Retatrutide is the triple agonist — it hits three hormone receptors (GLP-1, GIP and glucagon) instead of one or two — and it has produced the biggest weight-loss numbers the obesity field has ever seen from a drug. In the Phase 3 TRIUMPH-1 trial reported in 2026, the highest dose produced an average 28.3% body-weight reduction (about 70 lbs) over 80 weeks.
But there are no real “before and after” selfies to show you, and anyone posting them should make you suspicious: retatrutide is still investigational and not approved anywhere. The honest before-and-after is the trial data. Here is exactly what it shows — and the caveats that the transformation photos never mention.
What “before and after” really means here
Type “retatrutide before and after” into a search bar and you will find transformation photos, forum logs and influencer threads. Treat them with caution. Retatrutide has not been approved by Health Canada, the FDA or any other regulator — it is an investigational drug still moving through trials. That means there is no legitimate prescription supply, and any “after” photo is either from a clinical trial participant or from someone using an unregulated, unverified source.
So the only trustworthy before-and-after is the data from the trials themselves, where thousands of people were measured under controlled conditions. Fortunately, that data is remarkable on its own — you do not need the selfies.
The Phase 2 numbers
Retatrutide first turned heads with its Phase 2 trial, published in the New England Journal of Medicine in 2023. Adults with obesity lost an average of up to 24.2% of their body weight at the highest dose over 48 weeks. For context, that was already beating the averages seen with tirzepatide and semaglutide, and it was only Phase 2.
The results were also dose-dependent: higher doses produced more loss, and the weight-loss curve had not clearly flattened by the end of the study — hinting there was more to come with longer treatment.
The Phase 2 curve was still heading downward at 48 weeks. That single detail is why the obesity world held its breath for the Phase 3 readout.Why retatrutide became the most-watched molecule in the field
The Phase 3 TRIUMPH-1 numbers
The wait ended in 2026. The Phase 3 TRIUMPH-1 trial delivered the headline the field expected: at the highest dose, participants lost an average of 28.3% of their body weight — about 70.3 lbs — over 80 weeks. The trial tested three once-weekly doses (4 mg, 9 mg and 12 mg) against placebo.
Those numbers push into territory that used to belong only to bariatric surgery. The trial also reported improvements in participants who had obstructive sleep apnea and knee osteoarthritis — less knee pain and fewer sleep disturbances — which matters because obesity rarely travels alone.
| Trial | Dose | Avg weight loss | Duration |
|---|---|---|---|
| TRIUMPH-1 (Phase 3) | 12 mg weekly | ~28.3% (~70 lbs) | 80 weeks |
| Phase 2 (NEJM 2023) | 12 mg weekly | up to ~24.2% | 48 weeks |
These are the doses the published trials used, reported as trial facts — not a protocol and not guidance. Retatrutide is not available by prescription, so there is no “how to take it” to give.
What the curve looks like over time
The one thing the before-and-after photos get most wrong is time. Nobody loses 28% of their body weight in a month. In the trials the loss built gradually over many months as the dose was slowly increased, with the steepest drop in the first half and a flattening toward the end. A realistic mental model is a long, steady slope — not a switch. People who expect an overnight transformation are the ones who get discouraged and quit early.
How it compares to Ozempic and Mounjaro
Retatrutide’s trial averages are the highest of the modern obesity drugs:
| Drug | Receptors | Avg weight loss (trial) |
|---|---|---|
| Retatrutide | GLP-1 + GIP + glucagon | ~28% (Phase 3) |
| Tirzepatide (Mounjaro/Zepbound) | GLP-1 + GIP | ~21% |
| Semaglutide (Ozempic/Wegovy) | GLP-1 | ~15% |
The pattern is almost poetic: one receptor, two receptors, three receptors — and the weight loss climbs with each. For the full lineup see retatrutide vs tirzepatide vs semaglutide and the next weight-loss drugs after Ozempic.
The catches nobody photographs
- It is not approved. As of 2026 retatrutide is investigational. There is no legal prescription supply and no quality-controlled consumer product.
- Side effects are real. Like other incretin drugs, the trials reported mostly gastrointestinal effects — nausea, vomiting, diarrhoea — concentrated during dose increases. See retatrutide side effects.
