Skin & cosmetic peptides

The peptides used in skincare and aesthetics — the “Botox-like” line relaxers, the collagen-boosting matrikines, the under-eye, hair and pigment peptides — grouped by what they are meant to do, with the copper peptide GHK-Cu as the most famous of the class.

Topical is a different world from injected. Most compounds here are established cosmetic ingredients used in creams and serums, where the main question is whether they do much; a few (GHK-Cu, PDRN, melanotan II) are also injected on the grey market, which is a different and higher risk. Nothing here is medical advice.

Do cosmetic peptides work?

Two things decide it. A topical peptide has to actually penetrate the skin to do anything — many barely do — and even when it does, the measured effects are usually modest. The better-studied ones (the Matrixyl matrikines, argireline) have real if small data; much of the rest is marketing. The grouping below is by intended effect, with the evidence stage marked.

Two classes of cosmetic peptide, side by side

A copper “signal” peptide against a “wrinkle-relaxing” one — the two do quite different things. The full page compares them in detail.

	GHK-Cu	SNAP-8
Type	Copper signal / repair peptide	Wrinkle-relaxing (neuromodulating) peptide
Aims to	Skin renewal, collagen, tone	Softens expression lines
Route	topical (cream, serum) and, outside any approval framework, subcutaneous	topical, in a cream, serum or emulsion
Evidence	Topical data; injected use unstudied	Preclinical; modest

Full comparison: GHK-Cu vs SNAP-8.

The full skin & cosmetic family

Every skincare- and aesthetics-marketed peptide in the reference, grouped by purpose.

Wrinkle-relaxing (“Botox-like”) peptides

Peptides that aim to soften expression lines by interfering with nerve-to-muscle signalling.

Argireline In trials Topical hexapeptide that inhibits SNARE complex formation and is said to soften expression lines.
SNAP-8 Experimental Topical octapeptide, an extended argireline variant aimed at inhibiting SNARE complex formation.
Leuphasyl Experimental Topical enkephalin-analogue pentapeptide marketed for expression lines; almost no independent research exists.
SYN-AKE Experimental Topical synthetic mimic of a snake venom peptide, intended to block muscle nicotinic acetylcholine receptors.
Pentapeptide-3 (Vialox) Experimental Topical peptide modelled on temple viper venom, claimed to block the muscle acetylcholine receptor.

Collagen-boosting matrikines

Fatty-acid-tailed peptides that signal the skin to make more collagen — the Matrixyl family and its relatives.

Matrixyl In trials Topical matrikine peptide with a fatty acid tail said to stimulate collagen and extracellular matrix.
Matrixyl 3000 Experimental Trade-name blend of two palmitoylated matrikine peptides used topically for wrinkles and skin firmness.
Palmitoyl tripeptide-1 Experimental Topical fatty-acid-tailed version of the matrikine GHK, used to signal collagen synthesis in the dermis.
Palmitoyl tripeptide-5 Experimental Cosmetic peptide claimed to activate TGF-beta and build collagen; no published clinical trial exists.
Palmitoyl tetrapeptide-7 (Rigin) Experimental Anti-inflammatory cosmetic peptide; the second half of Matrixyl 3000, with no evidence of its own.

Under-eye & antioxidant

Peptides aimed at eye bags, dark circles and glycation.

Acetyl tetrapeptide-5 (Eyeseryl) Experimental The dominant 'eye bag' cosmetic peptide; its evidence is one manufacturer trial of about twenty people.
Carnosine (Ignotine) In trials Endogenous dipeptide used topically against glycation and taken orally, where serum carnosinase destroys most of it.

Growth factors & regeneration

Recombinant growth factors and DNA fragments used in skincare and injectable aesthetics.

sh-Oligopeptide-1 In trials Recombinant human EGF sold in topical skincare; the evidence and the criticism of it are both substantial.
PDRN (Polydeoxyribonucleotide, Polynucleotides) In trials Fish-derived DNA fragment mixture injected into skin for rejuvenation — a nucleotide product, not a peptide.

Hair & scalp

Peptides marketed for hair growth and scalp health.

Acetyl tetrapeptide-3 Experimental Topical tetrapeptide used mainly in hair and scalp products, marketed for follicle anchoring and matrix support.
PTD-DBM Experimental Cell-penetrating peptide for hair regrowth via CXXC5-Dishevelled disruption; one mouse study, no human data.
Zinc-thymulin (ZT) In trials Zinc-complexed thymic nonapeptide sprayed on the scalp for hair loss; one small open-label pilot.

Pigment & tanning

The melanocortin agonists that affect skin colour.

Afamelanotide (Scenesse) Approved Approved alpha-MSH analogue implant for light-induced pain in erythropoietic protoporphyria.
Melanotan II (MTII) In trials Unapproved melanocortin agonist that tans the skin; reports of melanoma and systemic toxicity.

Skin & cosmetic peptides: common questions

Do topical peptides in skincare actually work?

Some have modest evidence, but two catches apply to all of them. First, a peptide has to survive the formula and actually penetrate the skin to do anything — many do not, or barely. Second, the effects that are shown are usually small. Peptides can be a reasonable ingredient, but the marketing tends to run well ahead of the data.

What is the difference between argireline and SNAP-8?

They are close relatives. Argireline (acetyl hexapeptide-8) is the original “Botox in a jar” peptide; SNAP-8 (acetyl octapeptide-3) is a longer, extended version marketed as more effective. Both aim at the same nerve-signalling step, and both are topical — nothing like the injected effect of actual botulinum toxin.

What is Matrixyl?

Matrixyl is a trade name for palmitoyl pentapeptide-4, a collagen-signalling “matrikine” peptide with a fatty-acid tail to help it penetrate. Matrixyl 3000 is a branded blend of two such peptides. They are among the better-studied cosmetic peptides, though the effects are modest.

Is a peptide serum as good as Botox or retinol?

No. Topical “Botox-like” peptides do not reproduce an injection of botulinum toxin, and for anti-ageing the evidence for retinoids is stronger than for most peptides. Peptides can be a gentle complement, not a replacement. Nothing here is medical or cosmetic-medical advice.

Are cosmetic peptides safe?

Topically, the established cosmetic peptides are generally well tolerated. The risk rises with the grey-market injectables — GHK-Cu, PDRN or melanotan used under the skin rather than in a cream — which are a different proposition; see injection safety.

Browse all skin & cosmetic entries · GHK-Cu · How to read the research · Injection safety