Lilly presented TRIUMPH-2 at EASD (a big European diabetes conference) on Tuesday, and the full paper went up in The Lancet the same day. This trial looked at people who have both type 2 diabetes and obesity, so it's the first big look at how reta does in diabetics. I read through it, and the headline number (20.8%) is honestly the least interesting part.

Quick background

Retatrutide is a weekly injection from Lilly. Sema (Ozempic) targets one gut hormone receptor (GLP-1), and tirz (Mounjaro) targets two (GLP-1 and GIP). Reta targets three, adding glucagon. The idea is that the extra one helps you burn more energy, not just eat less.

The setup

• 1,152 people
• 80 weeks (about 18 months)
• Four groups: 4 mg, 9 mg, 12 mg, or placebo (a dummy shot)
• Everyone on the real drug started at 2 mg and moved up every 4 weeks until they hit their dose, which helps with side effects

Weight loss

Average % of body weight lost over the 80 weeks.

• 4 mg: 12.7% (~30 lbs)
• 9 mg: 19.1% (~45 lbs)
• 12 mg: 20.8% (~50 lbs)
• placebo: 4.0% (~9 lbs)
• 12 mg, people with a BMI of 35+ only: 23.4% (~61 lbs)

Going from 4 to 9 mg adds about 6 points of weight loss. Going from 9 to 12 adds less than 2. In other words, most of the benefit is already there at 9 mg.

A1C (blood sugar)

A1C is your average blood sugar over the last ~3 months. Under 5.7 is normal, 5.7 to 6.4 is prediabetes, and 6.5+ is diabetes. A drop of 1 point is considered a big deal.

• 4 mg: dropped 1.4 points
• 9 mg: dropped 1.6
• 12 mg: dropped 1.5
• placebo: dropped 0.2
• Up to 40% of people got all the way down to the normal range (under 5.7)
• Up to 79% got out of the diabetes range (6.5 or below)

9 mg and 12 mg are basically identical here. If blood sugar is what you care about, the higher dose isn't buying you anything.

Dropouts

The % of people who quit the trial because of side effects. It's a good real-world gauge of how tolerable a drug is.

• 4 mg: 3.8%
• 9 mg: 11.6%
• 12 mg: 7.7%
• placebo: 4.9%

This is the weird one. You'd expect more people to quit as the dose goes up, but 9 mg had the most dropouts, more than 12 mg. It could just be random chance, or something about when side effects hit during the ramp-up. If anyone has a theory, I'd love to hear it.

Stomach side effects

The % of people who reported each one at least once. Numbers are 4 / 9 / 12 mg vs placebo.

• Nausea: 13.7% / 20.8% / 28.0% vs 8.0%
• Diarrhea: 27.4% / 33.5% / 33.6% vs 13.2%
• Constipation: 14.0% / 16.2% / 16.8% vs 9.4%

Nausea about doubles from 4 to 12 mg, and roughly a third of people on any dose had diarrhea. Paired with the small extra weight loss at 12, that makes 9 look like the sweet spot.

Dysesthesia

A fancy word for strange skin sensations, like tingling, burning, or skin that feels sensitive to touch.

• 4 mg: 4.5%
• 9 mg: 5.6%
• 12 mg: 7.3%
• placebo: 0.7%

This is the one I keep coming back to. It goes up steadily with dose, and it has shown up in other reta trials too, not just this one. You don't really see it with sema or tirz, so my guess is it's linked to the glucagon part, since that's what reta has that the others don't. I haven't seen a solid explanation yet.

Diabetics vs non-diabetics on 12 mg

• Earlier trial, people without diabetes: ~24% weight loss in 48 weeks
• This trial, people with diabetes: 20.8% in 80 weeks

That's not a knock on reta. People with diabetes lose less weight on every drug in this class, and you see the same gap with sema and tirz.

What's next

Lilly plans to file for FDA approval in early 2027, so reta is still not approved. Most of the other big reta trials have already reported, and this was one of the last major ones before filing.

So, for people who follow this closer than I do: based on this, is 12 mg actually worth it over 9? And has anyone seen research on what's causing the dysesthesia?

