GHK-Cu vs AHK-Cu

Two copper peptides that differ by one amino acid: one for skin, one sold for hair

By MoveWell Research Team Updated November 1, 2026

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Which one for what

For skin, GHK-Cu: it has small human trials and AHK-Cu has none. For scalp hair, neither has human evidence; GHK-Cu has only one small eyebrow trial. Neither wins.

  • Wrinkles and firmness: GHK-Cu
  • Hair thinning: no winner
  • Wounds: GHK-Cu
  • Injury or injection: neither
2D structure of GHK-Cu: glycine, histidine and lysine bound to a copper ion
GHK-CuGly-His-Lys + copper. Found in human bloodGHK-Cu guide
2D structure of AHK-Cu: alanine, histidine and lysine bound to a copper ion
AHK-CuAla-His-Lys + copper. Lab-made variantAHK-Cu guide
In this guide
  1. Verdict
  2. At a glance
  3. Evidence by goal
  4. Key differences
  5. Can you use both?
  6. Where to get each
  7. FAQ
  8. References

At a glance

GHK-CuAHK-Cu
What it isGlycine, histidine and lysine bound to one copper ion. Found in human blood in 1973; products are synthetic1The same peptide with alanine in place of glycine, bound to copper. A lab-made variant developed for hair2, 3
StatusCosmetic ingredient. Topical GHK-Cu is in FDA's Category 1, so licensed pharmacies can compound it. Injectable GHK-Cu has no compounding path11Cosmetic ingredient. Not on FDA's published 503A category lists, so pharmacies have no clear basis to compound it11
Evidence3/5Limited human, for skin only2/5Lab only, for hair
Main useSkin: fine lines and firmnessHair and scalp
FormCosmetic serums and creams (label name: copper tripeptide-1); compounded prescription creamsHair and scalp serums at 1% to 8%, often mixed with GHK-Cu
Typical cost$23 to $69 for a cosmetic serumUnverified; from $55 per 30 g compounded18About US$50 to $229 per serum19, 20
Main risksSkin irritation. A safety panel found it safe at cosmetic strengths. Injected: unknown; FDA flags immune reactions and impurities10, 12Unknown. No published safety, irritation or allergy testing found. The cosmetic safety review did not cover it10

Evidence scale: 5 FDA-approved, 4 strong human, 3 limited human, 2 animal or lab only, 1 anecdotal. Cosmetic serum prices for GHK-Cu could not be rechecked on brand sites. Currency conversions for AHK-Cu serums are approximate.

Evidence by goal

Each goal is graded separately for each peptide. "No study found" means none turned up in the sources we reviewed.

GoalGHK-CuAHK-Cu
Wrinkles and firmness (on skin)3/51 published trial in 40 women: wrinkle volume down 55.8% vs plain serum at 8 weeks, plus conference abstracts4, 51/5None found. Skin claims borrow from GHK-Cu studies
Hair growth1/5No GHK-Cu scalp-hair trial found. A 45-man trial used a copper-free GHK complex with 5-ALA, so it tests neither peptide9. One small 2026 randomized split-face eyebrow trial (n=18) of 2% GHK-Cu reported more hairs on the treated side252/51 lab study of human follicles in a dish, plus unpublished mouse data in a patent8, 3
Wound healing3/51 trial in diabetic foot ulcers (1994), with gel on the wound6No study found
Tendon or ligament2/51 rat study; the benefit was gone by 12 weeks7No study found
Injected use2/5Animal and lab only. No human study of any injected doseNo study found

The two have never been compared head to head. Much of GHK-Cu's human skin evidence comes from older studies, possibly industry-linked, that are known mainly from conference abstracts.5

