What the studies show
55 guides. Each one explains what the published research on a compound actually found, in plain words, with a link behind every claim.
Metabolic
- 5-Amino-1MQA small molecule, not a peptide, that blocks the enzyme NNMT. In obese mice it trimmed weight and fat over 11 days; it has never been tested in people.5 min read · Animal and lab studies
- AOD-9604A 16-amino-acid tail of growth hormone that trimmed fat in obese mice, then failed to beat placebo in the human weight-loss trials run by its developer.5 min read · Mixed evidence
- CagrilintideA once-weekly amylin analogue from Novo Nordisk. Alone it produced 10.8% weight loss at 26 weeks; paired with semaglutide as CagriSema, 20.4% at 68 weeks.5 min read · Large human trials
- GLP-R3A triple-hormone agonist in phase 3 trials. In a 48-week phase 2 study, the highest dose produced the largest weight loss ever reported for a drug.5 min read · Large human trials
- GLP-SMThe GLP-1 agonist approved as Ozempic, Wegovy and Rybelsus: 14.9% average weight loss at 68 weeks in STEP 1, and 20% fewer major heart events in SELECT.5 min read · Large human trials
- GLP-TRZA dual GIP/GLP-1 agonist, approved as Mounjaro and Zepbound. In the 72-week SURMOUNT-1 trial, the 15 mg group lost an average of 20.9% of body weight.5 min read · Large human trials
Repair & recovery
- ARA-290An 11-amino-acid piece of erythropoietin, built to protect tissue without making red blood cells, tested in small trials for small-fiber nerve damage.5 min read · Small human studies
- BPC-157A 15-amino-acid piece of a stomach protein, studied for tendon, muscle and gut repair — almost entirely in rats.5 min read · Animal and lab studies
- TB-500A seven-amino-acid piece of thymosin beta-4, the protein that lets cells move — studied for wounds, hearts and eyes, almost always as the full protein.5 min read · Mixed evidence
- Wolverine BlendTwo peptides with separate animal records for tendon, wound and vessel repair, paired by reputation rather than by any study of the two together.5 min read · Animal and lab studies
Growth hormone axis
- CJC-1295 (no DAC)Sermorelin with four amino acids swapped to survive the blood longer, and without the albumin-binding tail that gave the DAC version its week-long half-life.5 min read · Animal and lab studies
- CJC-1295 + IpamorelinTwo peptides for two receptors on the same pituitary cell. The idea comes from a 1990 study in men; the pair itself has never been tested together.5 min read · Mixed evidence
- CJC-1295 with DACA GHRH analogue that bonds to albumin in the blood: one injection raised growth hormone for about a week in healthy adults, with the normal pulses intact.5 min read · Small human studies
- GHRP-2The potent GHRP approved in Japan as a one-dose test for growth hormone deficiency, and shown to make healthy men eat about a third more at a single meal.5 min read · Small human studies
- GHRP-6The 1984 hexapeptide that came before its own receptor and before ghrelin — and the reason the hunger it causes is the receptor doing its job.5 min read · Small human studies
- HexarelinGHRP-6 with one methyl group added, active by mouth and nose as well as by injection, and the GHRP whose growth hormone response was shown to fade by 16 weeks.5 min read · Small human studies
- IGF-1 LR3An engineered IGF-1 that dodges the body's binding proteins. Built in Adelaide in 1992 as a cell-culture reagent, and that is still where its evidence lives.5 min read · Animal and lab studies
- IpamorelinA five-amino-acid ghrelin mimetic built at Novo Nordisk to release growth hormone without the cortisol rise of the older GHRPs.5 min read · Small human studies
- SermorelinThe first 29 amino acids of GHRH, once an FDA-approved drug for children who do not make enough growth hormone, and withdrawn from the market in 2008.5 min read · Large human trials
- TESAThe one GHRH analogue that became an approved drug: Egrifta, for abdominal fat in HIV lipodystrophy, on the strength of two 26-week phase 3 trials.6 min read · Large human trials
Skin & hair
- AHK-CuOne amino acid away from GHK-Cu, with one published study behind it: human hair follicles in a dish, in Seoul, in 2007.4 min read · Lab studies only
- Collagen PeptidesNot one molecule but a mixture of fragments of a structural protein, swallowed in grams, with small manufacturer-funded trials on skin behind it.5 min read · Small human studies
- GHK-CuThree amino acids holding one copper atom, found in human blood in 1973 and studied for skin, wounds and hair — mostly in cells and animals.5 min read · Animal and lab studies
- GLOW BlendThree peptides with three separate research records — skin cells, rat tendons and animal wounds — and no study of the three together.5 min read · Animal and lab studies
- KLOW BlendGLOW plus KPV, a three-amino-acid piece of a hormone studied for gut inflammation in mice — and, as with GLOW, no study of the combination.5 min read · Animal and lab studies
- MT-1A tanning peptide from 1980s Arizona that became Scenesse, an approved implant for a rare disease in which sunlight causes burning pain.5 min read · Large human trials
- MT-2A seven-amino-acid ring that tanned a handful of men in the 1990s, gave them unplanned erections, and was never approved anywhere.5 min read · Small human studies
Mood & cognition
