AHK-Cu vs GHK-Cu

AHK-Cu and GHK-Cu are both copper peptides discussed for skin and hair, and neither is approved as a drug. GHK-Cu has many more studies, mostly in animals and lab cells with a few small studies in people, while AHK-Cu has only lab results so far. This page compares their results.

Best randomized result by outcome

For each outcome that two or more peptides have results for: the best result of a single randomized trial, on the same measure (the same kind of number, the same unit). When a trial has several dose arms, the cell shows the highest dose arm. The trials differ in people, length and dose, so a gap between two cells is not proof that one peptide works better.

No outcome has a randomized-trial result on the same measure for two or more of these peptides yet.

Comparing 2 peptides · Data version 308560

Only differences

Swipe sideways to see every peptide.

Comparison of AHK-Cu (Ala-His-Lys copper complex), GHK-Cu
Peptide	Metal complex AHK-Cu (Ala-His-Lys copper complex)	Metal complex GHK-Cu
Identity
Kind	Metal complex	Metal complex
Area	Skin and hair	Recovery and repair
Evidence
Amount of evidence	6	226 (plus 7 on natural levels, listed separately)
Evidence level	Results from lab studies only	Has results from studies in people
Safety
Safety results	No safety results	5 (0 in people)
Status
Approval
Sport (WADA)
Registered trials	None registered	1 · 1 active2 more mention it but do not test it

Shared outcomes

Skin and hair20

Approval and sport status

From the regulatory data of each peptide.

AHK-Cu (Ala-His-Lys copper complex)
The FDA, the EMA and the other sources we use show no approval (as of 21 Oct 2026).
GHK-Cu
Its most advanced trial is in phase 2. The FDA, the EMA and the other sources we use show no approval (as of 8 Oct 2026).

Amount of evidence by outcome

Outcome groups with study results for at least two of these peptides. Counts include only results from studies that gave the peptide. Bar length is the number of results, on one scale. The bars show how much was studied, not how large an effect was. A peptide with more studies can look stronger here without being stronger. For results, see the randomized results above.

Study results per shared outcome group and evidence class
Outcome group	AHK-Cu (Ala-His-Lys copper complex)	GHK-Cu
Skin and hairSkin and wound	66	1477

Sequence alignment

Each analog against its native parent, residue by residue. Substitutions, non-standard residues and modifications are marked. Calculated from the two sequences.

Against GHK (glycyl-L-histidyl-L-lysine; prezatide)GHK-Cu

GHK-Cu is the same as GHK (glycyl-L-histidyl-L-lysine; prezatide) residues 1 to 3.

Top row: GHK (glycyl-L-histidyl-L-lysine; prezatide) (parent)
Bottom row: GHK-Cu

GHK

Same as parent
Substituted
Non-canonical or D-form
Modified side chain or end

No differences in the aligned region.

Trials side by side

Registered trials, ranked by phase (late phases first), then posted results and enrollment. Status is the registry status. Study results come from published studies. Results posted at ClinicalTrials.gov are shown on each trial page.