Studies & sources

This review explains why SS-31 was designed and how it targets mitochondria via cardiolipin. It is a useful overview of the science, but it summarizes existing work rather than proving the peptide works in people.

Adults with obesity and sleep apnea had far fewer breathing interruptions per hour of sleep on tirzepatide than on placebo.

In people with fatty liver and obesity, retatrutide dramatically reduced fat in the liver as measured by MRI.

A 2024 review that ties the science together: it explains how the drug builds protective pigment and notes the evidence is strong for EPP but still early and unproven for other skin conditions.

In this tiny but important Barth syndrome study, SS-31 did not beat placebo in the strictly controlled phase. Over years of open-label use, patients improved on walking and heart measures, but without a comparison group those later gains are harder to trust. This program nonetheless supported the drug's 2025 accelerated approval for Barth syndrome.

For dry macular degeneration, SS-31 did not improve vision or slow the main measure of retinal damage compared to placebo. There was a hint it might protect photoreceptor structure, but that is an indirect marker, not proven vision benefit.

Researchers reanalyzed the failed mitochondrial myopathy trial and found that one genetic subgroup may have benefited. This is a clue, not proof, and a new dedicated trial was launched to test it properly.

In a large heart-disease trial, people on semaglutide had 20% fewer major cardiovascular events than people on placebo over about 3 years.

In a mid-stage trial, adults with obesity lost roughly a quarter of their body weight on the highest dose of retatrutide over about a year.

In adults with type 2 diabetes, retatrutide produced large drops in HbA1c and substantial weight loss in a Phase 2 trial.

In the largest and most rigorous trial of SS-31 for inherited muscle mitochondrial disease, the peptide failed to beat placebo on walking distance or fatigue, which were the main goals. It was safe, but it did not work for the trial population as a whole.

Adults with obesity lost about a fifth of their body weight on tirzepatide over 72 weeks, vs. ~3% on placebo.

Adults with overweight or obesity lost an average of about 15% of their body weight on weekly semaglutide over 68 weeks, vs. about 2.4% on placebo.

In a head-to-head trial in type 2 diabetes, tirzepatide lowered blood sugar and weight more than semaglutide 1 mg.

Recreational runners on NMN showed slightly better aerobic capacity after 6 weeks than the placebo group.

This was the large, rigorous test of the popular idea that oxytocin could help autistic children socially. Published in a top medical journal, it found no meaningful benefit over placebo. It is the most important reason to be skeptical of oxytocin sprays for autism.

Hospitalized severe COVID-19 patients who received thymosin alpha-1 had lower mortality than matched comparison patients.

This EMA-mandated 'does it work in the real clinic?' study found that EPP patients on afamelanotide spent more time outdoors and felt better, with less painful sun reactions. As an uncontrolled study it adds confirmation rather than definitive proof.

Over three years in a Swiss group of EPP patients, the time they could stay in direct sun before burning jumped from about 10 minutes to about 3 hours, pain dropped, and almost everyone kept up with treatment. It is real-world evidence, not a controlled trial.

In a head-to-head trial, semaglutide lowered blood sugar and weight more than another GLP-1 drug, liraglutide.

In the FDA pivotal trials, premenopausal women with low sexual desire saw improvements on PT-141 compared with placebo, with nausea as the main side effect.

A review of how PT-141 is used and how it compares to other treatments for low sexual desire.

Older adults who took NR raised their NAD+ levels and some inflammation markers improved, but insulin sensitivity didn't budge.

Oral NR raised NAD+ levels and was well tolerated for 8 weeks in adults with overweight.

MOTS-c-treated mice ran longer on a treadmill and showed muscle gene changes that looked like a trained state.

Drug-like NNMT blockers (the class 5-Amino-1MQ belongs to) reduced body fat in obese mice, but the work stops at rodents.

This analysis combined many smaller trials testing whether oxytocin nasal spray improves social understanding in people with neurodevelopmental conditions. The overall result was underwhelming—little to no benefit for most measures—reinforcing that these uses remain unproven.

The FDA accepted that AOD-9604 was safe enough to be used as a food ingredient — not the same as approving it as a drug.

On a brain scan, kisspeptin increased activity in sexual and bonding-related brain areas in young men.

A broad review of how GHK-Cu affects skin repair, with emphasis on topical and cosmetic uses.

In mice, MOTS-c kept insulin working better as the animals aged or gained weight.

People with anxiety disorders showed changes in a brain-growth protein (BDNF) after using Selank.

In IVF, kisspeptin successfully triggered eggs to mature with apparently lower risk of a dangerous overstimulation syndrome.

The pivotal trials: in two well-controlled studies totaling 168 EPP patients, the afamelanotide implant let people spend significantly more time in the sun without pain and improved their quality of life, with side effects that were generally manageable. This is the evidence that led to drug approval.

A large real-world look at 115 EPP patients found that quality of life roughly doubled after starting the implant and stayed high over years, with only minor side effects. Because there was no control group, it supports—rather than proves—benefit.

This review took a hard, skeptical look at all the 'oxytocin makes you trusting' research and concluded the effect is not dependable. It is the honest counterweight to the 2005 study and explains why claims about oxytocin and social behavior should be treated cautiously.

In a dish, tendon cells exposed to BPC-157 made more growth-hormone receptors — which the authors suggest could help tendons respond to repair signals.

An eye-drop version of the parent protein helped dry-eye symptoms in a small trial — but this isn't the same as the injected TB-500 used in recovery circles.

After bowel surgery, patients on ipamorelin recovered gut function faster than patients on placebo.

In a small trial, topical LL-37 helped leg ulcers heal better than placebo.

