Retatrutide
Also called reta, LY3437943, triple G
Retatrutide is the newest and, so far, the most powerful of the GLP-1 weight-loss peptides.
Tested in large, properly controlled human trials. The ranges below are drawn from that trial data alongside what the community reports using.
148,640 posts38,936 people27 communities
of community reporting analysed for this compound. That is the part you cannot find anywhere else — the trial data below it, you could look up yourself.
- Belly fat / contouring
- Fat loss & metabolic
The quick answer
Retatrutide is the newest and, so far, the most powerful of the GLP-1 weight-loss peptides. What sets it apart is that it works on three fronts at once - quieting appetite, steadying blood sugar, and nudging up how many calories you burn at rest - where older drugs only do one.
People describe a consistent arc: in the first week the relentless "food noise" goes quiet and normal portions start to feel like too much, with the scale following over the next few weeks. It's a slow-and-steady tool, not an overnight one - you step the dose up gradually, and most people settle at a comfortable spot rather than chasing the ceiling. Start low, go slow, and let your appetite lead.
Why people use it
🔥 Serious, rapid weight loss; 🍽️ Kills the "food noise" and cravings; 📉 Steady fat loss, week after week; 🩸 Better blood sugar and insulin sensitivity; 🎯 Melts stubborn belly fat
What people report using
These are ranges other people have reported running. They are here so you can see what has actually been done — they are not medical advice and not a recommendation for you.
People report running this anywhere from 0.5mg to 6mg, once weekly.Where somebody sits in that range depends on what they are using it for and what they are starting from — the low end is a deliberate choice a lot of people make, not a half-hearted version of the high end.
Average body weight lost. This is the published answer to whether a small dose does anything — it does, and the table shows how much of the full effect it buys.
| 4mg | 19% | |
|---|---|---|
| 9mg | 25.9% | |
| 12mg | 28.3% |
Fat loss & metabolic
- How often
- Once weekly
- Route
- subcutaneous
- Where this comes from
- Large human trials
Fat loss & metabolic
- How often
- Once weekly
- Route
- subcutaneous
- Where this comes from
- Large human trials
Fat loss & metabolic
- How often
- Once weekly
- Route
- subcutaneous
- Where this comes from
- Community practice
Fat loss & metabolic
- How often
- Once weekly
- Route
- subcutaneous
- Where this comes from
- Large human trials
Fat loss & metabolic
- How often
- Once weekly
- Route
- subcutaneous
- Where this comes from
- Large human trials
Fat loss & metabolic
- How often
- Once weekly
- Route
- subcutaneous
- Where this comes from
- Large human trials
Fat loss & metabolic
- How often
- Once weekly
- Route
- subcutaneous
- Where this comes from
- Large human trials
Reconstitute to 10mg/ml (e.g. 30mg vial + 3ml BAC water). Titrate weekly: 2.5mg then 5mg then up to 8mg as tolerated. Once weekly.
Work out your own units on the reconstitution calculator — the most common serious mistake in this area is arithmetic, not chemistry.
What to expect, and when
- First thing people notice
- Days 1–7 (appetite)
- When it gets real
- Weeks 3–4 (scale movement)
- Where it peaks
- Months 3–6 (body composition)
- Patience needed
- High - weeks 1–4 are slow
- Days 1–3Appetite signal changes begin
Some people notice mild appetite reduction within 24–72 hours. Others feel nothing at all - both are normal. GLP-1 receptors are beginning to respond but plasma concentration at 2mg is still below full therapeutic range. Possible mild nausea, especially after large meals.
- Weeks 1–2Appetite suppression becomes noticeable (60% of users)
About 60% of users notice meaningful appetite suppression by week 2. Food doesn't sound as appealing. Portions satisfy sooner. The other 40% may feel very little - this is dose-dependent. 2mg is the tolerance-building dose, not the therapeutic dose. Don't judge the compound at this stage.
