Skin and cosmetic
Compounds sold as cosmetics or supplements for skin, including copper peptides and SNAP-8, plus glutathione.
Which of these has the most human evidence? See Best Peptides for Skin, Ranked by Human Evidence.
aka Copper Tripeptide-1 · Copper peptide · Cu-GHK
Topical cosmetic anti-aging - fine lines, skin density and firmness, elasticity, photodamage, hyperpigmentation - and wound healing. Also marketed in hair-loss cosmetics.
Limited human dataCosmetic
aka Acetyl Octapeptide-3 · Acetyl Octapeptide-1 · SNAP-8™
Topical cosmetic anti-wrinkle ingredient in serums, gels and emulsions, marketed as a longer version of the neurotransmitter-release-inhibiting peptide family that includes Argireline (acetyl hexapeptide-8).
Animal / lab onlyCosmetic
aka GSH · L-Glutathione · Reduced Glutathione
Naturally synthesized in nearly all human cells as the body's principal intracellular antioxidant. Sold as an oral dietary supplement, and marketed by IV/wellness clinics and online sellers as an injectable "glutathione push" or "skin whitening" infusion - a use with no FDA-approved product behind it.
Limited human dataDietary supplement
Side by side
Doses for unapproved compounds are common practice, not trial-established.
| Compound | Main use | Evidence | Usual dose | US status |
|---|---|---|---|---|
| GHK-Cu | Topical cosmetic anti-aging - fine lines, skin density and firmness, elasticity, photodamage, hyperpigmentation - and wound healing. Also marketed in hair-loss cosmetics. | Limited human data | 1-2 mg, once daily, before bed | Cosmetic |
| SNAP-8 | Topical cosmetic anti-wrinkle ingredient in serums, gels and emulsions, marketed as a longer version of the neurotransmitter-release-inhibiting peptide family that includes Argireline (acetyl hexapeptide-8). | Animal / lab only | No consistent protocol | Cosmetic |
| Glutathione | Naturally synthesized in nearly all human cells as the body's principal intracellular antioxidant. Sold as an oral dietary supplement, and marketed by IV/wellness clinics and online sellers as an injectable "glutathione push" or "skin whitening" infusion - a use with no FDA-approved product behind it. | Limited human data | 200-1200 mg, 1-3 times weekly, intramuscular (glute or deltoid) | Dietary supplement |