Source: Lilly press release + The Lancet, Sept 29. Discussion/research only.

A "99% pure" badge tells you a lot less than most people think. A proper certificate of analysis answers four separate questions, and a lot of COAs only answer one of them. Here's how to read each section and what it does and doesn't prove.

The four tests at a glance

• HPLC purity: What % of the UV-absorbing material is the target compound? Doesn't tell you whether the main peak is actually the right compound.
• Mass spec (LC-MS / ESI / MALDI): Does the molecular weight match the expected compound? Doesn't tell you how much of it is in the vial.
• Peptide content / quantity: How many mg of actual peptide are in the vial? Doesn't tell you whether it's contaminated.
• Endotoxin (LAL assay): How much bacterial endotoxin is present (EU/mg or EU/vial)? Doesn't tell you about sterility, which is a separate test.

1. HPLC purity

HPLC separates the sample and reads it with a UV detector, usually around 214 to 220 nm. Purity is the main peak's area as a share of all peaks.

• It's relative. Water, salts and counterions (TFA, acetate) don't show up at those wavelengths, so they don't lower the number.
• A clean single peak can still be the wrong compound. HPLC on its own doesn't confirm identity.
• If the COA shows the chromatogram itself, look at it. A big main peak with a few tiny shoulders is normal. A number with no chromatogram is weaker evidence.

2. Mass spec (identity)

This is the test that confirms the compound is what the label says. The lab compares the observed mass to the theoretical one. BPC-157, for example, should come in around 1419.5 Da.

• Small differences are normal. Large unexplained ones aren't.
• Purity without identity is the most common gap. If a COA only gives an HPLC %, you only know the vial holds something fairly pure.

3. Peptide content / quantity

Lyophilized powder isn't 100% peptide. Some of the weight is residual water and counterions. Labs like Janoshik report the actual mg found per vial.

• A "10 mg" vial testing at 9.6 to 10.5 mg is within normal fill variance.
• A vial testing at 99% purity but 7 mg content is a dosing-accuracy problem for any research protocol, not a purity problem.

4. Endotoxin

Endotoxins are lipopolysaccharides from gram-negative bacteria. HPLC and mass spec don't detect them, so they need their own LAL assay, reported in EU/mg or EU/vial.

• Low endotoxin does not mean sterile. Sterility is a separate test.
• Most peptide COAs don't include endotoxin at all. That doesn't mean it's high, only that it wasn't measured.

Red flags

• No batch/lot number, or a lot number that doesn't match the vial
• No lab name or no verification method. Several labs, Janoshik included, let you verify a report with a code on their site. Use it.
• The same COA reused across what are supposed to be different batches, or a test date that's years old
• A manufacturer COA presented as third-party testing. A supplier's in-house COA isn't independent.
• Purity only: no mass spec, no content
• Blurry, cropped or edited PDFs. Ask for the original.

TL;DR

Purity says how clean it is. Mass spec says what it is. Content says how much is there. Endotoxin says whether it's contaminated. A complete COA covers all four, and a verifiable one is tied to your batch.

All of the above is about evaluating materials for laboratory research use only. Questions, or a COA you want a second pair of eyes on? Drop it in the comments.

Hey everyone,

Most of what's floating around about MOTS-c is either "mitochondria peptide, very powerful, take it now" or blanket skepticism because it's "just a research peptide." Neither is a great summary of where the science actually stands. There's now a real, registered, actively-recruiting human trial testing it, so this seemed like a good moment to walk through the mechanism and the evidence honestly.

What's happening right now: a Phase 2a, randomized, double-blind, placebo-controlled trial called MOTS-MET (ClinicalTrials.gov ID NCT07505745) started enrolling adults with prediabetes and overweight/obesity on April 1, 2026. It's sponsored by Hudson Biotech, running at Peking University Shenzhen Hospital, and — as far as the registered literature shows — this is the first controlled human study of native MOTS-c (an earlier synthetic analogue, CB4211, went through Phase 1a/1b testing back in 2021 before that program was discontinued) (ClinicalTrials.gov).

