Retatrutide + MOTS-c + Tesamorelin
Three compounds at three completely different stages of proof.
Retatrutide has five positive Phase 3 trials and no approval. Tesamorelin has an approval, for a condition almost nobody in this stack has, and targets fat retatrutide already strips hard. MOTS-c has never completed a human efficacy trial, and its first one reports in 2027.
Three angles at once, and the most complex stack on this site.
The logic is that each compound covers something the others do not. Retatrutide takes weight off generally. Tesamorelin targets visceral fat, the deep kind packed around the organs that ordinary weight loss reaches last. MOTS-c is added for energy through a long calorie deficit, since eating substantially less for months leaves people flat and training badly.
It is also the stack most often paired with a recommendation for medical supervision, and the reasons are specific rather than general. Several members influence blood sugar and they do not all push the same way.
Three evidence states in one vial set.
Five positive Phase 3 trials, the final and largest stage of drug testing. TRIUMPH-1 produced 28.3% average weight loss over 80 weeks in 2,339 adults, the largest result anyone has published. A US filing is planned for early 2027. Approved nowhere yet.[1]
FDA approved in 2010 for reducing excess abdominal fat in adults with HIV-associated lipodystrophy, a condition where body fat moves into an unusual pattern. Pooled across 806 participants, visceral fat fell about 15.4% against placebo, meaning a dummy injection with nothing active in it, which came to roughly one kilogram and two centimetres of waist.[2]
No completed human trial has shown it does anything. The first efficacy trial began on 2 February 2026 and reports around February 2027. Until then the case rests on mouse and rat work.[3]
Those three columns hold the argument for and against this stack in one place. One compound is doing the heavy lifting with real evidence. One is doing a narrower job with real but modest evidence in a different population. One has not been tested for effect in people at all.
Tesamorelin is added for a job retatrutide already does.
The case for tesamorelin here is that it goes after visceral fat specifically. That argument was built against a plain GLP-1, and it holds much less well against retatrutide.
The reason is the third receptor. Switching on the glucagon receptor drives fat out of the liver and the abdominal cavity specifically, and it is what separates retatrutide from tirzepatide and semaglutide.
A smaller study running inside the main trial measured it. In people with fatty liver disease, retatrutide cut liver fat by 81.4% at one dose and 82.4% at the next, against a 0.3% increase on placebo. At the top dose, 86% of participants finished with liver fat in the normal range. On placebo, not one participant did.[4]
So the compound added to reach visceral fat is being added to the one compound that already strips it hardest. The two-compound version of this stack covers that in full. Nobody has tested whether tesamorelin adds anything measurable on top.
Three compounds moving blood sugar in different directions.
This is why the supervision advice attaches to this stack specifically. It is not a general caution.
One compound pushing blood sugar down, one pushing it up, and one whose effect is the subject of an unfinished trial. Nobody has measured what happens when all three run together, and if something goes wrong there is no way to attribute it to any one of them without stopping everything.
That is the practical argument for running fewer compounds at once, and it applies here more sharply than anywhere else on this site.
The compound doing the work is the one you will feel.
In TRIUMPH-1 at the top dose, against a placebo group: nausea in 42.4% against 14.8%, diarrhoea 32.0% against 13.5%, constipation 26.1% against 10.9%, vomiting 25.3% against 4.8%. About 11.3% stopped because of side effects, against 4.9% on placebo.[6]
Heart rate rose by around 6.7 beats per minute at the top dose, higher than tirzepatide or semaglutide produce, and that traces to the glucagon receptor retatrutide adds.[6] Most of the stomach and gut effects appear in the first week or two after each dose increase and settle over about four to six weeks.
Adding two compounds with smaller or unmeasured effects does not change any of that, and one of the two works against retatrutide's blood sugar benefit while doing it.
Every compound you remove here has a case for removing it.
Most stacks on this site get worse when you strip them back. This one is unusual because the evidence points the other way at every step.
Drop MOTS-c and you are left with retatrutide and tesamorelin, removing the compound that has never completed a human efficacy trial and saving about $28. The trial that would justify keeping it reports in 2027.
