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Cosmetic OTCCopper Tripeptide+2 more

AHK-Cu

A copper-binding tripeptide marketed primarily for hair regrowth. We read all 2 studies. The protocol is below.

Updated 03 May 2026Read 9 minEvidence ●●○○○Citations 2

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The AHK-Cu Report · $19

Everything you need to start: dose, sourcing, safety, our verdict.

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Built from 2 cited studies.

Status
OTC
Class
Copper Tripeptide
Evidence
2/ 5●●○○○
Regulatory status
Randomized human trials
Read this if
  • you're trying to figure out whether "AHK-Cu" and "GHK-Cu" are the same thing (they're not — different tripeptide, mostly the same copper-delivery game)
  • you're already on finasteride plus minoxidil and looking for a third lever
  • you live in the Tressless subreddit and want to know if copper peptides are real
  • you're a postpartum-shedding reader who shops The Ordinary and wants the honest read
Skip this if
  • you haven't tried minoxidil or finasteride yet — start there
  • you want a head-to-head trial against a drug that actually works — it doesn't exist
  • you're allergic to copper or have Wilson's disease
  • you're hoping for the GHK-Cu skin-collagen evidence — that's a different molecule with more data; read the GHK-Cu report
  • you can't separate your copper-peptide step from low-pH actives (vitamin C, AHA/BHA at pH 3–4) or from minoxidil applied to the same site — copper bonds break in acid and the copper itself can destabilize minoxidil; if you can't AM/PM-separate, the peptide won't do anything
First 90 days · AHK-Cu
Weeks 1–2
Tolerability check. Mild contact irritation or transient redness is normal for the first 1–2 weeks. Stop and patch-test if you get persistent dermatitis.
Weeks 4–8
Texture changes if it's going to work. Take a baseline photo at week 0 — week 8 vs baseline is the honest comparator. Your memory of how your skin looked is unreliable.
Week 12 — decide
Side-by-side photo decision. Cosmetic peptide effects are slow and modest. Anyone promising fast dramatic results is selling marketing, not skin biology.
Quit if
  • Persistent contact dermatitis or worsening irritation.
  • No perceived change in week 8 and week 12 photo comparisons (cosmetic peptides usually take longer than 12 weeks, but at 16 weeks if nothing has changed, the formulation isn't reaching the target).
  • Any pigmentation changes that persist after stopping.
Identity

What it is.

AHK-Cu is a tripeptide — alanine-histidine-lysine — bound to a single copper ion. It's the hair-and-scalp cousin of GHK-Cu, the better-known Loren Pickart . Both are copper-bound short peptides; AHK-Cu was developed and marketed specifically for follicle activity rather than skin.

The mechanism story: copper peptides modulate genes involved in hair-follicle dermal papilla cells, supporting the anagen (growth) phase, prolonging follicle lifespan, and possibly improving the local vascularization that hair growth depends on. It's sold mainly as a topical scalp serum, sometimes combined with minoxidil or other actives.

Like GHK-Cu, AHK-Cu has been studied in cosmetic dermatology for years. It's not as a hair-loss drug — that bar belongs to minoxidil and finasteride — but it is a legitimate cosmetic ingredient with a published research base.

TL;DR

TL;DR. 30-second version.

The compressed verdict — what AHK-Cu actually is, what the human evidence shows, and the watch-for in three bullets. Locked.

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Mechanism

Mechanism.

Mechanism · in the AHK-Cu report

How the molecule actually works — receptor profile, downstream signaling, what to expect mechanistically.

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Evidence

Evidence. What we actually know in humans.

Evidence · in the AHK-Cu report

The trial breakdown — phase, n, primary endpoint, who funded, what hit, what didn't.

Get the report · $19
Human-Evidence Factbox
Regulatory status
$19
Randomized human trials
$19
INCI to look for
$19
Authentic copper tell
$19
Head-to-head vs minoxidil
$19
Safety record (topical)
$19
Same as GHK-Cu?
$19
Stack conflict — low-pH actives
$19
Stack conflict — minoxidil co-apply
$19
Dose

Dose. The actual protocol.

Dose · in the AHK-Cu report

The specific protocol — dose, titration schedule, cycle pattern, frequency, route.

We read 2 studies to write this report.
Get the report · $19
Sourcing

Sourcing. Where the cohort actually buys.

Sourcing · in the AHK-Cu report

Sourcing breakdown — vendor methodology, red flags, our published test results, COA checklist.

We read 2 studies to write this report.
Get the report · $19
Safety

Safety. Side effects.

Safety · in the AHK-Cu report

The watch-for list — contraindications, drug interactions, monitoring labs, when to stop.

Get the report · $19
Editorial Position

Editorial position.

Editorial Position · in the AHK-Cu report

Our editorial position — explicit yes / no / depends, with the reasoning behind it.

Get the report · $19
The AHK-Cu Report · $19

Everything you need to start.

Dose, sourcing, safety, our verdict. One purchase. Yours forever.

Built from 2 cited studies.

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