Retatrutide Before and After: What TRIUMPH-1 Actually Showed

Patients searching “retatrutide before and after” almost always want two things: photos of someone who took the drug, and a sense of what kind of transformation is realistic. We don't post patient photos or stock transformation imagery because those don't generalize and they aren't evidence. What does generalize, with appropriate caveats, is the magnitude reported in the pivotal trial. TRIUMPH-1 (NCT05929066, n=2,339) was presented at the 86th American Diabetes Association Scientific Sessions in May 2026 [1][2][8]. On the 12 mg dose at 80 weeks, mean total body-weight reduction was -28.3% (about 70.3 lbs lost). The BMI-35-or-higher extension cohort reached -30.3% (about 85.0 lbs lost) at 104 weeks. That is the largest mean weight loss any pharmacological obesity therapy has ever produced in a Phase 3 trial — and it approaches the magnitude historically associated with bariatric surgery. Below: the dose-response, the responder rates, side-by-side comparisons to Wegovy / Zepbound / Foundayo, and honest framing for what to expect in real-world (non-trial) use.

The honest short answer

Retatrutide 12 mg at 80 weeks produced -28.3% mean total body weight reduction in TRIUMPH-1 — the first pivotal Phase 3 readout in adults with obesity [1]. The 104-week extension in the BMI 35+ cohort reached -30.3% TBWL (-85.0 lbs). Placebo lost 2.2%. To put this in plain language: a 250 lb patient who responded at the trial mean would weigh roughly 179 lbs at 80 weeks on the 12 mg dose, or 174 lbs in the extension cohort. The 4 mg starter dose produced -19.0% TBWL — itself larger than what Wegovy 2.4 mg produced at 68 weeks in STEP-1 [6]. This is the largest pharmacological obesity result on record and it changes the framing of what a “before and after” can mean.

What TRIUMPH-1 actually showed

TRIUMPH-1 (NCT05929066) randomized 2,339 adults with obesity (or overweight plus weight-related comorbidity, no type 2 diabetes) to retatrutide 4 mg, 9 mg, 12 mg, or placebo, all once weekly subcutaneously, with the primary endpoint at 80 weeks [1][2]. A pre-specified extension out to 104 weeks enrolled the subset of patients with baseline BMI 35 or higher. The TRIUMPH master design (including TRIUMPH-1, -2, -3 and -4) was published by Giblin et al. in Diabetes, Obesity and Metabolism in 2026 [3]. Verified topline numbers from the May 2026 Eli Lilly press release and the ADA 86th Scientific Sessions late-breaking symposium [1][8]:

The placebo arm lost 2.2% — consistent with the lifestyle intervention common to all GLP-1 pivotal trials (modest caloric reduction plus increased physical activity counseling). That baseline lets us isolate the drug-attributable effect at each dose: about -16.8 percentage points at 4 mg, -23.7 at 9 mg, -26.1 at 12 mg, and -28.1 in the 104-week extension.

Dose-response: 4 mg / 9 mg / 12 mg transformation magnitudes

The dose-response in TRIUMPH-1 is monotonic but compressed at the top — the same shape we saw in the SURMOUNT-1 tirzepatide trial [5] and the retatrutide Phase 2 trial. Each step up adds roughly 7 additional percentage points of weight loss, with diminishing returns between 9 and 12 mg:

• 4 mg starter dose: -19.0% mean TBWL at 80 weeks. By itself this is larger than the highest dose of Wegovy in STEP-1 (-14.9% at 68 weeks) [6] and very close to Zepbound 15 mg in SURMOUNT-1 (-20.9% at 72 weeks) [5]. The retatrutide starter dose is roughly the ceiling of the previous best-in-class drug.
• 9 mg middle dose: -25.9% TBWL at 80 weeks. This is the dose most patients are expected to tolerate, and it already exceeds every approved GLP-1 single-agent and dual-agonist by a meaningful margin.
• 12 mg top dose: -28.3% TBWL at 80 weeks; -30.3% in the 104-week BMI 35+ extension. The 12 mg dose is what generates the “before and after” transformations that approach bariatric-surgery magnitudes, but it also carries the highest GI adverse event rate (per the consistent class pattern; full TRIUMPH-1 adverse event tables will follow with the peer-reviewed publication).

What ≥30% body-weight loss actually means clinically

TRIUMPH-1 reported 45.3% of patients on 12 mg hit at least 30% body-weight reduction [1]. That threshold matters because it puts retatrutide responders in the same effect-size neighborhood as bariatric surgery. In the STAMPEDE 5-year RCT (Schauer 2017 NEJM) of patients with type 2 diabetes and a mean baseline BMI of about 37, Roux-en-Y gastric bypass produced -23% mean body-weight reduction and sleeve gastrectomy produced -19% at 5 years [10]. The 10-year SLEEVEPASS RCT in patients with higher baseline BMI converts to roughly 22-24% TBWL for bypass and sleeve. Both surgeries are irreversible and carry surgical morbidity plus a permanent need for vitamin and protein supplementation. Retatrutide produces overlapping magnitude with a reversible, non-surgical, self-administered weekly injection.

The other framing-shift comes from the BMI categorical outcome: 65.3% of 12 mg patients reached BMI below 30, meaning they no longer met the WHO obesity threshold at the end of the trial. That is the largest published rate of obesity reversal for any pharmacological therapy.

