 20.9%. The honest read is that both belong to week 72, not to week 12.
Our tirzepatide complete guide carries the full trial set.
How long did the before and after take?
Longer than most captions admit. SURMOUNT-1 started every participant at 2.5 mg weekly. Steps up were 2.5 mg, about every four weeks.
Reaching the 15 mg arm took roughly 20 weeks. So the first five months of the trial were mostly climbing, not the top dose. The headline figure belongs to week 72.
That matters when you read a photo labeled "8 weeks" or "3 months." At that point in the trial, nobody was yet at the dose that produced the headline. What each arm received is set out in the tirzepatide dosage guide. We do not tell you what to take.
Tirzepatide
The compound discussed here, supplied as a research compound with a certificate of analysis matched to the lot.
What the photo leaves out
Three things, and all of them were measured.
Both arms got lifestyle support. Diet and activity counseling ran in the placebo group too. That group still lost 3.1% of body weight. Any before-and-after includes that baseline effect.
Gut side effects were common. In SURMOUNT-1, 33% reported nausea and 22% diarrhea. Vomiting hit 12%. Across the trials, gut complaints ran roughly 60–80%. About 4–7% stopped because of them. Most events were mild or moderate. Detail sits on the side effects page.
Body composition was not the endpoint. The trial reported weight and waist. A photo is a claim about what the weight was made of. SURMOUNT-1's primary measure does not answer that.
Stop the drug and the "after" moves
SURMOUNT-4, published in JAMA in 2024, is the trial that tests this directly. Everyone took tirzepatide for a 36-week lead-in. Mean weight loss by then was 20.9%.
Then people were split. Half kept the drug. Half switched to placebo. The study ran about 18 months in total.
- Continued treatment: ended at 25.3% total weight reduction.
- Switched to placebo: regained 14.0% of body weight, ending at 9.9%.
Withdrawing tirzepatide led to substantial regain of lost weight, whereas continued treatment maintained and augmented initial weight reduction.
Aronne et al., JAMA, 2024This is the single most important thing about a tirzepatide photograph. It is a snapshot of a person on the drug. It is not a snapshot of a finished process.
How it compares to the other before-and-afters
Trial means, side by side. These are different trials in different populations, so read them as scale, not as a race.
| Compound | Trial | Mean body-weight change |
|---|---|---|
| Retatrutide | Phase 2, 48 weeks | 24.2% |
| Tirzepatide | Phase III SURMOUNT-1 | 22.5% |
| Semaglutide | Phase III STEP-1 | about 15% |
There is also a true head-to-head, though it was in type 2 diabetes, not obesity. SURPASS-2 enrolled 1,879 adults. Tirzepatide's top dose gave 11.2 kg of weight loss against semaglutide's 5.7 kg, roughly 2×. HbA1c fell 2.30% versus 1.86%. See the tirzepatide vs semaglutide comparison.
One asymmetry is worth naming. Semaglutide has a completed cardiovascular outcomes trial, SELECT, in obesity without diabetes. Tirzepatide's outcomes trial, SURMOUNT-MMO, is still open. Weight is measured. Long-term event reduction, for tirzepatide, is not yet reported.
The research vial is not the approved drug
All of the above was generated with pharmaceutical-grade material, under trial supervision, in monitored patients. Tirzepatide is sold as Mounjaro for type 2 diabetes, approved in May 2022, and as Zepbound for obesity, approved in November 2023.
A research-use vial labeled "tirzepatide" is a different object. The approval status of the prescription product does not transfer to it. Identity and purity are only what a third-party document shows, which is why we keep a page on reading a certificate of analysis and one on legal status.
This site does not publish protocols for tirzepatide. We report what trials administered and what they measured. That is the whole of it.
Tirzepatide
Research-use-only material, sold by the vial with batch documentation. Check the certificate of analysis against the batch you receive.
What to know now
- SURMOUNT-1 measured percent body-weight change in 2,539 adults over 72 weeks, not photographs.
- The top dose gave 22.5% on-treatment and 20.9% counting everyone randomized. Both figures are from the same trial.
- Reaching the 15 mg arm took about 20 weeks, so short-duration photos sit inside the titration period.
- The placebo arm lost 3.1% with lifestyle support, and gut side effects ran roughly 60\u201380% across the program.
- SURMOUNT-4 found that switching to placebo brought back 14.0% of body weight, ending at 9.9% total loss.
What we're watching
If you want one thing to watch, look for a conference presentation of the SURMOUNT-4 withdrawal curve. The line goes down for 36 weeks, then splits. One branch keeps falling to 25.3%. The other climbs back to 9.9%. That split is the part a before-and-after photo cannot show.
Frequently asked questions
How much weight did people actually lose on tirzepatide in trials?
In SURMOUNT-1, the 15 mg arm lost 22.5% of body weight at 72 weeks on the on-treatment analysis, and 20.9% when everyone randomized is counted. The 10 mg arm was 21.4% and the 5 mg arm 16.0%. Placebo lost 2.4%. Those are means; 57% of participants lost at least 20% and 91% lost at least 5%.
How long does a tirzepatide before and after take?
The published figures belong to week 72. In SURMOUNT-1 every participant started at 2.5 mg weekly, with 2.5 mg steps about every four weeks, so reaching 15 mg took roughly 20 weeks. A photo labeled 8 or 12 weeks corresponds to a period when trial participants had not yet reached the top dose.
Do people regain the weight after stopping?
SURMOUNT-4 tested this. After a 36-week lead-in that reached 20.9% weight reduction, participants switched to placebo regained 14.0% of body weight and finished at 9.9%. Those who continued treatment reached 25.3%. The JAMA authors concluded that withdrawal led to substantial regain.