- The weight comes back. With this drug class, stopping typically leads to substantial regain. The “after” is not self-sustaining.
- Averages hide individuals. A 28% average means some lost far more and some far less. Your mileage would genuinely vary.
- Muscle matters. Rapid loss this large includes lean mass; protecting muscle is part of doing it well. See muscle loss on GLP-1 drugs.
Retatrutide is an investigational drug, not approved for use in people. The figures here are published clinical-trial results reported for information only — not an endorsement, not a protocol, and not dosing guidance. Weight-management decisions belong with your doctor.
The research-compound angle
Retatrutide is sold in the research-peptide market — at TrueLabs it is listed as RT3. This is a raw compound for in vitro and laboratory study, not the trial drug and not a medicine. It has no verified human dose, no sterile drug formulation and no regulatory approval. The impressive trial numbers above describe the pharmaceutical-grade molecule used under medical supervision in a study — they are not a promise about a research vial. If your work is in metabolic research, see is retatrutide approved? and how to read a peptide COA.
Retatrutide before-and-after myths
“Myth: Those before-and-after photos are typical results.”
Posted photos are cherry-picked and unverifiable, and the drug is not legally available. Trust the trial averages, not a thread.
“Myth: You will lose 28% no matter what.”
28% is an average at the highest dose over 80 weeks. Individuals ranged widely, and results depend on dose, duration and the person.
“Myth: The results are permanent.”
Stopping incretin drugs usually brings substantial regain. The maintenance phase is the hard part the photos skip.
“Myth: Research retatrutide gives the same before-and-after.”
A research compound is not the trial drug — no verified dose, formulation or oversight. The trial data does not transfer to an unapproved vial.
For researchers
TrueLabs supplies retatrutide as RT3 from $90, tirzepatide as TZ-2 from $73, and Cagrilintide from $40, in CAD for in vitro and laboratory research only. Before ordering, see how to read a peptide COA and the COA library.
FAQ
Tap a question to reveal the answer.
How much weight did people lose on retatrutide?
In the Phase 3 TRIUMPH-1 trial, the highest dose (12 mg weekly) produced an average 28.3% body-weight reduction, about 70 lbs, over 80 weeks. Phase 2 had shown up to about 24.2% over 48 weeks.
Are retatrutide before-and-after photos real?
Be skeptical. Retatrutide is not approved or legally available, so any photo is from a trial participant or an unregulated source. The reliable before-and-after is the trial data.
How long does it take to see retatrutide results?
In trials, weight came off gradually over many months as the dose was raised, steepest early and flattening later. It is a long slope, not an overnight change.
Is retatrutide better than Ozempic and Mounjaro?
On trial averages, yes — about 28% versus roughly 21% for tirzepatide and 15% for semaglutide. It is the most potent of the three on weight, but still investigational.
Is retatrutide approved?
No. As of 2026 it is investigational and not approved by Health Canada, the FDA or other regulators. There is no legal prescription supply.
Does the weight come back after stopping?
Typically yes. As with other incretin drugs, stopping tends to cause substantial regain, so the results are not self-sustaining.
What are the side effects?
Trials reported mainly gastrointestinal effects — nausea, vomiting and diarrhoea — concentrated during dose increases. See our retatrutide side effects guide.
Is research retatrutide the same as the trial drug?
No. Research retatrutide such as TrueLabs RT3 is a raw compound for lab use, without a verified dose, drug formulation or approval. The trial numbers describe the pharmaceutical molecule, not a research vial.
Related reading
- Retatrutide vs tirzepatide vs semaglutide
- Retatrutide side effects
- Is retatrutide approved?
- Next weight-loss drugs after Ozempic
- Muscle loss on GLP-1 drugs
References
- Jastreboff AM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. N Engl J Med. 2023;389(6):514-526. NEJM
- Eli Lilly / American Diabetes Association. TRIUMPH-1 Phase 3 retatrutide results, 2026. Lilly
- Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022;387:205-216. NEJM
- Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP-1). N Engl J Med. 2021;384:989-1002. NEJM
This article summarizes published research and regulatory information for information only and is not medical advice. TrueLabs research compounds are sold for in vitro and laboratory research use only and are not intended for human or veterinary use.