Every peptide, graded

A natural building-block your own cells use to make haem and fuel your mitochondria. It's a licensed medicine — but as a glow-in-the-dark dye for brain-tumour surgery, not as the energy-and-metabolism supplement it's sold as.

A lab-made small molecule that blocks an enzyme (NNMT) to nudge fat tissue toward burning rather than storing energy — convincing in obese mice, completely untested in people.

A synthetic copper-carrying peptide used in hair and skin cosmetics, with promising lab data but no human trials proving it works.

A synthetic fragment of growth hormone designed to burn fat without the hormone's side effects, but human trials showed it failed to produce meaningful weight loss and development was abandoned.

A lab-made 11-amino-acid offcut of the hormone EPO, engineered to keep its tissue-repair and anti-inflammatory effects while losing the red-blood-cell boost — with promising but unfinished human trials in nerve damage.

An experimental peptide that kills the blood vessels feeding fat tissue, with striking results in mice and a few monkeys.

A lab-made six-amino-acid peptide sold in anti-ageing creams as a topical Botox alternative, with a plausible mechanism but thin, mostly cosmetic-grade human evidence and a serious question over whether it can penetrate skin at all.

A lab-made peptide based on a fragment of a protein found in stomach fluid, widely studied in animals for tissue repair but essentially untested in humans.

A synthetic long-acting trigger for growth hormone release, tested in humans briefly in the early 2000s and then abandoned. Sold now only as an unlicensed research chemical.

An investigational once-weekly injection combining semaglutide with cagrilintide (a synthetic amylin analogue) to achieve greater weight loss than either component alone.

Cagrilintide is an experimental once-weekly injection mimicking the body's fullness hormone amylin to reduce appetite and body weight. The trial results are impressive, but it is not yet an approved medicine.

An injectable mix of small protein fragments from pig brain, used in some countries for stroke and dementia, but independent reviewers say the evidence of benefit is weak.

A lab-made four-amino-acid peptide, derived from a cow-brain extract, that Russian researchers claim repairs nerves and protects the brain, but the real evidence is almost all from rats and cell dishes produced by one group, with no proper human trials.

A brain peptide discovered in sleeping rabbits in the 1970s and tested as a sleep aid in humans, but development stalled and it never became a licensed medicine.

An experimental memory-drug candidate derived from a blood-pressure hormone fragment that showed dramatic effects in rats but has never been tested in humans, and whose foundational study was retracted for falsified data.

Epitalon is a lab-made four-amino-acid peptide promoted as an anti-ageing telomere treatment, but the human evidence behind those claims is thin and largely from one research group.

A natural protein that jams the muscle-growth brake by binding myostatin, but the only real human evidence comes from gene therapy in muscular dystrophy patients, not from the injectable peptide sold online.

A tiny copper-carrying skin peptide with modest and mixed human evidence as a topical anti-ageing cosmetic, and almost none for the injectable 'whole-body regeneration' claims sold online.

A lab-made peptide that prompts the pituitary to release a burst of growth hormone. It is a licensed single-dose diagnostic test in Japan but is sold elsewhere as an unlicensed research chemical for bodybuilding and anti-ageing, where long-term evidence barely exists.

An old experimental peptide that genuinely makes your body release a burst of its own growth hormone, but which was never turned into an approved medicine and is sold today only as an unlicensed research chemical.

Glutathione is the body's main built-in antioxidant. The biology is real, but swallowing or injecting it as an anti-ageing or skin-lightening treatment rests on thin human evidence and, for IV use, real safety warnings.

Gonadorelin is a lab-made copy of the brain's own fertility hormone (GnRH) that tells the pituitary gland to release the hormones driving the testes and ovaries. It only works properly when delivered in tiny, regular pulses, the way the body does it naturally.

The tail-end snippet of growth hormone that's marketed as a "fat-burning" peptide, based mostly on mouse studies - the human version of this idea (AOD-9604) was tested properly and didn't work.

An old experimental peptide that triggers a growth hormone burst, but the body quickly adapts and it was never approved as a medicine.

A tiny protective peptide your own mitochondria make, which looks fascinating in lab animals and correlates with healthy ageing in people, but has never been properly tested as a drug in humans.

A lab-engineered, longer-lasting version of the body's growth factor IGF-1, sold as a "research chemical" for muscle building, though it has never been tested in humans for that purpose.

A lab-made peptide that nudges your own pituitary gland to release a pulse of growth hormone. Proven to do that in humans, but never proven to actually make anyone healthier, stronger or leaner.

A three-amino-acid fragment of alpha-MSH that suppresses inflammation in cell and animal studies but has never been tested in humans.

A short lab-made copy of a brain hormone that controls reproduction. Small human studies hint at effects on sexual arousal, but the data is early and the evidence grade reflects that.

A natural germ-killing peptide your own body makes to fight infection and help heal skin, tested in real wound-healing trials that have so far been promising but inconclusive.

An experimental gut-barrier peptide that aimed to be the first drug for coeliac disease, but failed its large Phase 3 trial and is approved nowhere.

A clinic-mixed injection of everyday nutrients (methionine, inositol, choline, often with carnitine and B-vitamins) marketed as a fat-burner, with no controlled human evidence that the shot itself burns fat.

A daily injectable prescription medicine that mimics a natural gut hormone to reduce appetite and aid weight loss, sold as Saxenda for weight management and Victoza for type 2 diabetes.