- Weeks 3–4Visible weight loss begins for most · scale starts moving
Week 3–4 is when most people first see meaningful scale movement. Appetite suppression is more consistent at 5mg. Early loss of 1–3kg is common - some water weight, some early fat. Cravings for sweet foods reduce measurably according to Phase 2 data.
- Weeks 5–8Acceleration phase · clothes fitting differently
Fat loss velocity increases as dose effect compounds. 4–7kg total loss is typical by week 8 for most users. The people around you start noticing around this phase. Clothes fit differently - often before the scale reflects the change. Blood sugar improvements are measurable.
- Months 3–6Major results · 10–20% body weight reduction typical
Phase 2 trial data shows 17.5% mean body weight reduction at 24 weeks at 12mg. At 5mg you'll see meaningful but less dramatic results. This is the sustained fat-loss window. Rate slows after month 3 but continues. Blood pressure, cholesterol, and liver markers improve alongside body composition.
Week 4 is the most common dropout point. People have endured nausea, spent money, and lost primarily water weight. Clinical data shows 8–12% of early discontinuations happen here. Those who persist to week 8 consistently report dramatically better results. Don't judge Retatrutide at week 4.
Side effects, and what people do about them
The golden rule here is simple: go slow with the dose. As the most powerful of the GLP-1s, it can bring some nausea or digestive changes if you ramp up too fast - a patient, gradual increase keeps most people comfortable. Keep eating well and staying hydrated. If you have a personal or family history of thyroid cancer or pancreatitis, have a quick word with your doctor before starting. Take it slow and it's very manageable.
Go deeper
Open these only if you want them.
How it actually works
Triple agonist - GLP-1, GIP and the glucagon receptor. The first two quiet appetite and steady blood sugar; the third is what nothing else in common use has, and it raises energy expenditure rather than only reducing intake. That third arm is the mechanistic reason the trial results sit above the dual and single agonists.
For stacking, the arithmetic is simple and frequently ignored. Semaglutide is GLP-1 alone. Tirzepatide is GLP-1 plus GIP. Both are already inside this molecule, so adding either is stacking the same receptors and collecting both discomfort profiles for the appetite effect of whichever is stronger. Cagrilintide is the pairing that adds something, because amylin is a receptor none of these touch.
What people report, in full
Retatrutide still has the most consistent feedback of anything on this list. Appetite quietens within the first few days and the scale usually follows by about week four. Two things have shifted in what people report since July. First, plenty of people now split the weekly amount across two days - most often Monday and Thursday - because appetite creeps back around day four or five; the people doing it say the week feels more even, others say the single larger shot is what makes the difference, and there is no agreement either way. Second, the community titrates more slowly than the trials did, often starting well under the trial's opening amount and holding each step six to eight weeks instead of four. The stated aim is the lowest amount that still works rather than the highest tolerated. On stopping, the hope is usually a small maintenance amount; most people who report back say they needed something close to what they lost on.
Sources and review
Most of what is useful about these compounds comes from people who have used them, not from trials. These are published analyses of what communities reported. We did not read the posts ourselves and we do not claim to.
148,640 posts38,936 people27 communities
Reports from 2021-05-01 to 2025-12-31
Sehgal NKR, Tronieri JS, Rader B, Ungar L, Guntuku SC. Self-Reported Side Effects Among Reddit Users Taking Unapproved Retatrutide. medRxiv 2026.
Preprint. Authors state explicitly they cannot estimate incidence, causality, dose-response or product purity. These are proportions of people who posted, not of people who used.
Jastreboff AM et al. Triple–Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. N Engl J Med 2023. DOI 10.1056/NEJMoa2301972. PMID 37366315. Registered NCT04881760.Source of the 48-week dose-response figures held on this record, including the 1mg arm at 8.7% of body weight against 2.1% on placebo. This is the published evidence that a low dose does something. Citation attached 15 Sep 2026; the abstract could not be fetched at the time, so the figures remain as researched rather than re-verified against the paper — a human should confirm them before they are treated as checked.
Last reviewed 2026-09-06.
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