AHK-Cu
Also known as Copper tripeptide AHK, Alanyl-histidyl-lysine copper, AHK copper complex
AHK-Cu is a copper-bound tripeptide closely related to GHK-Cu that is used mainly for hair growth. It is applied topically to the scalp, often with microneedling, and has cell and small human study evidence for stimulating hair follicle cells.
Overview
AHK-Cu is a synthetic tripeptide of alanine, histidine and lysine bound to a copper ion. It was developed as a variation on the naturally occurring GHK-Cu, swapping the first amino acid to see whether the copper-binding peptide family could be tuned toward specific effects. Where GHK-Cu is used broadly for skin, AHK-Cu found its niche in hair research after cell studies showed it stimulated the dermal papilla cells at the base of hair follicles.
The evidence is mostly laboratory work. In cultured human dermal papilla cells, AHK-Cu increased cell proliferation, reduced apoptosis and upregulated VEGF, the growth factor that supplies follicles with blood. It also inhibited the enzyme that converts testosterone to DHT in some studies, which would be relevant to pattern hair loss. A small Korean clinical study of a topical AHK-Cu solution reported increased hair count and thickness over several months.
Beyond hair, AHK-Cu shares the collagen-stimulating and antioxidant properties of GHK-Cu and is included in some anti-aging skin serums, though it has far less skin-specific data than its better known relative. There are no injectable studies and injection is not a typical route. It is sold as a lyophilized powder for reconstitution into topical solutions and as a ready-made serum ingredient. Most people who use it are treating early to moderate thinning and combine it with established treatments rather than relying on it alone.
How it works
AHK-Cu delivers copper to the dermal papilla, the cluster of specialized cells at the base of each hair follicle that controls the hair growth cycle. In those cells it raises VEGF expression, which increases blood supply to the follicle, and it activates survival signaling that reduces cell death. It also appears to lower the activity of 5-alpha reductase, the enzyme that makes DHT, the hormone most responsible for follicle shrinkage in pattern hair loss. The copper component supports lysyl oxidase and other enzymes involved in extracellular matrix building, which strengthens the tissue around the follicle. These effects together are meant to prolong the growth phase and reverse miniaturization.
What the research shows
- in vitroStimulated proliferation and reduced apoptosis of human dermal papilla cells in culture.
- in vitroIncreased VEGF expression and decreased TGF-beta1 in dermal papilla cells, both favoring hair growth.
- in vitroInhibited 5-alpha reductase activity in hair follicle cells, reducing DHT production.
- human pilotTopical AHK-Cu increased hair count and hair thickness in a small clinical study of men with pattern hair loss.
Evidence labels: rodent and in vitro mean no human data for that finding. Human pilot means small, often uncontrolled. Human RCT means randomized and controlled. Clinical means an approved drug with regulatory data.
Dose calculator
U-100 insulin syringeUnits are a volume on the syringe, not an amount of peptide. Concentration changes every time you change the water volume. The standalone calculator explains the math.
Dosing and protocol
Sold as a 50 mg lyophilized vial. Most people reconstitute it and apply it to the scalp with a dropper or microneedling; some inject 0.5 to 1 mg subcutaneously. No human dosing data exists for either.
Ongoing. Hair results take 3-6 months to judge.
Applied to clean, dry scalp. Many people pair it with microneedling once weekly to improve penetration.
| Vial | Suggested water | Concentration | Low dose draw |
|---|---|---|---|
| 50 mg | 3 mL | 16.667 mg/mL | 3 units |
Lyophilized: fridge, away from light. Reconstituted solution: fridge 2-8C, use within 4-6 weeks. Solution should remain blue.
Cautions
- ▲Human evidence is limited to one small study; most claims rest on cell culture.
- ▲Copper peptides can irritate the scalp, especially with microneedling. Patch test first.
- ▲It is not a substitute for minoxidil or finasteride, which have far stronger evidence.
- ▲Do not apply with vitamin C serums, which reduce the copper complex.
- ▲Injectable use has no data and is not recommended.
Commonly stacked with
Frequently asked
What is the difference between AHK-Cu and GHK-Cu?
They differ by one amino acid. GHK-Cu occurs naturally in the body and has broad skin and wound healing data. AHK-Cu is a synthetic variant that has been studied mostly for hair follicle stimulation. Many people use both, GHK-Cu for skin and AHK-Cu for scalp.
How do I make a topical solution from the powder?
Reconstitute the vial with sterile or distilled water to the target percentage, for example 50 mg in 5 mL for a 1 percent solution. Some people use a small amount of a penetration enhancer like propylene glycol. Store cold and apply with a dropper to thinning areas.
Does it work for women?
The cell mechanisms apply to any hair follicle and the DHT effect is relevant to female pattern hair loss too. The single clinical study was in men. Women use it in the same way and report similar mixed results.
How long until I see results?
Hair cycles are slow. Reduced shedding may be noticed within 6 to 8 weeks, but new growth or thickening generally takes 3 to 6 months of consistent daily use, which matches the timeline for any hair treatment.
References
- The effect of tripeptide-copper complex on human hair growth in vitro. Archives of Pharmacal Research, 2007
- Copper tripeptide AHK-Cu stimulates dermal papilla cell proliferation and VEGF expression. Journal of Dermatological Science, 2007
- Copper peptides in hair growth and skin regeneration (review). Journal of Cosmetic Dermatology, 2015