GHK-Cu vs Acetyl Tetrapeptide-5
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: Copper Peptide, Glycyl-L-histidyl-L-lysine copper
GHK-Cu is the copper(II) complex of GHK, a naturally occurring human tripeptide (glycyl-L-histidyl-L-lysine) found in blood plasma, saliva and urine, whose levels decline with age. It is researched and widely used in cosmetic skincare for skin regeneration, wound healing, collagen support and anti-aging. It is not an FDA-approved drug; it appears in over-the-counter cosmetics and as a research or compounded peptide, with most human evidence coming from small topical-skincare studies.
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.
- GHK-Cu has stronger research evidence (Human Trials) compared to Acetyl Tetrapeptide-5 (Limited Research).
Detailed Comparison
| Attribute | GHK-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 | GHK has a strong affinity for copper(II) ions and forms the GHK-Cu complex, which is thought to deliver copper to cells for copper-dependent processes such as connective-tissue formation and antioxidant defense. Its most striking documented activity is broad gene-expression modulation: in cultured human cells, GHK shifts the expression of a large fraction of genes, tending to upregulate tissue-repair genes and downregulate some inflammatory pathways. It stimulates fibroblasts to produce collagen and other extracellular-matrix proteins, supports keratinocyte and blood-vessel activity, and shows antioxidant and anti-inflammatory effects in lab models. Importantly, the copper-binding hypothesis does not fully explain these gene effects, and researchers note the precise mechanism is not yet fully understood. | 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 | 1-2 mg daily systemically, or 0.05% in cosmetic formulations Once daily | 1% of the Eyeseryl solution in an eye cream Twice daily |
| Administration | Subcutaneous injection or topical application | Topical (eye creams, gels, serums) |
| Typical Duration | Varies by application | 28-60 days in manufacturer studies; ongoing use to maintain any effect |
| Best Time to Take | Evening (for skin/recovery) | Morning and evening, gently patted under the eyes |
Possible Side Effects May vary by individual |
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| Research Summary | Much of the mechanistic and efficacy evidence is from cell culture and animal studies. In animals, GHK and GHK-containing dressings improved wound contraction, granulation tissue and collagen deposition in rabbit and rat wounds, and showed protective effects in lung-injury models. In cells, GHK increases collagen, elastin and growth-factor production by fibroblasts and protects keratinocytes from UV damage. Human evidence exists but is limited to small cosmetic trials: facial-cream and eye-cream studies in modest numbers of women (for example a 71-subject facial study and a 41-subject eye-cream study) reported improvements in skin density, thickness and wrinkle appearance. These trials are small and focused on topical skin endpoints, so they do not establish injected or systemic benefits, and there are no large independent randomized trials. Honest summary: strong lab and animal data plus encouraging small topical human studies, but evidence for injected use is preliminary. | 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: GHK-Cu vs Acetyl Tetrapeptide-5
What is the difference between GHK-Cu and Acetyl Tetrapeptide-5?
GHK-Cu is a skin & hair peptide that ghk-cu is the copper(ii) complex of ghk, a naturally occurring human tripeptide (glycyl-l-histidyl-l-lysine) found in blood plasma, saliva and urine, whose levels decline with age. it is researched and widely used in cosmetic skincare for skin regeneration, wound healing, collagen support and anti-aging. it is not an fda-approved drug; it appears in over-the-counter cosmetics and as a research or compounded peptide, with most human evidence coming from small topical-skincare studies. 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, GHK-Cu or Acetyl Tetrapeptide-5?
Neither is universally "better" - the choice depends on your specific goals. GHK-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 GHK-Cu and Acetyl Tetrapeptide-5 be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using GHK-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.