Drop tesamorelin too and you have retatrutide alone, which carries every bit of the evidence on this page. Five positive Phase 3 trials, 28.3% average weight loss, and no second compound working against its blood sugar benefit. That also removes about $20 and the reason the supervision advice attaches.
The case for keeping either addition rests on mechanism reasoning that nobody has tested. The case for dropping them rests on the fact that the compound doing the work has been tested five times and worked every time.
What people ask about this stack
Is the three-compound version better than the two?
Nobody has measured either version, so there is no evidence to compare. What can be said is that the third compound, MOTS-c, has never completed a human efficacy trial, and that the second, tesamorelin, targets fat retatrutide already attacks hard through its glucagon receptor activity. The strongest evidence on this page belongs to retatrutide taken on its own.
Why does this stack come with supervision advice?
Because of blood sugar specifically. Retatrutide lowers it, cutting A1C by 1.4 to 1.6 points in adults with type 2 diabetes. Tesamorelin raises it, and its label says to consider stopping if blood sugar problems develop. MOTS-c's direction is unknown and is the primary outcome of a trial still running. Running all three leaves no way to attribute a problem to any one of them.
Does tesamorelin help with belly fat here?
On its own it does, modestly. Pooled across two Phase 3 trials of 806 participants, visceral fat fell about 15.4% against placebo, which came to roughly one kilogram and two centimetres of waist. The effect also reverses within about 24 weeks of stopping. Whether it adds anything on top of retatrutide, which cut liver fat by more than 80% in its own substudy, has never been tested.
What does MOTS-c contribute?
Unknown. It has never completed a human efficacy trial. The first one, a study in adults with prediabetes, meaning blood sugar that is high but not yet diabetic, and excess weight, began on 2 February 2026 and reports around February 2027. The animal work on metabolism is consistent and the human work is correlational. The semaglutide version of this pairing covers it in detail.
What does it cost?
About $80 for one vial of each at the cheapest single-compound listings we track, which makes it the most expensive stack on this site. Roughly $48 of that buys the two compounds whose contribution on top of retatrutide has never been measured. Compare against the other stacks.
Is any of it approved?
Only tesamorelin, and only for reducing excess abdominal fat in adults with HIV-associated lipodystrophy. Retatrutide is approved by no regulator anywhere, with a US filing planned for the first quarter of 2027. MOTS-c has no approval and no classification on the compounding list at all.
What this page is built on
- 01Retatrutide Phase 3 programme. TRIUMPH-1 NCT05929066, 2,339 adults over 80 weeks, 28.3% at the top dose. TRIUMPH-2 in type 2 diabetes, A1C down 1.4 to 1.6 points from 7.7%. US filing planned for the first quarter of 2027.
- 02Falutz et al., the Phase 3 trials that supported tesamorelin's approval. Pooled analysis of 806 participants, visceral adipose tissue reduced approximately 15.4% against placebo at 26 weeks. New England Journal of Medicine report of the same programme at DOI 10.1056/NEJMoa072375. Plus the payer assessment covering the roughly 2 cm waist change, reversal within about 24 weeks of stopping, and rises in fasting glucose and A1C.
- 03MOTS-MET, Phase 2a in adults with prediabetes and overweight or obesity. Hudson Biotech. NCT07505745. Started 2 February 2026, primary completion estimated 14 February 2027. Plus an evidence review noting no completed published human efficacy trials and recommending baseline bloodwork.
- 04Randomised phase 2a substudy of retatrutide in metabolic dysfunction-associated steatotic liver disease, 98 participants. PMC11271400. Liver fat change at 24 weeks: minus 81.4% at 8 mg, minus 82.4% at 12 mg, plus 0.3% on placebo.
- 05Peptide Decoding vendor pricing data, 13 September 2026. Lowest in-stock single-compound listings: retatrutide $32.48, MOTS-c $27.55, tesamorelin $20.00.
- 06TRIUMPH-1 adverse event figures against placebo, and the roughly 6.7 bpm heart rate rise at the top dose with its onset and settling pattern.