When researchers lowered NNMT activity in mouse fat and liver, the mice gained much less fat on a high-fat diet even though they ate the same amount.

When tested carefully, the MGF peptide did nothing measurable to muscle cells in the dish — a key counterweight showing the muscle-building claims for MGF are far from proven.

One of the only human trials touching ipamorelin — in surgery recovery, not muscle building, and not in combination with CJC-1295.

Component evidence for the ipamorelin half — tested in surgery recovery, not fat loss, and not alongside tesamorelin.

In animals with experimentally damaged hearts, thymosin beta-4 helped protect heart cells and improve recovery.

Adults with HIV-related belly-fat accumulation lost a meaningful amount of internal fat and liver fat on tesamorelin.

Older adults with cognitive concerns on tesamorelin scored better on tests of planning and memory than the placebo group.

A review that takes MGF's repair potential seriously but stresses how much is still unknown about how it works — and warns about people using it in sport before the science is in.

This supports the tesamorelin half of the blend: it reliably cut belly and liver fat in HIV patients. It does not test the combination or apply to general fat loss.

Supports the TB-500 side of the stack via animal repair data. It does not test the combination in people.

Animal repair evidence for the TB-500 component; says nothing about the three-peptide stack.

In rats, BPC-157 sped up healing of gut injuries across many studies. This is a review of animal data, not human evidence.

In a lab dish, the MGF peptide helped human muscle stem cells become more active and better at fusing, especially cells from younger people — a hint of potential, but not evidence that it works or is safe in actual patients.

Supports only the BPC-157 component, and only in animals. It does not test the stack or any human outcome.

Animal-level support for the BPC-157 component only.

Animal-level support for the BPC-157 component only.

Experts reviewing the field argued there isn't solid proof the body actually makes a working MGF peptide, even though synthetic versions sometimes do things in a dish — a sober reminder the basic biology is contested.

KPV gets into gut cells through a known transporter and quiets a key inflammation pathway in a dish.

This is the strong, established side of oxytocin. Pooling 61 trials in nearly 13,000 women, this Cochrane review confirms that intravenous oxytocin reliably helps start and progress labor, which is why it is an FDA-approved obstetric drug. This is a completely different use from the nasal sprays studied for social behavior.

In a dish, Tβ4 made the cells that line blood vessels move around — a behavior linked to growing new vessels during healing.

In Russian stroke trials, Semax was linked to better neurological recovery scores than standard care alone.

The UK's drug regulator publicly told the public not to use Melanotan II.

Pooled across trials, more chronic hepatitis B patients cleared the virus with thymosin alpha-1 than with control treatments.

Lab-dish evidence for the TB-500 component's role in healing; not proof for the blend.

Supports the Semax half of the stack via a stroke trial — Semax by itself, not paired with Selank.

A review of how Semax has been studied for memory and attention in animals and small human groups.

Mice with experimental colitis got better when given KPV by mouth.

Animal anti-inflammatory evidence for the KPV component; not proof for the four-peptide stack.

A review arguing that GHRH peptides like sermorelin are a more natural way to raise GH than injecting GH directly.

One shot of CJC-1295 raised growth hormone and IGF-1 for over a week in healthy adults — but the trial was small and short.

In a small trial in older adults, repeated CJC-1295 doses kept GH and IGF-1 elevated.

In a 12-week trial, AOD-9604 did not help adults with obesity lose meaningfully more weight than placebo did.

Vitamin D made human immune cells produce more LL-37, which helped them kill TB bacteria in a dish.

This trial supports only the CJC-1295 half of the blend: a single injection raised GH and IGF-1 in healthy adults. It says nothing about stacking it with ipamorelin.

In a small Russian study, Selank reduced anxiety as well as a benzodiazepine — but without the same sleepiness.

This is the famous study that started the idea of oxytocin as a 'trust hormone.' In a money game, people who sniffed oxytocin behaved more trustingly than those who got a placebo. It generated huge attention—but later research could not consistently reproduce it, so it should be read as an intriguing early claim rather than settled fact.

Supports the Selank half of the stack for anxiety — a Russian trial of Selank by itself, not the combination.

Rats with cut Achilles tendons healed faster and stronger when given BPC-157 in this lab study.

In rats, muscle damage caused a quick burst of the MGF form of IGF-1 that lined up with muscle stem cells switching on — supporting the idea that natural MGF is an early repair signal, though this says nothing about injecting MGF in people.

Rat-tendon evidence for the BPC-157 half. Encouraging in animals, but not proof for humans or for the combination.

Animal tendon-healing evidence for one of the three components only.

Animal evidence for the MGF component's repair signaling. It does not validate injecting MGF, let alone the full stack.

A review by the lab that developed epitalon, summarizing decades of their own animal and small human work on it.

Pineal peptide preparations seemed to lower oxidative-stress markers in animals and small human groups.

Women who used a GHK-Cu cream for 12 weeks reported firmer, smoother skin compared with placebo.

Real human evidence — but for GHK applied to the skin, not injected, and not in this stack.

Human evidence for GHK on the skin, not injected and not in this stack.

In animals, ipamorelin released growth hormone cleanly, without raising stress hormones the way older drugs did.

This foundational study describes the ipamorelin half of the blend — a clean GH-releaser in animals. It is component evidence, not proof the combination works in people.

Older adults on the sermorelin sequence had higher IGF-1 and small body-composition improvements after months of treatment.

Volunteers using Melanotan II in a small trial reliably became more tan — measured by an instrument, not just by eye.

Animal wounds healed faster with GHK-Cu, and the skin made more collagen.

A historical review that flagged how mixed and confusing the data on DSIP have been since the 1970s.

A small 1980s trial found DSIP modestly improved sleep in people with chronic insomnia.