Acetyl Hexapeptide-37
The Lipotec "Diffuporine" cosmetic peptide — identified by luciferase-reporter combinatorial screening as an AQP3 inducer; increases epidermal water transport and barrier proteins at cosmetic concentrations; entirely topical, no systemic development.
A synthetic acetylated hexapeptide (Ac-Ser-Pro-Ala-Gly-Gly-Pro-NH2, CAS 1447824-16-9) discovered by Lipotec (now Lubrizol) via a luciferase combinatorial peptide screen designed to identify inducers of the aquaporin-3 gene in keratinocytes. Aquaporin-3 is the dominant skin aquaporin, mediating water and glycerol flux from the basal epidermis to the stratum corneum. In-vitro data from the manufacturer show roughly two-fold upregulation of AQP3 transcription together with increases in collagen I and keratinocyte proliferation; the ingredient is marketed under the trade name Diffuporine® as a moisturising, barrier-supporting cosmetic active. No independent clinical trials; no systemic or drug development.
Mechanism of action
Induces transcriptional upregulation of the aquaporin-3 gene in epidermal keratinocytes (identified via a luciferase-reporter combinatorial screen). AQP3 is a hydroglyceroporin channel that transports water, glycerol, and urea from the basal epidermis toward the stratum corneum, contributing to both hydration and glycerol-dependent barrier lipid synthesis. Secondary manufacturer-reported effects include stimulation of keratinocyte proliferation and increased collagen I expression in dermal fibroblasts. Mechanism is cell-signalling / topical; no systemic activity is claimed.
Primary uses
- Topical cosmetic moisturising / barrier-support formulations
Typical dosing
The concentrations in circulation come from the ingredient's supplier, and a seller's figure is not a source on this site; no study in the sources read sets one.
Regulatory status
Cosmetic ingredient; not a drug. INCI-listed.
Status as of this entry's last review, October 4, 2026. Approvals, compounding rules and sport rules change; the regulatory tracker is checked more often.
What we checked
Acetyl hexapeptide-37 is a cosmetic ingredient sold as Diffuporine, said to raise aquaporin-3, a water channel in skin. PubMed holds no paper about it (the 8 hits for the phrase are word matches on other subjects, checked October 5, 2026); ClinicalTrials.gov lists two registered peptide-cream studies, with no posted results. This section records what can be checked.
Identity, computed
| Sequence | Ac-Ser-Pro-Ala-Gly-Gly-Pro-NH2 (Ac-SPAGGP-NH2) |
| Formula | C22H35N7O8 |
| Average mass | 525.56 g/mol |
| Monoisotopic mass | 525.2547 Da |
| Isoelectric point | 0.0 (net charge +0.0 at pH 7) |
The dataset gives Ac-Ser-Pro-Ala-Gly-Gly-Pro-NH2, and the calculator agrees with its formula and mass.
Regulatory status, read October 5, 2026
Drugs@FDA: 0 records for “acetyl hexapeptide-37”. EMA medicines list: 0 records for “acetyl hexapeptide-37”. Run for semaglutide, the same queries return 6 and 5 records (and the registry search 84 trials), so a zero here is an absence, not a broken search. Not named on the WADA 2026 and 2027 Prohibited Lists. As a substance with no current approval for human therapeutic use, it falls under section S0 (non-approved substances), which is prohibited at all times; the lists were read on September 27, 2026.
What the maker or sellers claim
Claim, from the ingredient's maker and cosmetic sellers: It boosts skin hydration and barrier function by increasing aquaporin-3. Those data come from the maker's own technical material, not peer-reviewed studies.
About aquaporin-3
Aquaporin-3 moves water and glycerol through the skin's outer layers; mice lacking it have dry skin and impaired barrier repair, as the review cited in References describes. That is evidence about the channel, not about this peptide.
What we looked for and did not find
No published study, no posted trial result and no drug application.
| Source | Query | Results, October 5, 2026 | What it was |
|---|---|---|---|
| PubMed | "acetyl hexapeptide 37" | 8 | word matches only; none is about this peptide (titles checked) |
| PubMed | Diffuporine | 0 | |
| ClinicalTrials.gov | acetyl hexapeptide-37 | 2 | two registered peptide-cream skin studies (NCT07614698, NCT07548424); no results posted |
| Drugs@FDA (openFDA) | acetyl hexapeptide-37 | 0 | |
| EMA medicines list | acetyl hexapeptide-37 | 0 |
References
- [manufacturer] Lipotec / Lubrizol. "Diffuporine™ (Acetyl Hexapeptide-37) technical data sheet." CAS 1447824-16-9.
- [review] Oshimura E, Sakamoto K. "Amino acids, peptides, and proteins." In: Cosmetic Science and Technology: Theoretical Principles and Applications, 2017; pp. 285-303.
- [review] Hara-Chikuma M, Verkman AS. "Roles of aquaporin-3 in the epidermis." J Invest Dermatol, 2008;128(9):2145-2151 (AQP3 function in skin). PMID: 18548108.
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This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.