Clinical Trial Evidence

Retatrutide Before and After: Weight-Loss Timeline and Results From the Clinical Trials

Last updated: August 6, 2026

Investigational medication Phase 3 research Not FDA-approved

What You Need to Know

The short version: retatrutide produced average weight loss of about 24% at roughly one year (Phase 2) and around 28–30% by two years at the highest dose (Phase 3), with weight coming off steadily rather than all at once.

24.2% Phase 2 · 48 weeks

28.3% Phase 3 · 80 weeks

30.3% Phase 3 · 104 weeks

45.3% Lost 30% or more

What "Before and After" Means for Retatrutide

Most "before and after" searches ask two things: how much weight do people lose, and how long does it take? Because retatrutide is investigational and not yet available by prescription, there is no library of verified patient photos — and anonymous photos online, often tied to unregulated products, aren't trustworthy evidence. What is trustworthy is the clinical-trial data, which is unusually strong for this drug.

Retatrutide Weight-Loss Timeline

Weeks 1–4

Small early loss

Starting dose (2 mg); appetite begins to change

Weeks 4–16

Steady, accelerating loss

Dose escalates through 4 mg and 8 mg

Weeks 16–24

Continued loss

Maintenance dose (9–12 mg) reached

~48 weeks (Phase 2)

~24% of body weight

Near one year, loss still ongoing

~80 weeks (Phase 3)

~28% (~70 lb)

Loss continuing toward plateau

~104 weeks (Phase 3)

~30% (~85 lb)

Approaching maximum effect

The scale keeps moving well past the first few months — judging retatrutide by week 8 badly underestimates it, because the dosing schedule means the dose isn't at maintenance yet.

What the Clinical Trials Show

Phase 2 obesity trial 24.2% Average body-weight loss 48 weeks · 12 mg dose

Phase 3 TRIUMPH-1 28.3% Average body-weight loss 80 weeks · approximately 70 lb

Phase 3 TRIUMPH-1 30.3% Average body-weight loss 104 weeks · approximately 85 lb

Key Phase 3 Finding 45.3%

of participants losing 30% or more — a degree previously associated mainly with bariatric surgery.

Phase 2 obesity trial (48 weeks): 12 mg dose lost an average of about 24.2% of body weight — the highest average for an obesity medication in a trial of its kind at the time.

Phase 3 TRIUMPH-1 (reported 2026): at 12 mg, roughly 28.3% at 80 weeks (~70 lb) and 30.3% at 104 weeks (~85 lb), with 45.3% of participants losing 30% or more — a degree previously associated mainly with bariatric surgery. Improvements were also reported in A1C, with signals in knee osteoarthritis pain and sleep apnea. These are averages; individual results vary.

What a Realistic "After" Looks Like

The big numbers are at the top dose over one to two years — a realistic personal result depends on the dose reached and how long treatment continues.

Early weeks are the slow part by design. During this period, understanding retatrutide side effects can help put the treatment timeline into context. Weight loss is not only fat — some is lean mass, so nutrition, resistance training, and adequate protein matter. And across this class, stopping treatment is generally followed by some regain, so durable results assume an ongoing plan.

Why Online "Before and After" Photos Aren't Reliable

Photos on social media and vendor sites are not verifiable, are frequently tied to unregulated products of unknown dose and quality, and can't be attributed to a known dose, duration, or supervision. The trial data — averages across hundreds of monitored participants — is a far more honest "before and after" than any individual image.

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Important Disclaimer

Retatrutide is investigational, not FDA-approved and not commercially available. Results here are averages from clinical trials, not guarantees of individual outcomes, for educational purposes only. Not medical advice.

Frequently Asked Questions

How much weight do you lose on retatrutide?

In trials, average loss at the highest dose was about 24% at ~1 year (Phase 2) and about 28–30% by 2 years (Phase 3). In Phase 3, 45.3% lost 30% or more. Individual results vary.

How long does it take to see results with retatrutide?

Gradual — the dose is titrated up over months. Small changes appear early, loss accelerates through weeks 4–16, and the largest reductions accumulate over one to two years.

Are retatrutide before-and-after photos online real?

They can't be verified — most are anonymous, often tied to unregulated products, and can't be linked to a known dose, duration, or supervision. Trial averages are far more reliable.

Is retatrutide weight loss better than tirzepatide or semaglutide?

In its trials, retatrutide has produced the highest average weight loss in the class so far — around 30% at two years at the top dose. Head-to-head trial data will ultimately confirm comparisons.

Will I regain the weight if I stop retatrutide?

Across the GLP-1 class, stopping is generally followed by some regain. Durable results assume an ongoing, supervised plan, and lifestyle plays a major role.