A growth-hormone-boosting pill that genuinely raises IGF-1 and adds a little lean mass, but in every completed trial it failed to make people stronger, healthier or better-functioning. Its maker abandoned it.

A tiny peptide your own mitochondria produce during exercise, promising for metabolism in mice, but in humans only measured as a biomarker rather than proven to work as an injected drug.

A lab-made fragment of collagen, attached to a fatty acid so it can sink into skin, used in face creams to nudge skin cells into making a bit more collagen.

An injectable obesity drug, approved in China but not the UK, that mimics two gut hormones to suppress appetite and increase energy expenditure.

A synthetic copy of a natural hormone that activates skin pigmentation. The same molecule is an approved medicine for a rare phototoxic disease and, separately, an unlicensed grey-market tanning product.

An unlicensed injectable peptide that darkens skin without sun exposure, sold illegally in the UK and linked to nausea, prolonged erections and worrying changes in moles.

A chemically tweaked, longer-lasting version of the Russian nootropic peptide Semax, sold online for focus and brain health but never tested in a human trial in its own right.

A coenzyme your cells already make and use for energy and DNA repair; levels fall with age, so people take it (or its precursors) hoping to turn back the clock, but the human anti-ageing evidence is thin.

A NAD+ building-block sold as an anti-ageing supplement; it genuinely raises NAD+ levels in human blood, but whether that does anything meaningful for ageing or healthspan is still unproven.

A form of vitamin B3 that genuinely raises the cellular fuel-handling molecule NAD+ in people, sold as an anti-ageing supplement, but human trials have mostly failed to show it makes you meaningfully healthier.

Oxytocin is a natural hormone and a genuine, decades-old hospital medicine for childbirth that has been heavily marketed as a "love and bonding" nasal spray, but that bonding use mostly fails to hold up in good trials.

An experimental brain peptide designed from a natural nerve-growth factor that improves memory and reduces Alzheimer's-like pathology in mice, but has never been tested in humans.

An experimental brain peptide that blocks the TREK-1 potassium channel to act like a fast antidepressant in mice, with zero human testing to date.

A brain-acting peptide that affects sexual desire through melanocortin receptors. It is the only such drug actually approved (in the US, as Vyleesi) for low sexual desire in premenopausal women.

A lab-made three-amino-acid peptide claimed to protect brain cells. The evidence is almost entirely from cell dishes and rodents, produced by one research group, with no proper human trials.

A Russian "bioregulator" sold for prostate health that is really two different products under one banner — a lab-made four-amino-acid peptide with only cell and animal data, and a cow-prostate extract backed by weak Russian studies.

An experimental once-weekly injectable that hits three metabolic hormone receptors at once and has produced the largest trial weight-loss results seen so far. It is not yet an approved medicine.

A face-cream peptide marketed as a needle-free, milder cousin of Botox. The mechanism is plausible, but the evidence is thin and mostly from the manufacturer.

A peptide that homes in on the power plants of your cells to help them work better. It is now a genuine, if narrowly approved, medicine for one rare disease, but unproven for the anti-ageing uses it is hyped for.

A nasal-spray anxiety peptide developed and prescribed in Russia, with promising but mostly Russian small-scale human evidence and no licence in the UK.

A licensed prescription medicine that mimics a gut hormone to suppress appetite, improve blood sugar, and reliably produce weight loss.

A Russian brain peptide, prescribed there for strokes and concentration problems, that raises brain growth factors in animals but has almost no independent Western trial evidence.

A synthetic fragment of the body's own growth-hormone-releasing hormone that nudges the pituitary to make its own growth hormone. Once an approved medicine, now sold grey-market for largely unproven anti-ageing claims.

An experimental once-weekly weight-loss and liver-disease injection that works on two metabolic hormone targets at once. Strong trial results so far, but not yet approved anywhere.

A lab-made fragment of a natural repair protein, sold as a research chemical for healing and recovery on the strength of animal studies, with no proven human benefit.

A lab-made copy of the body's own growth-hormone trigger that is an approved prescription medicine in the US for shrinking deep belly fat in people with HIV, but is not licensed in the UK.

A failed Parkinson's/Alzheimer's brain drug, repurposed as a potent appetite suppressant — it produced striking weight loss in a Phase II trial but has never made it through to a licensed obesity medicine.

A Soviet-era extract of calf thymus glands, claimed to "reset" an ageing immune system — backed by decades of striking-looking Russian longevity data that almost nobody outside Russia has been able to check or repeat.

A lab-made copy of a natural thymus-gland peptide that fine-tunes the immune system. It is a licensed prescription medicine in many countries (as Zadaxin) but not in the UK, where it is sold only as an unlicensed research chemical.

A natural zinc-dependent thymus hormone that helps immune cells mature, sold as a research peptide despite almost no convincing human trial evidence as a treatment.

A prescription injection that mimics two gut hormones at once to reduce appetite, lower blood sugar and drive substantial weight loss.

A natural body hormone that relaxes blood vessels and airways and dampens inflammation. Its lab-made version was tested in serious lung disease but failed to prove it works.

Vilon is a lab-made two-amino-acid peptide (Lys-Glu) from the Russian 'bioregulator' family, promoted for immune ageing and longevity, but the human evidence is essentially limited to cells in a dish.