GHK-Cu and AHK-Cu—copper-binding tripeptides with distinct mechanisms. GHK-Cu has topical human data from wound healing and skin contexts; hair-specific clinical evidence is limited to cosmetic-use observations.

📖 Read the full Copper Peptides (Hair) research overview →

Evidence Tier: Tier 3 — Pilot / Limited Human Data · Peptidings Verdict: Reasonable Bet