Skin, hair and pigmentation

Topical cosmetic peptides like GHK-Cu and acetyl octapeptide-3 have a long history in skincare formulation, with modest supporting studies. Melanocortin agonists act on pigment cells. Afamelanotide is approved for a rare light-sensitivity disorder, while melanotan II has never been approved and is associated with case reports of serious adverse effects.

8 compounds, strongest evidence first

MC1R agonist (α-MSH analog) Melanotan I Melanotan I is afamelanotide, a stabilized analog of alpha-MSH. Approved medicine
Antioxidant tripeptide Glutathione Glutathione is the main intracellular antioxidant, a tripeptide made by nearly every cell. Human RCTs
Copper-binding tripeptide GHK-Cu GHK-Cu is a naturally occurring copper-binding tripeptide found in human plasma, saliva and urine. Early human data
Non-selective melanocortin agonist Melanotan II Melanotan II is a synthetic cyclic peptide developed at the University of Arizona in the 1990s as a sunless tanning agent. Early human data
Cosmetic neurotransmitter-modulating peptide SNAP-8 SNAP-8 is a cosmetic peptide marketed to reduce expression lines by mimicking part of the SNAP-25 protein. Early human data
Multi-peptide blend GLOW blend GLOW is a supplier name for a three-part vial of GHK-Cu, BPC-157 and TB-500, marketed for skin and tissue repair. Animal studies
Multi-peptide blend KLOW blend KLOW adds the anti-inflammatory tripeptide KPV to the three components of GLOW. Animal studies
Tripeptide GHK (copper-free) GHK without copper is the free tripeptide. Cell studies