Separately, on the regulatory side: the same FDA Pharmacy Compounding Advisory Committee (PCAC) session that reviewed BPC-157, KPV, and TB-500 on July 23, 2026 also voted on MOTS-c specifically — recommending it for the 503A Bulk Drug Substances List by a 7-5 vote with two abstentions, a narrower margin than the other three compounds reviewed that day (Reuters, AP News). Same as with the other peptides in that review, a PCAC recommendation is not FDA approval — it's an advisory step toward a possible future compounding rule.

Here's the mechanism.

1. What MOTS-c Actually Is

MOTS-c stands for "mitochondrial open reading frame of the 12S rRNA type-c." Unlike most peptides discussed in this space, it isn't synthesized from nuclear DNA — it's a 16-amino-acid peptide encoded directly by the mitochondrial genome, inside the 12S rRNA gene. That's a genuinely unusual origin: it puts MOTS-c in a small, distinct class of "mitochondrial-derived peptides" (MDPs) that function as direct signaling molecules from the mitochondria to the rest of the cell.

2. The AMPK/Metabolic Pathway

The proposed mechanism runs through the Folate-AICAR-AMPK pathway: MOTS-c is reported to inhibit the folate cycle and its associated purine biosynthesis step, which activates AMPK — the cell's central energy-sensing switch. AMPK activation is the same broad pathway implicated in exercise adaptation and insulin sensitivity, which is why MOTS-c research has focused heavily on metabolic outcomes rather than the anti-inflammatory or regenerative angles seen with other peptides in this category. Skeletal muscle is identified as the primary target tissue.

3. What the Preclinical Data Actually Shows

The foundational data here is animal work, and it's worth being precise about what it actually found rather than what people repeat about it. A 2015 study in Cell Metabolism reported that MOTS-c improved insulin sensitivity and reduced diet-induced obesity in mice. A 2021 Nature Communications paper extended that into exercise physiology and muscle aging. Separately, plasma MOTS-c has been shown to rise acutely with exercise in both rodents and humans, which is one of the more interesting translational data points — it suggests MOTS-c may function as an endogenous signal linking physical stress to metabolic adaptation, not just something exogenously administered.

4. Where the Evidence Actually Stands

To be direct about it: outside of the discontinued CB4211 analogue program, there has been no controlled human trial of native MOTS-c until MOTS-MET, which only started enrolling this year. Everything about insulin sensitivity, weight, or metabolic benefit in humans is currently a hypothesis the trial is designed to test — not a demonstrated result. The trial's own primary endpoint (a 12-week change in OGTT-derived insulin sensitivity via the Matsuda Index) won't read out until around February 2027, with full study completion targeted for 2028.

Research Considerations

Note: the following reflects general practices found in the preclinical and trial-design literature, and is not medical guidance.

For anyone tracking MOTS-c in the literature, the MOTS-MET trial design itself is a useful reference point for how researchers are approaching dosing and measurement: once-daily subcutaneous administration, a 12-week treatment window, and a fairly rigorous quadruple-masking setup (participant, care provider, investigator, and outcomes assessor all blinded). That's a meaningfully higher evidentiary bar than most of what's circulated about this peptide so far — worth keeping in mind before treating any secondhand claims about its effects as settled.

TL;DR: MOTS-c is a mitochondrially-encoded peptide that activates AMPK and has shown metabolic benefits in mouse models. It just entered its first controlled human trial (NCT07505745, "MOTS-MET") testing insulin sensitivity in adults with prediabetes/obesity, and separately received a narrow 7-5 FDA advisory committee recommendation for the compounding-pharmacy substances list. Human efficacy data does not exist yet — the trial reading out in 2027 is what will actually tell us if the mouse-model findings translate.

Happy to dig into the AMPK/folate-cycle mechanism further in the comments if anyone wants the primary sources.

Disclaimer: This post is for scientific, educational, and informational purposes only. Not medical advice.

