Copper Peptide AHK-Cu vs Acetyl Tetrapeptide-5
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: Tripeptide-3, Ala-His-Lys Copper
AHK-Cu is a synthetic copper-bound tripeptide, alanine-histidine-lysine complexed with a copper ion, engineered mainly for hair and scalp products. It is the lesser-known sibling of the naturally occurring GHK-Cu copper peptide, designed in the lab specifically to push hair follicles to keep growing. It is a cosmetic and research ingredient, not an approved hair-loss drug, and its evidence is essentially limited to one notable lab study.
Also: Eyeseryl, Ac-beta-Ala-His-Ser-His
Acetyl tetrapeptide-5 is a short synthetic peptide sold by Lipotec (now Lubrizol) as Eyeseryl, made for eye creams that target under-eye puffiness. The pitch is that it reduces fluid leaking into the tissue under the eyes. It is a cosmetic ingredient, and nearly all of the human data comes from the company that sells it.
Key Comparison Insights
- Both peptides belong to the Skin & Hair category, suggesting similar primary applications.
Detailed Comparison
| Attribute | Copper Peptide AHK-Cu | Acetyl Tetrapeptide-5 |
|---|---|---|
| Category | Skin & Hair | Skin & Hair |
| FDA Status | Not FDA Approved | Not FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | Copper peptides like AHK-Cu are thought to act as carriers and signals for copper, a metal involved in tissue repair, blood vessel growth and collagen remodeling. In hair, the proposed action centers on dermal papilla cells, the control hub at the base of each follicle that orchestrates the growth cycle. AHK-Cu is hypothesized to keep those cells alive and dividing longer, partly by shifting the balance of survival proteins (more Bcl-2, less Bax) so follicle cells are less likely to enter programmed cell death, which would extend the active growth phase. These are mechanisms observed in cells and isolated follicles, not proven outcomes in people growing hair. | The peptide is acetyl-beta-alanine-histidine-serine-histidine. The manufacturer's lab work claims three effects: it reduces vascular permeability (less fluid seeping out of small blood vessels, tested in an endothelial cell model), it inhibits glycation (sugar damage to proteins like collagen), and it has some ACE-inhibiting activity that is linked to fluid balance. All of that is in vitro and company-generated. An important reality check: under-eye bags have several causes, and a lot of them in older adults come from fat pads pushing forward and loose skin, not fluid. A peptide aimed at fluid cannot touch fat-pad bags, so even in the best case it fits morning puffiness better than structural eye bags. |
| Common Dosing | Limited community data available See research protocols | 1% of the Eyeseryl solution in an eye cream Twice daily |
| Administration | Topical (scalp serums, solutions) | Topical (eye creams, gels, serums) |
| Typical Duration | 3-6 months for visible results | 28-60 days in manufacturer studies; ongoing use to maintain any effect |
| Best Time to Take | Morning or as directed | Morning and evening, gently patted under the eyes |
Possible Side Effects May vary by individual |
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| Research Summary | The science here is real but narrow. The anchor study is Pyo and colleagues, published in Archives of Pharmacal Research in 2007, which tested AHK-Cu on human hair follicles and dermal papilla cells outside the body. At very low concentrations it significantly lengthened isolated human hair follicles and increased dermal papilla cell proliferation, while reducing apoptosis markers, and notably the effect followed a tight dose-response curve where higher concentrations stopped working. That is genuine peer-reviewed evidence for a biological effect. What does not exist is the part people actually want: randomized controlled human trials showing that applying AHK-Cu to a scalp regrows hair or thickens it in living people. So the honest read is that AHK-Cu has a plausible mechanism and one credible ex vivo and in vitro study behind it, but its real-world hair-growth benefit in humans is unproven, and most consumer claims extrapolate well beyond what that single study supports. | We could not find an independent, peer-reviewed clinical trial of acetyl tetrapeptide-5. The evidence is manufacturer data reported in trade publications. Lipotec's best-known study used a 1% Eyeseryl cream on one eye and placebo on the other in male volunteers aged 30 to 65, twice daily for 28 days, and reported about a 30% reduction in under-eye puffiness volume, with most volunteers rating it positively. Another supplier document describes a 60-day study in 20 women using a cream with a very low peptide level, scored from photos by a dermatologist. Other summaries quote different numbers (17% to 21%) from studies we could not trace to an original paper. The studies differ in concentration, sex, length and how puffiness was measured, so they cannot be pooled. Independent ingredient databases rate the evidence as limited for exactly this reason. Bottom line: plausible for mild fluid puffiness, cheap to try in an eye cream, but not a fix for true eye bags and not backed by independent trials. |
Frequently Asked Questions: Copper Peptide AHK-Cu vs Acetyl Tetrapeptide-5
What is the difference between Copper Peptide AHK-Cu and Acetyl Tetrapeptide-5?
Copper Peptide AHK-Cu is a skin & hair peptide that ahk-cu is a synthetic copper-bound tripeptide, alanine-histidine-lysine complexed with a copper ion, engineered mainly for hair and scalp products. it is the lesser-known sibling of the naturally occurring ghk-cu copper peptide, designed in the lab specifically to push hair follicles to keep growing. it is a cosmetic and research ingredient, not an approved hair-loss drug, and its evidence is essentially limited to one notable lab study. Acetyl Tetrapeptide-5 is a skin & hair peptide that acetyl tetrapeptide-5 is a short synthetic peptide sold by lipotec (now lubrizol) as eyeseryl, made for eye creams that target under-eye puffiness. the pitch is that it reduces fluid leaking into the tissue under the eyes. it is a cosmetic ingredient, and nearly all of the human data comes from the company that sells it. The main differences lie in their mechanisms of action and clinical applications.
Which is better, Copper Peptide AHK-Cu or Acetyl Tetrapeptide-5?
Neither is universally "better" - the choice depends on your specific goals. Copper Peptide AHK-Cu is typically used for skin & hair purposes, while Acetyl Tetrapeptide-5 is used for skin & hair. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can Copper Peptide AHK-Cu and Acetyl Tetrapeptide-5 be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Copper Peptide AHK-Cu and Acetyl Tetrapeptide-5 together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.