Key differences

  • One amino acid apart. AHK-Cu has alanine where GHK-Cu has glycine, which adds one small carbon group. The end that holds the copper is the same.2
  • Natural vs lab-made. GHK was found in human blood in 1973.1 AHK-Cu was made by ProCyte, whose patent describes it as a hair-growth agent.3 Both are made synthetically for products.
  • Who has human data. GHK-Cu has small human trials for skin and wounds.4, 6 AHK-Cu has none. Its evidence is one lab study on follicles in a dish.8
  • The hair-study mix-up. The follicle study often cited for GHK-Cu actually tested AHK-Cu.8 So GHK-Cu has no scalp-hair evidence of its own, only one small 2026 eyebrow trial (n=18),25 and AHK-Cu has only that lab result.
  • More isn't clearly better. In the AHK-Cu lab study, follicles grew at very low concentrations and were held back at higher ones.8 Retail serums are far stronger than the range tested.
  • Safety record. A cosmetic safety panel reviewed GHK-Cu and found it safe at cosmetic strengths. AHK-Cu was not part of that review, and we found no safety testing for it.10
  • Regulation. Topical GHK-Cu can be compounded by licensed pharmacies, and FDA's advisory committee plans to review injectable GHK-Cu before the end of February 2027.11, 13 GHK-Cu was not part of the October 2026 HHS policy for six other peptides.14 AHK-Cu isn't on any published FDA compounding list.11

Can you use both?

Rationale onlyNot tested together

It's the most common pairing in hair serums, such as Neurogan (equal amounts) and Hairgenetix (5% AHK-Cu, 10% GHK-Cu). Neurogan says no controlled human trial has tested the combination;15 Hairgenetix says the trials it cites studied the ingredients, not its product.16 Neither peptide has human scalp-hair data on its own (GHK-Cu has one small eyebrow trial25), so a blend adds an untested ingredient to another untested one. Minoxidil and finasteride are the hair-loss treatments with human trials and FDA approval.24

See the AHK-Cu + GHK-Cu hair stack or browse all stacks.

Where to get each

MoveWell sells no peptides. Prices as checked November 1, 2026

PeptideOptionFormPriceNotes
GHK-CuSuperpower0.5% GHK-Cu cream, compoundedMembers only ($17/mo membership, billed annually); product price not shown17Questionnaire and physician review
GHK-CuTrinova HealthCompounded cream with GHK-Cu, hydroquinone, vitamin C and kojic acidFrom $55 per 30 g18Online evaluation
GHK-CuCosmetic serumsSerums and creams; many don't state strength$23 to $69UnverifiedCompare 8 serums in our GHK-Cu guide
AHK-CuNeurogan AHK-Cu Hair Serum8% AHK-Cu, 60 mL$22919Strongest stated strength we found
AHK-CuNubeean Noosa Scalp Serum1% AHK-Cu, 30 mLAUD 7520Also contains MSM and trehalose
BothNeurogan AHK + GHK Hair Serum Pro2.4 g of each per 60 mL$18515The combination is untested

Left off: injectable GHK-Cu, which has no compounding path, and "research use only" vials of either peptide, which aren't made or tested for people. More options in the GHK-Cu and AHK-Cu guides.

FAQ

Which is better for hair loss?

Neither has been shown to work in people. AHK-Cu has one lab study on follicles in a dish; GHK-Cu has no scalp-hair study of its own; one small 2026 eyebrow trial (n=18) reported more hairs on the treated side.25 Minoxidil and finasteride are the options with human trials.24

Which is better for skin?

GHK-Cu. It has a 40-person randomized trial and older studies, known mainly from conference abstracts, showing modest gains over 8 to 12 weeks. We found no skin study of AHK-Cu.

Are they the same thing?

Nearly. They differ by one amino acid, alanine in AHK-Cu and glycine in GHK-Cu. They have never been compared head to head, so whether that change matters in people is unknown.

What do the label names mean?

Copper tripeptide-1 is GHK-Cu. AHK-Cu usually appears as copper tripeptide-3 on product labels. "Tripeptide-3" without copper is a different, unrelated ingredient.21, 22

Is a stronger serum better?

Not necessarily. In the only AHK-Cu study, the benefit appeared at tiny concentrations and reversed at higher ones. No one has tested strengths on a scalp.

Are they legal?

