AHK-Cu
GHK-Cu's synthetic cousin, one residue different, same copper habit. Its entire independent evidence base is a single study from 2007.
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For research use only. Not for human or veterinary use.
What AHK-Cu is
The plain-language version, first.
One letter away from a famous molecule, and a whole reputation borrowed from it.
AHK-Cu is a peptide-copper coordination complex of the synthetic tripeptide Ala-His-Lys, structurally distinct from GHK-Cu by a single alanine-for-glycine substitution at position one. The free peptide is C15H26N6O4 with molecular weight 354.41 (CAS 126828-32-8) and the monohydrochloride copper complex is C15H24ClCuN6O4 with molecular weight 451.39 (CAS 682809-81-0). Its published evidence consists of a single study reporting human hair follicle elongation ex vivo and dermal papilla cell proliferation at picomolar to nanomolar concentrations, with no registered human trials.
Change one residue in a three-residue peptide and you have changed a third of the molecule. Worth remembering when something is marketed as a close cousin.
It is alanine-histidine-lysine holding a copper ion. Its famous relative GHK-Cu is glycine-histidine-lysine doing the same.
The histidine-lysine copper grip is shared, which is the part that matters for the chemistry: both are small peptides whose job description involves carrying copper.
GHK-Cu has decades of literature, a discovery story in human plasma, and a name in dermatology research.
AHK-Cu has the resemblance.
One-third different, marketed as basically the same, and the difference between their bibliographies is the entire story.
What is AHK-Cu?
Mechanism studied, not outcome promised.
AHK-Cu is a coordination compound. The free tripeptide Ala-His-Lys (C15H26N6O4, 354.41, CAS 126828-32-8) and the monohydrochloride copper complex (C15H24ClCuN6O4 anion, 451.39, CAS 682809-81-0) are different species with different weights.
GHK is Gly-His-Lys, identified in 1973 as an activity in human albumin. AHK replaces the position one glycine with alanine. GHK is the natural molecule and AHK is the synthetic analogue.
The only real study reported effects from ten to the minus twelve to ten to the minus nine molar on human hair follicle elongation and dermal papilla cell proliferation (Pyo, 2007, PMID 17703734).
Copper delivery, same as its cousin, with less proof it matters.
The proposed mechanism is copper logistics, same as the cousin.
Copper is a cofactor for enzymes involved in collagen cross-linking and vessel formation, and small copper-binding peptides are studied as delivery vehicles for it.
For GHK-Cu that proposal has decades of supporting work. For this one it has an assumption of family resemblance.
Does the swapped residue change binding, delivery, or activity? Genuinely unknown, because the comparative work does not exist.
Here's the honest part, and it applies to every cousin-molecule on the market.
Resemblance is a hypothesis. In chemistry, one changed letter has rewritten plenty of stories.
The research so far for AHK-Cu
Where the evidence is thin, we say so.
One study. AHK-Cu at ten to the minus twelve to ten to the minus nine molar stimulated elongation of human hair follicles ex vivo and proliferation of dermal papilla cells in vitro (Pyo, 2007, Archives of Pharmacal Research, PMID 17703734). Well defined coordination chemistry for both the free peptide and the monohydrochloride copper complex.
Registered human trials, of which there are none. Independent replication of the 2007 work could not be found either. Nothing demonstrates that swapping glycine for alanine at position one preserves GHK's biology, which is the assumption most AHK-Cu writing quietly runs on. The roughly 417 molecular weight figure some listings print is also unconfirmed against any primary source.
The single published study on AHK-Cu reports activity between ten to the minus twelve and ten to the minus nine molar, a range that is scientifically meaningful because effects at that occupancy indicate receptor-level or signalling recognition rather than a bulk chemical action. The same figure undermines the way concentration is usually discussed for this compound, because a percentage printed on a topical formulation describes the amount applied to a surface and says nothing about the molar concentration reaching a follicle, and no published work bridges those two quantities for AHK-Cu. The result is that the most quantitatively precise thing known about the molecule is also the thing that makes most claims about it very difficult to test in practice.
One study. 2007. Hair follicles in a dish. That is the file.
The independent file, in full: one study, 2007, examining hair follicle cells in vitro.
That is not an exaggeration for effect. One dedicated published study.
Everything else written about it is GHK-Cu work wearing a different name tag, and the swap is almost never disclosed.
No animal outcome studies of its own worth the name. No human trials. Nothing approved.
A single 2007 paper and a famous cousin. When a compound's bibliography fits in one sentence, the sentence should at least be accurate, and this one now is.
AHK-Cu, research grade, sold for laboratory use only.
AHK-Cu specs
The chemistry, exactly as released.
Who studies AHK-Cu
Who tends to order this one, and why.
A research compound does not have one audience. It has a handful of rooms where the same question keeps coming up, and the question is a different question in each of them.
Copper peptide chemists
A three residue chelation site built around a histidine imidazole is a compact and well behaved model complex, and both the free peptide and the monohydrochloride complex are characterised.
Hair follicle researchers
The Pyo ex vivo follicle elongation model is the only published context for this compound, and it remains unreplicated independently.
Structure-activity groups working on GHK
AHK is the cleanest available single-residue variant of GHK, which makes it useful for asking what position one actually contributes.
Anyone reading a topical concentration claim
The published active range is picomolar to nanomolar. Nothing published connects that to a percentage on a label, which is worth knowing before comparing products.
Sold for laboratory research only. This is not guidance for personal use, and nothing here is a recommendation.
AHK-Cu backstory
How it got here.