- CerebrolysinA peptide mixture extracted from pig brains, approved in Austria and Russia, that missed its primary endpoint in a 1,070-patient stroke trial.5 min read · Large human trials
- DihexaAn angiotensin IV analogue that grew new synapses on rat neurons and reversed drug-induced memory loss in rats, and has never been given to a human.5 min read · Animal and lab studies
- DSIPA nine-amino-acid peptide pulled from sleeping rabbits in 1977 that, almost fifty years on, still has no known gene, receptor or mechanism.5 min read · Small human studies
- OxytocinThe hormone of labour wards and the "trust molecule" headlines — and the registered replication that found no effect on trust at all.5 min read · Mixed evidence
- PinealonA three-amino-acid peptide from a St Petersburg laboratory, studied almost entirely in cell dishes and rats by the group that designed it.4 min read · Animal and lab studies
- SelankA seven-amino-acid peptide built on the immune fragment tuftsin, registered in Russia as a nasal anxiety medicine on the strength of small open-label trials.5 min read · Small human studies
- SemaxA seven-amino-acid fragment of the stress hormone ACTH, given as nasal drops in Russian stroke wards since the 1990s and never tested in a blinded trial.5 min read · Mixed evidence
Longevity & mitochondria
- CarnosineA two-amino-acid peptide found in meat extract in 1900, stored in muscle and brain, and raised in trials by feeding one of its two halves.5 min read · Small human studies
- EpithalonA four-amino-acid copy of a pineal gland extract, from a St Petersburg laboratory that reported telomerase activation in human cells in 2003.5 min read · Animal and lab studies
- GlutathioneThe most abundant small antioxidant in human cells: three amino acids joined by a bond that ordinary peptidases cannot cut.5 min read · Small human studies
- HumaninA 24-amino-acid peptide encoded inside mitochondrial DNA, found in 2001 in the brain of an Alzheimer's patient and since tied to how long animals live.5 min read · Animal and lab studies
- MOTS-CA 16-amino-acid peptide encoded by mitochondrial DNA, not the nucleus, that rises with exercise and kept mice on a high-fat diet from becoming obese.5 min read · Animal and lab studies
- NAD+The coenzyme every cell uses to move electrons, which falls with age in human skin and brain. Most of the human trials gave a precursor, not NAD+ itself.6 min read · Small human studies
- NMNThe direct precursor to NAD+, which raised muscle insulin sensitivity by about 25% in prediabetic women over ten weeks and changed little else.5 min read · Small human studies
- SS-31A four-amino-acid peptide that binds the inner membrane of mitochondria. In 2025 it became the first approved drug for Barth syndrome.5 min read · Large human trials
Sexual health & hormones
- HCGThe pregnancy hormone that acts like a long-lasting pulse of LH, an approved fertility drug for decades — and the subject of a diet claim the evidence rejects.5 min read · Large human trials
- Kisspeptin-10The signal at the top of the reproductive axis, found because children without its receptor never reach puberty, and studied only in small infusion trials.5 min read · Small human studies
- PT-141A metabolite of a tanning peptide that became Vyleesi, the first as-needed drug approved for low sexual desire in premenopausal women.5 min read · Large human trials
Immune & gut
- KPVThe last three amino acids of a tanning hormone, which keep its anti-inflammatory signal but not its pigment — studied in mouse colitis.5 min read · Animal and lab studies
- LL-37The body's own antibiotic peptide, made in skin and white blood cells, which kills microbes in a dish and also drives rosacea and psoriasis.5 min read · Mixed evidence
- Thymosin Alpha-1A 28-amino-acid thymus peptide that is an approved hepatitis B drug in China and Italy, tested in sepsis and cancer trials with unsettled results.6 min read · Large human trials
- ThymulinA nine-amino-acid thymus hormone that only works with a zinc atom attached, found in 1977 and studied for pain and inflammation in rodents.5 min read · Animal and lab studies
- VIPA 28-amino-acid gut hormone that widens blood vessels, sets the brain's clock and calms immune cells — an approved drug in a few countries, in a tiny niche.5 min read · Mixed evidence
How peptides work
- How peptide purity is measuredAn HPLC purity figure is a ratio of peak areas on one chromatogram. It says how clean a sample is, not what it is or how much is in the vial.5 min read · Mixed evidence
- How peptides degrade, and what slows itFour reactions wear peptides down — deamidation, oxidation, hydrolysis and aggregation — and every one of them needs water, heat, light or the wrong pH.5 min read · Mixed evidence
- How to read a certificate of analysisA certificate of analysis is a lab's record of what it measured in one sample on one day. Every line answers a specific question, and a few are often missing.5 min read · Mixed evidence
- Progression H2OWater for injection with 0.9% benzyl alcohol added so a multiple-dose vial can be entered more than once. The alcohol has a history of its own.5 min read · Mixed evidence
- Why a freeze-dried cake looks the way it doesThe white solid in a vial is the skeleton left behind when ice was removed by sublimation. How it looks was decided by how the water froze.5 min read · Mixed evidence