Both are sold legally as cosmetic ingredients. Topical GHK-Cu can also be compounded by licensed pharmacies. Injectable GHK-Cu has no compounding path; an advisory committee vote alone wouldn't create one, which takes a rule or a policy like the October 2026 HHS one.23 AHK-Cu isn't on any published compounding list.

References

25 sources, with links
  1. Pickart L, Thaler MM. Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Nature New Biology 1973;243:85–87. Record
  2. ChEBI 158225, Ala-His-Lys. EBI
  3. ProCyte Corp. US Patent 6,017,888, Stimulation of hair growth by peptide copper complexes. Google Patents
  4. Badenhorst T et al. Effects of GHK-Cu on MMP and TIMP expression, collagen and elastin production, and facial wrinkle parameters. J Aging Sci 2016;4:166. DOI 10.4172/2329-8847.1000166
  5. Pickart L, Vasquez-Soltero JM, Margolina A. GHK peptide as a natural modulator of multiple cellular pathways in skin regeneration. BioMed Res Int 2015:648108. Describes the Leyden, Finkley and Abdulghani studies. PMC4508379
  6. Mulder GD et al. Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-l-histidyl-l-lysine copper. Wound Repair Regen 1994;2:259–69. DOI
  7. Fu SC et al. Tripeptide-copper complex GHK-Cu (II) transiently improved healing outcome in a rat model of ACL reconstruction. J Orthop Res 2015. DOI 10.1002/jor.22831
  8. Pyo HK et al. The effect of tripeptide-copper complex on human hair growth in vitro. Arch Pharm Res 2007;30(7):834–9. DOI 10.1007/BF02978833. Tested AHK-Cu. Record
  9. Lee WJ et al. Efficacy of a complex containing GHK and 5-aminolevulinic acid on hair growth in men with androgenetic alopecia. Ann Dermatol 2016;28(4):438–43. Copper-free. PMC4969472
  10. Johnson W et al. Safety assessment of tripeptide-1, hexapeptide-12, their metal salts and fatty acyl derivatives, and palmitoyl tetrapeptide-7 as used in cosmetics. Int J Toxicol 2018;37(3 suppl):90S–102S. Link
  11. FDA. Bulk drug substances nominated for use in compounding under 503A, categories list (updated May 14, 2026). fda.gov
  12. FDA. Certain bulk drug substances for use in compounding that may present significant safety risks. fda.gov
  13. FDA. Meeting of the Pharmacy Compounding Advisory Committee (before end of Feb 2027). fda.gov
  14. BakerHostetler. HHS issues enforcement discretion policy regarding 503A compounding using certain peptide bulk drug substances (Oct 28, 2026). Link
  15. Neurogan Health. AHK-Cu + GHK-Cu Hair Serum Pro (product page and evidence statement). Link
  16. Hairgenetix. Copper Peptide Hair Growth Serum (product page and evidence statement). Link
  17. Superpower. GHK-Cu cream. Link
  18. Trinova Health. Reju cream. Link
  19. Neurogan Health. AHK-Cu Copper Peptide Hair Serum 4800mg. Link
  20. Nubeean Noosa. Copper Peptide AHK-Cu Scalp Serum. Link
  21. EU CosIng, copper tripeptide-1, ref 55687 (via mirror). Link
  22. CosIng mirror, tripeptide-3 (a different ingredient). Link
  23. Holland & Knight. Peptides at a crossroads: what wellness providers need to know (Oct 16, 2026). Link
  24. Springer K, Brown M, Stulberg DL. Common hair loss disorders. Am Fam Physician 2003;68(1):93–102. AAFP
  25. Bo SL, Nararatwanchai T, Suppornpun N, Poomarapan K, Thaploka S. The efficacy of 2% copper peptide (GHK-Cu) serum for eyebrow hypotrichosis (vehicle-controlled, split-face). Procedia of Multidisciplinary Research 2026;4(5). Link

This page is for education and is not medical advice. Neither GHK-Cu nor AHK-Cu is FDA-approved as a drug. Talk to a clinician about hair loss or skin concerns before starting any treatment.