Compare Peptides

Select any two compounds for a side-by-side comparison of mechanism, uses, risks, and FDA regulatory status.

Popular comparisons

AHK-Cu

Copper Tripeptide AHK, Ala-His-Lys:Copper

Unregulated
Anti-Aging & Skin

GHK-Cu

Copper Peptide, Glycyl-L-histidyl-L-lysine:copper(II)

Pending PCAC
Anti-Aging & Skin
Overview

A newer copper-binding tripeptide related to GHK-Cu but with a different amino acid sequence (Ala-His-Lys vs Gly-His-Lys). Emerging research suggests it may have distinct and potentially complementary effects on hair growth and skin rejuvenation.

A naturally occurring copper-binding tripeptide found in human plasma, saliva, and urine. Levels decline significantly with age. Widely used in both injectable and topical forms for anti-aging.

Mechanism of Action

Binds copper ions similarly to GHK-Cu but activates different signaling pathways. Appears to stimulate Wnt/β-catenin signaling in hair follicle dermal papilla cells, promoting hair growth through a mechanism distinct from GHK-Cu's wound healing pathway.

Activates wound healing genes, promotes collagen and elastin synthesis, stimulates blood vessel growth, and has anti-inflammatory and antioxidant properties. The copper ion is essential for many enzymatic processes in tissue remodeling.

Common Uses
  • Hair growth stimulation
  • Skin rejuvenation
  • Anti-aging
  • Wound healing support
  • Skin rejuvenation and anti-aging
  • Wound healing
  • Hair growth stimulation
  • Collagen production
  • Reducing inflammation
Known Risks
  • Very limited research compared to GHK-Cu
  • Most studies are in vitro
  • Potential copper toxicity at high doses
  • Not well-characterized safety profile
  • Generally well-tolerated topically
  • Injectable form has less safety data
  • Potential copper toxicity at high doses
  • Skin irritation possible with topical use
Regulatory Status
Unregulated

No FDA regulatory category. Available as a research chemical and in some cosmetic formulations. Not subject to the same regulatory scrutiny as GHK-Cu injectable.

Pending PCAC

GHK-Cu has a notably complex status after the April 15, 2026 FDA announcement. Injectable GHK-Cu is being removed from Category 2 (significant safety risks), while non-injectable GHK-Cu is simultaneously being removed from Category 1 (active evaluation). Both forms are scheduled for a unified PCAC review before February 2027. Topical cosmetic use is unaffected. Injectable use is now in regulatory gray zone — compounding pharmacies should not assume authorization until PCAC acts.

PCAC: By February 2027

This comparison is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy.