Acetyl Tetrapeptide-5 vs Nonapeptide-1
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
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.
Also: Melanostatine 5, Melanostatine-5
Nonapeptide-1, sold as Melanostatine 5, is a nine-amino-acid synthetic peptide built to block alpha-MSH, the hormone that tells pigment cells to make melanin. It goes into brightening and dark-spot products as a gentler alternative to harsh lighteners. It is a cosmetic ingredient, not an FDA-approved drug, and there is no independent peer-reviewed clinical trial of it on its own.
Key Comparison Insights
- Both peptides belong to the Skin & Hair category, suggesting similar primary applications.
Detailed Comparison
| Attribute | Acetyl Tetrapeptide-5 | Nonapeptide-1 |
|---|---|---|
| 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 | 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. | When skin is hit by UV, it releases alpha-MSH, which binds the MC1R receptor on melanocytes and switches on tyrosinase, the enzyme that makes melanin. Nonapeptide-1 is designed to sit in that receptor without switching it on, a competitive antagonist, so less of the tanning and pigment signal gets through. In cell studies it binds MC1R with high affinity and blocks alpha-MSH-driven melanosome dispersion at nanomolar levels, and it lowered tyrosinase and related pigment genes in human melanocytes. It is essentially the opposite of melanotan I and afamelanotide, which activate the same receptor to darken skin. The big unknown, as with most cosmetic peptides, is how much reaches melanocytes through intact skin. |
| Common Dosing | 1% of the Eyeseryl solution in an eye cream Twice daily | Low percentage in a brightening serum Once or twice daily |
| Administration | Topical (eye creams, gels, serums) | Topical (serums, creams) |
| Typical Duration | 28-60 days in manufacturer studies; ongoing use to maintain any effect | Brightening claims are usually judged over 8 to 12 weeks; ongoing use |
| Best Time to Take | Morning and evening, gently patted under the eyes | Morning (under sunscreen) and/or evening |
Possible Side Effects May vary by individual |
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| Research Summary | 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. | The evidence is thin and mostly commercial. Receptor binding and anti-pigment effects come from cell work and supplier data sheets. In a 2022 paper in Postepy Dermatologii i Alergologii (Chen and colleagues), nonapeptide-1 was used as a reference MC1R blocker in UVA-exposed human melanocytes and keratinocytes, where it reduced pigment pathway activity, but the study's focus was tea polyphenols, not the peptide. Ingredient databases describe the human data as small and manufacturer-generated. You will see claims online of a 12-week, 40-person trial where a cream with this peptide matched 4 percent hydroquinone for melasma, but we could not find a published, citable version, and even then it was a multi-ingredient cream. Fair summary: a well-designed molecule with a clear mechanism in cells, and very little real-world proof. Sunscreen still does more for dark spots than any single brightening peptide. |
Frequently Asked Questions: Acetyl Tetrapeptide-5 vs Nonapeptide-1
What is the difference between Acetyl Tetrapeptide-5 and Nonapeptide-1?
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. Nonapeptide-1 is a skin & hair peptide that nonapeptide-1, sold as melanostatine 5, is a nine-amino-acid synthetic peptide built to block alpha-msh, the hormone that tells pigment cells to make melanin. it goes into brightening and dark-spot products as a gentler alternative to harsh lighteners. it is a cosmetic ingredient, not an fda-approved drug, and there is no independent peer-reviewed clinical trial of it on its own. The main differences lie in their mechanisms of action and clinical applications.
Which is better, Acetyl Tetrapeptide-5 or Nonapeptide-1?
Neither is universally "better" - the choice depends on your specific goals. Acetyl Tetrapeptide-5 is typically used for skin & hair purposes, while Nonapeptide-1 is used for skin & hair. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can Acetyl Tetrapeptide-5 and Nonapeptide-1 be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Acetyl Tetrapeptide-5 and Nonapeptide-1 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.