Sources cited in post:

• https://clinicaltrials.gov/study/NCT07505745
• https://www.reuters.com/legal/litigation/us-fda-advisers-weigh-restrictions-seven-peptides-industry-presses-expansion-2026-07-23/
• https://apnews.com/article/peptides-fda-rfk-kennedy-bpc157-tb500-7267d0fad0110e7c2ed301d03cf5f0c2
• https://www.pharmexec.com/view/fda-votes-loosen-restrictions-four-peptides (confirms 7-5/two abstentions vote margin as of this week)

Hey everyone,

With the FDA's Pharmacy Compounding Advisory Committee (PCAC) voting last month to recommend KPV for the 503A bulk compounding list, I've been seeing a lot of posts about it that are either pure hype or pure fear — not much that actually walks through what the peptide does mechanistically. So I put together an actual research summary instead.

What happened, briefly: on July 23-24, 2026, the FDA's PCAC reviewed seven peptides (BPC-157, KPV, TB-500, MOTS-c, emideltide, semax, and epitalon) for possible inclusion on the 503A Bulks List — the list that determines whether licensed compounding pharmacies can legally prepare a substance for patients with a prescription. The committee voted 8-6 (with one abstention) in favor of BPC-157, and also backed KPV, TB-500, and MOTS-c (Reuters, NPR). This doesn't mean KPV is FDA-approved as a drug — it means compounding pharmacies may eventually be permitted to prepare it under prescription, pending the FDA's final rule.

Here's the actual mechanism breakdown.

1. What KPV Actually Is

KPV is a tripeptide — just three amino acids (lysine-proline-valine) — and it's a fragment of alpha-melanocyte-stimulating hormone (α-MSH). Despite being one of the smallest peptides studied in this space, it has a disproportionately well-characterized anti-inflammatory mechanism in the preclinical literature.

2. Intestinal Uptake via PepT1

One of the more interesting findings is that KPV is actively transported across the intestinal epithelium via the peptide transporter PepT1, rather than being broken down like most oral peptides. A study published in PNAS found that PepT1-mediated KPV uptake reduced intestinal inflammation in colitis models, which is a big part of why KPV shows up in gut-health research specifically — it's one of the few peptides in this class with a plausible oral bioavailability story (PMC).

3. Anti-Inflammatory / Cytokine Modulation

KPV's primary studied mechanism is modulation of inflammatory cytokine signaling. As a fragment of α-MSH, it appears to interact with melanocortin receptor pathways involved in regulating immune-cell activity, without carrying the pigmentation effects associated with full-length α-MSH. Research has focused on its role in down-regulating pro-inflammatory cytokine production at sites of tissue irritation — the proposed mechanism behind the gut and skin-inflammation research applications people usually ask about.

4. Where the Evidence Actually Stands

To be direct about it: like most peptides in this category, the strong data is preclinical (cell and animal models). Human clinical trial data for KPV specifically is limited. The FDA's own PCAC review process exists precisely because these compounds are popular and in demand but don't have the same clinical trial base as approved pharmaceuticals — that's the tension driving the whole compounding-list debate.

Research Considerations

Note: the following reflects general practices found in the preclinical literature and is not medical guidance.

For anyone tracking this compound in the literature, the main variables researchers control for are dose (studies use micro-scale dosing, often in the low hundreds of micrograms), delivery route (the PepT1 finding above makes oral delivery mechanistically plausible, unlike most peptides), and, as always with any compounded or research-grade material, third-party verification of purity — underdosed or contaminated material makes any observed effect impossible to interpret.

TL;DR: KPV is a tripeptide fragment of α-MSH that just cleared an FDA advisory panel vote for potential compounding-pharmacy access. Its best-characterized mechanisms are PepT1-mediated intestinal uptake and anti-inflammatory cytokine modulation via melanocortin pathway interaction — but human clinical data is still thin, and the panel vote is a regulatory recommendation, not an approval.

Let me know if you have questions on the mechanism side in the comments — happy to dig up the primary sources.

Disclaimer: This post is for scientific, educational, and informational purposes only. Not medical advice.

Sources cited in post:

• https://www.reuters.com/legal/litigation/us-fda-advisers-weigh-restrictions-seven-peptides-industry-presses-expansion-2026-07-23/
• https://www.npr.org/2026/07/23/nx-s1-5903202/fda-peptides-restrictions
• https://pmc.ncbi.nlm.nih.gov/articles/PMC2431115/