Is the weight loss fat or muscle?
SURMOUNT-1's endpoint was percent change in body weight, with waist circumference as a secondary measure. It was not designed as a body-composition study. So the trial record does not tell you what proportion of a given person's loss was fat versus lean tissue, which is exactly what a photograph implies.
Does tirzepatide beat semaglutide in the photos?
On weight, the head-to-head SURPASS-2 trial in 1,879 adults with type 2 diabetes found 11.2 kg on tirzepatide's top dose against 5.7 kg on semaglutide, about 2x. On long-term cardiovascular events, semaglutide has a completed outcomes trial and tirzepatide's SURMOUNT-MMO is still running.
Does this site publish a tirzepatide protocol?
No. We report what published trials administered and what they measured, attributed by name. We do not author doses, schedules or routes for tirzepatide, and the research-use vial does not inherit the approval status of Mounjaro or Zepbound.
What people actually report
These are self-reports, not evidence. No control group, no blinding, and no independent check that the vial held what the label claimed. They are collected here because people asking about Tirzepatide deserve an answer rather than a refusal, and because what the community believes is itself worth knowing. Quotes are excerpts; each links to the original post.
Uncontrolled, unverified self-report from people using prescribed compounded tirzepatide. Not a study, not a controlled sample. Across these threads posters describe loss measured in months and broken up by long stalls, not steady decline. Constipation is the effect raised most often: the poster opening the newbie thread names it as a worry before starting, and several repliers describe managing it. One replier in that thread lists two mild headaches, more burping after meals, and insomnia the night of the first dose, and says she never had any nausea at all. Multi-month stalls are treated as normal rather than failure, with posters describing plateaus of roughly two, three, four and almost five months. The dissent is specific: one poster reports reaching 15 mg, the maximum on Lilly's label, and losing zero pounds in eight months.
Where the community and the published record disagree. Lilly's US prescribing information for Zepbound sets a starting dose of 2.5 mg once weekly for four weeks, allows increases in 2.5 mg increments after at least four weeks on the current dose, lists maintenance dosages for weight reduction as 5 mg, 10 mg or 15 mg once weekly, and caps the maximum at 15 mg. These threads run on compounded tirzepatide dispensed by prescription, and posters describe schedules the label does not set out: split dosing every three days or every five days at the same weekly total, titrating up by 0.5 mg, and lowering a dose to break a stall. So label numbers are being used to vouch for a product and a schedule that label never set out. Note the community is large but not the largest: r/tirzepatidecompound has about 189,000 subscribers, while r/Zepbound (about 231,000) and r/Mounjaro (about 202,000) are bigger tirzepatide communities.
“I'm also worried about the side effects... particularly nausea and constipation.”
About to start on tirzepatide... what do you wish you knew before you started?
“I am in my 5th week of a plateau.”
“I have lost zero pounds in 8 months.”
“Discussing results and side effects is fine.”
“I'm sharing my experience losing weight using compounded Tirzepatide”
I Used Tirzepatide for 6 Months (Perimenopause Weight Loss Story)
“I receive a small commission from the product links above. I appreciate your support! This is not a sponsored video. All opinions are my own.”
My Tirzepatide Before And After | Mounjaro, Zepbound Results
“The recommended starting dosage of ZEPBOUND for all indications is 2.5 mg injected subcutaneously once weekly for 4 weeks.”
ZEPBOUND (tirzepatide) injection, for subcutaneous use - US Prescribing Information
Posts are quoted under fair use and linked to their authors. Nothing on this page is hosted here, and no claim above has been verified beyond confirming that the person wrote it.
References
- Jastreboff, A. M., Aronne, L. J., Ahmad, N. N., et al. (2022). Tirzepatide once weekly for the treatment of obesity. New England Journal of Medicine, 387(3), 205–216. https://doi.org/10.1056/NEJMoa2206038
- Aronne, L. J., Sattar, N., Horn, D. B., et al. (2024). Continued treatment with tirzepatide for maintenance of weight reduction in adults with obesity: The SURMOUNT-4 randomized clinical trial. JAMA, 331(1), 38–48. https://doi.org/10.1001/jama.2023.24945
- Frias, J. P., Davies, M. J., Rosenstock, J., et al. (2021). Tirzepatide versus semaglutide once weekly in patients with type 2 diabetes. New England Journal of Medicine, 385(6), 503–515. https://doi.org/10.1056/NEJMoa2107519
- Wilding, J. P. H., Batterham, R. L., Calanna, S., et al. (2021). Once-weekly semaglutide in adults with overweight or obesity (STEP-1). New England Journal of Medicine, 384(11), 989–1002. https://doi.org/10.1056/NEJMoa2032183
- Jastreboff, A. M., Kaplan, L. M., Frías, J. P., Wu, Q., Du, Y., Gurbuz, S., Coskun, T., Haupt, A., Milicevic, Z., & Hartman, M. L. (2023). Triple–hormone-receptor agonist retatrutide for obesity — A phase 2 trial. New England Journal of Medicine, 389(6), 514–526. https://doi.org/10.1056/NEJMoa2301972
- Lincoff, A. M., Brown-Frandsen, K., Colhoun, H. M., et al. (2023). Semaglutide and cardiovascular outcomes in obesity without diabetes. New England Journal of Medicine, 389(24), 2221–2232. https://doi.org/10.1056/NEJMoa2307563
- Melson, E., Ashraf, U., Papamargaritis, D., & Davies, M. J. (2024). What is the pipeline for future medications for obesity? International Journal of Obesity, 49(3), 433–451. https://doi.org/10.1038/s41366-024-01473-y