Waist circumference and responder rates

Lilly reported mean waist circumference reduction of 9.5 inches (about 24 cm) at the 12 mg dose [1]. Waist circumference change is a clinically useful outcome separately from TBWL because it tracks visceral fat loss specifically, which is the adipose depot most strongly linked to cardiometabolic risk.

Responder-rate categories are how trials communicate “your chance of hitting threshold X.” The verified TRIUMPH-1 12 mg rates [1]:

• 45.3% achieved at least 30% body-weight reduction (the bariatric-surgery-overlap zone)
• 65.3% achieved a BMI below 30 (no longer clinically obese)

For comparison, SURMOUNT-1 tirzepatide 15 mg reported about 57% of patients hit at least 20% TBWL [5]. STEP-1 semaglutide 2.4 mg reported about 32% hit at least 20% [6]. Retatrutide 12 mg shifts the entire distribution rightward — the 30% threshold becomes achievable for nearly half the trial population.

How TRIUMPH-1 compares to Wegovy, Zepbound, and Foundayo

The most useful “before and after” mental model is a side-by-side comparison of approved-drug magnitudes, because most patients have either tried or considered Wegovy, Zepbound, or Foundayo before they encounter retatrutide:

Retatrutide's 28.3% at 80 weeks is roughly 1.9x larger than Wegovy, 1.4x larger than Zepbound, and 2.5x larger than Foundayo at each drug's respective pivotal endpoint. For deeper trial-by-trial analysis, see our Wegovy vs Ozempic evidence review and our tirzepatide vs semaglutide head-to-head.

Real-world expectations vs trial mean

Pivotal-trial populations are not typical real-world patient populations. Trial participants get free drug, free clinic visits, monthly lifestyle counseling, structured titration support, and they enrolled because they were motivated enough to commit to 80-104 weeks of weekly injections plus scheduled study visits. Real-world patients miss doses, pause for vacations or supply gaps, manage side effects without on-call clinic support, and often discontinue prematurely.

Published real-world data for the GLP-1 class come in well below pivotal-trial means. In a Cleveland Clinic electronic-health-record cohort of 3,389 adults treated with injectable semaglutide or liraglutide, 1-year mean total body-weight loss on semaglutide prescribed for obesity was 5.9% — versus 17.3% in STEP 1, or roughly one-third of the pivotal mean (Gasoyan 2024 JAMA Netw Open, PMID 39269703) [11]. Among patients with persistent medication coverage (cumulative gap under 90 days at 1 year), the mean was 5.5%; among those with under 90 days of coverage, only 1.8% [11]. Applied to retatrutide 12 mg, that evidence-based real-world expectation is in the roughly 9-14% TBWL range at 80 weeks for the average patient, with the most adherent subset approaching 14-17%. Patients who discontinue early regain much of their loss: the STEP 1 trial extension (Wilding 2022, PMID 35441470) reported that one year after stopping weekly semaglutide 2.4 mg, participants regained roughly two-thirds of their prior weight loss, with net loss falling from 17.3% on treatment to 5.6% at week 120 [9]. SURMOUNT-4 (tirzepatide withdrawal) showed a more modest regain pattern. There is no reason to expect retatrutide will behave differently in this regard, and patients should plan on long-term — not time-limited — therapy.

Why we don't post patient photos

Three reasons we anchor this article on numeric magnitude rather than visual before-and-after imagery:

1. Photos don't generalize. Any specific patient's transformation reflects their starting BMI, body composition, dose tolerated, adherence, baseline diet, baseline activity level, and underlying medical comorbidities. The trial mean is statistical, not aesthetic.
2. Stock-photo before-and-afters are usually fake. The same models appear in promotions for unrelated weight-loss products. Using them implies patient-specific results we cannot verify.
3. YMYL editorial standard. For your-money-or-your-life health content, the responsible framing is verified primary-source magnitude with appropriate caveats, not visual marketing that bypasses the citation chain.

If you want to see what a 28% or 30% body-weight loss looks like on your own frame, the most honest tool is a body-weight calculation, not a stranger's photo: multiply your current weight by 0.717 (for -28.3%) or by 0.697 (for -30.3%) and compare to the BMI categorical line for your height.

When will retatrutide be available?

As of May 2026, Eli Lilly has not yet filed the New Drug Application (NDA) for retatrutide and has not announced a US brand name [1]. The standard FDA review timeline for a priority-review NDA is 6-10 months from filing; standard review is 10-12 months. Conservative timing from the TRIUMPH-1 readout to commercial availability is roughly12-18 months post-NDA-filing, putting likely US availability somewhere in 2027 depending on when the NDA is submitted and whether priority review is granted.

For tracking the FDA-filing and label-content milestones, plus the broader pipeline (CagriSema, MariTide, survodutide, Ecnoglutide), see our GLP-1 trial results quarterly and the access-timeline companion retatrutide approval and access timeline. For the foundational triple-agonist mechanism deep-dive and the Phase 2 (Jastreboff 2023 NEJM) data, see our retatrutide triple agonist evidence review. For the verified safety signal profile from the TRIUMPH program, see the retatrutide side-effects comprehensive evidence article. For the broader lipid-and-metabolite secondary profile published by Pearson et al. in JCEM May 2026, see citation [4] below.

Side-by-side magnitude chart