1973 is the year to start with, and it isn't AHK's year. A group looking at human albumin found an activity in it and eventually pinned it to three amino acids, glycine, histidine and lysine.
GHK. It picked up copper, it picked up a reputation, and fifty years later it's in cosmetics, in wound literature and in regulatory documents.
AHK came later and came from a chemist's question rather than from a body. What happens if you change position one?
Alanine is glycine with a methyl group. It's the smallest change you can make to that position and still change something.
The resulting molecule is synthetic, has no natural source, and carries a literature about the size of a single paper. That's a strange place for a compound to sit.
Famous by association, studied almost not at all.
- 1
GHK came first, in 1973
Gly-His-Lys was identified as an activity in human albumin and became one of the most studied copper-binding peptides in biology.
- 2
AHK is the synthetic answer to a question
Replace the position one glycine with alanine, which is glycine plus a methyl group, and see what changes. AHK has no natural source.
- 3
One paper, 2007
Pyo and colleagues reported ex vivo human hair follicle elongation and dermal papilla cell proliferation at picomolar to nanomolar concentrations. The literature has not grown much since.
Buying AHK-Cu in Canada
What ships, how fast, and the paperwork.
The hard part of buying research material is almost never the compound. It is the logistics. What leaves the building, how fast it moves, and what is in the box beside the vial. Here is ours, plainly.
Research use only, and a regulatory contrast worth knowing
Sold for laboratory research use only, not for human or veterinary consumption. GHK-Cu appears on FDA 503A Category 1, under evaluation, except for injectable routes, and GHK-Cu is named in Health Canada's advisory of 9 April 2026, which states that peptides are generally regulated as prescription drugs in Canada and that "For Research Use Only" labelling does not make these products legal. AHK-Cu is on neither list, because it has not reached the stage of being evaluated. Absence is not approval.
Ask which molecular weight you are being quoted
The free peptide is 354.41 and the monohydrochloride copper complex is 451.39. A single number with no form named is not usable information. The figure near 417 that circulates on vendor listings could not be confirmed against a primary source.
Most AHK-Cu writing is really about GHK
The two differ at position one. GHK has five decades of literature and AHK has approximately one paper. Claims transferred from one to the other are assumptions, not findings.
AHK-Cu vs GHK-Cu
Stacked together constantly, compared almost never.
This is the comparison the whole page has been circling, so here it is straight.
AHK-Cu shares the copper grip and one-third of its sequence is different. Its independent evidence base is a single 2007 in-vitro study.
GHK-Cu was found in human plasma in 1973 and carries decades of literature, including the 1994 wound-setting trial and one blinded aesthetic null.
If the evidence is what you are buying, buy the molecule the evidence is about. They sit on the same shelf and only one of them wrote the file. GHK-Cu has its own page here
Stuff people ask about AHK-Cu
If your question is not here, email us. Real human answers.
One amino acid. GHK is Gly-His-Lys and AHK is Ala-His-Lys, so position one carries an alanine instead of a glycine, which is a single methyl group of difference. GHK is the natural peptide, identified in 1973 as an activity in human albumin. AHK is a synthetic analogue with no natural source and a far smaller literature behind it.
It depends which form you mean, and that's not a dodge. The free tripeptide Ala-His-Lys is C15H26N6O4 at 354.41 daltons, CAS 126828-32-8. The monohydrochloride copper complex is C15H24ClCuN6O4 as an anion at 451.39 daltons, CAS 682809-81-0. A figure around 417 circulates on vendor listings and we could not confirm it in any primary source.
One study of substance. Pyo and colleagues in 2007 reported that AHK-Cu at ten to the minus twelve through ten to the minus nine molar stimulated elongation of human hair follicles ex vivo and proliferation of dermal papilla cells in vitro (Archives of Pharmacal Research, PMID 17703734). There are no registered human trials. Most other writing about AHK-Cu is inference from GHK.
Because AHK-Cu is a coordination complex rather than a peptide that happens to have copper nearby. The histidine imidazole ring makes a tripeptide with histidine in the middle an efficient copper handle, and the complex is the species that was studied. Treating the free peptide and the copper complex as the same material is the most common error made with this compound.
That the effect observed was a signalling event rather than a bulk chemical one, since ten to the minus twelve molar is far too low for a structural mechanism. It also makes topical concentration claims difficult to interpret, because nothing published connects a percentage in a formulation to a molar concentration at a hair follicle. Precision in the study, ambiguity on the label.
Because GHK-Cu's reputation carries. The two molecules differ by a single residue, GHK has five decades of literature behind it, and the assumption that AHK behaves the same way is easy to make and rarely stated out loud. The one AHK-Cu study that exists is a 2007 ex vivo follicle model, and it hasn't been independently replicated as far as we can find.
Good pairing options with AHK-Cu
What researchers stack alongside it.
Pairing is where research gets ahead of itself. These are the compounds researchers put in the same order as AHK-Cu, which is a statement about ordering habits, not about evidence. Two things in one cart have not been studied together unless somebody studied them together.
Without a zinc atom it is completely inert. Not less active. Inert. The metal is not a supporting player here, it is half the molecule's identity.
It has no sequence and no CAS number, because it is not a molecule. It is an extract of calf thymus, still in clinical use across Russia, and that combination is genuinely unusual.
Order AHK-Cu right now
One last look before you decide.
Freeze-dried, COA on the page, ships cold
If you are researching AHK-Cu and you want a source you do not have to second-guess, start with the paperwork on this page. For research use only.
Not for human consumption. Not approved by Health Canada or any other regulatory body.
Page last updated August 19, 2026
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