Every peptide, explained simply

What each one is actually used for, in normal words. Every guide says up front whether it is a real medicine you can be prescribed, or something sold online that has never been tested in people.

What the labels mean

Approved medicine: Licensed by medicines regulators for at least one condition, and prescribed for it.
Prescribed off-label: A real prescription medicine, but commonly prescribed for something it was not licensed for.
Used in skincare: Sold in creams and serums rather than as a medicine. Regulated as a cosmetic, not a drug.
Research only: Not approved for human use anywhere. Sold labelled 'for research use only', which is a legal position, not a safety one.

Weight and appetite

The ones people take to eat less and lose weight.

Approved medicineStrong human evidence

Liraglutide

Also called Saxenda, Victoza

The daily injection that came before Ozempic. Less weight loss than the weekly options, but well studied and often easier to get.

Weight and appetite

Approved medicineStrong human evidence

Semaglutide

Also called Ozempic, Wegovy, Rybelsus

The weekly injection behind Ozempic and Wegovy. It reduces appetite, and in trials people lost around 15% of their body weight.

Weight and appetite

Approved medicineStrong human evidence

Tirzepatide

Also called Mounjaro, Zepbound

The strongest weight loss medicine currently approved. It works on two gut hormones instead of one, and trial results reached about 20%.

Weight and appetite

Research onlyEarly human evidence

AOD-9604

Also called Anti-Obesity Drug 9604, HGH fragment 176-191

A growth hormone fragment sold as a fat burner. It was tested properly in humans, and in the trial that mattered it did not beat placebo.

Weight and appetite

Recovery and injury

Used for healing, joints, tendons and training recovery.

Research onlyNo human trials

BPC-157

Also called Body Protection Compound 157, Pentadecapeptide BPC 157

The most talked-about healing peptide online. Thirty years of promising rat studies, and not one completed human trial to show for it.

Recovery and injury

Research onlyNo human trials

TB-500

Also called Thymosin Beta-4, TB4

Usually sold alongside BPC-157 as a healing stack. Interesting biology, animal data, and no completed human trial for injury recovery.

Recovery and injury

Skin and hair

Anti-ageing creams, hair growth, and what actually absorbs.

Used in skincareMixed human evidence

Argireline

Also called Acetyl hexapeptide-8, Acetyl hexapeptide-3

Marketed as topical Botox for expression lines. It does relax muscle signalling, but a cream reaches nowhere near as deep as an injection.

Skin and hair

Used in skincareMixed human evidence

GHK-Cu

Also called Copper peptide, Copper tripeptide-1

The blue copper peptide in serums. One of the few skincare peptides with real human studies behind the firmness and fine-line claims.

Skin and hair

Used in skincareMixed human evidence

Matrixyl

Also called Palmitoyl pentapeptide-4, Matrixyl 3000

A collagen-signalling peptide found in a huge number of anti-ageing serums. Gentler than retinol, with smaller and slower results.

Skin and hair

Hormones and growth

Growth hormone boosters and the hormone-adjacent ones.

Approved medicineStrong human evidence

Tesamorelin

Also called Egrifta

An approved medicine that reduces deep belly fat by prompting the body to release its own growth hormone. Licensed for a specific condition.

Hormones and growth

Prescribed off-labelMixed human evidence

Sermorelin

Also called Geref, GHRH 1-29

A prescription growth hormone booster from compounding pharmacies. Widely used in anti-ageing clinics, with modest evidence for those claims.

Hormones and growth

Research onlyNo human trials

CJC-1295

Also called Modified GRF 1-29, CJC-1295 DAC

The long-acting growth hormone releaser usually stacked with Ipamorelin. Raises growth hormone reliably; the benefits remain untested.

Hormones and growth

Research onlyNo human trials

Ipamorelin

Also called NNC 26-0161

A growth hormone releasing peptide popular in anti-ageing circles. Selective and well tolerated in studies, but never approved for anyone.

Hormones and growth

Sex and libido

Desire and erectile function, including one approved for women.

Approved medicineMixed human evidence

Bremelanotide

Also called Vyleesi, PT-141

An approved medicine for low sexual desire in premenopausal women. It works on the brain rather than blood flow, and effects are modest.

Sex and libido

Research onlyNo human trials

Melanotan II

Also called MT-2, The tanning injection, Barbie drug

The tanning injection sold online. It works, which is the problem: it also drives moles to darken and has no approved use anywhere.

Sex and libido

Sleep, mood and focus

Marketed for calm, memory and mental sharpness.

Research onlyNo human trials

Selank

Also called TP-7

A Russian anti-anxiety peptide sold as a nasal spray. Approved in Russia, unapproved elsewhere, and barely studied outside it.

Sleep, mood and focus

Research onlyNo human trials

Semax

Also called N-acetyl semax, ACTH 4-10 analogue

A nootropic nasal spray from the same Russian programme as Selank. Used there after stroke; sold everywhere else for focus and memory.

Sleep, mood and focus

Longevity

Sold for ageing and energy. The thinnest evidence on the site.

Research onlyNo human trials

Epitalon

Also called Epithalon, AEDG peptide

Sold as the telomere peptide and marketed for lifespan. The claims trace back to a small body of work from one Russian institute.

Longevity

Research onlyMixed human evidence

Thymosin alpha-1

Also called Zadaxin, Ta1

An immune-modulating peptide approved in dozens of countries but not the US or UK. Real hospital use, oversold as a wellness product.

Longevity

Missing one you were looking for? The list grows over time. How this site works.

What the labels mean

Weight and appetite

Recovery and injury

Skin and hair

Hormones and growth

Sex and libido

Sleep, mood and focus

Longevity

All 19 peptides, A to Z