Palmitoyl Tetrapeptide-20
Pal-PEKK, an alpha-MSH-agonist lipopeptide sold against grey hair. Its one paper combines cell and hair-follicle work with a small uncontrolled study in 15 men.
Palmitoyl tetrapeptide-20 is a synthetic lipopeptide, a palmitoyl group on Pro-Glu-Lys-Lys (PubChem's record, under its INCI name), designed as an agonist of alpha-melanocyte-stimulating hormone for products aimed at greying hair. In its 2018 development paper it raised catalase and lowered hydrogen peroxide in follicle cells, increased melanin production in cells and micro-dissected hairs, and was then used in a lotion by 15 men with premature greying. The paper comes from the ingredient's developers and the human study had no control group. It is not a drug.
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Recommended Dosing
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Mechanism of action
Designed as an alpha-MSH agonist: in follicle dermal papilla cells and micro-dissected human hairs it raised catalase, lowered hydrogen peroxide, raised MC1-R expression and increased melanin production (2018). No independent replication was found.
Primary uses
- Cosmetic hair-care products aimed at greying
Typical dosing
No published study states an amount of this ingredient used on skin, and a supplier's use level is not a source on this site, so none is given.
Regulatory status
Not a drug: PubChem lists it under its INCI name as a cosmetic ingredient (CID 169449956). Drugs@FDA and the EMA medicines list hold no record for it (searched October 28, 2026).
Status as of this entry's last review, October 28, 2026. Approvals, compounding rules and sport rules change; the regulatory tracker is checked more often.
What we checked
Palmitoyl tetrapeptide-20 is a hair-colour peptide with one developer paper; this section records what can be checked.
Identity, computed
| Structure | palmitoyl-Pro-Glu-Lys-Lys, free acid (read from PubChem's IUPAC name, CID 169449956) |
| Formula | C38H70N6O8 (PubChem) |
| Molecular weight | 739.0 g/mol (PubChem) |
The calculator used elsewhere on this site does not handle this N-terminal acyl group, so the formula and weight are PubChem's, not computed here.
Regulatory status, read October 29, 2026
Drugs@FDA: 0 records for “palmitoyl tetrapeptide-20”. EMA medicines list: 0 records for “palmitoyl tetrapeptide-20”. Run for semaglutide, the same queries return 6 and 5 records (and the registry search 81 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 October 28, 2026.
What the studies show
The 2018 development paper reported higher catalase activity, lower intracellular hydrogen peroxide and more melanin in cell and ex vivo hair-follicle tests, followed by a study in 15 men with premature greying who used a lotion containing it (Almeida Scalvino et al., 2018). The human part had no control group.
What we looked for and did not find
No controlled human trial, no independent study, no registry record and no drug approval.
| Source | Query | Results, October 29, 2026 | What it was |
|---|---|---|---|
| PubMed | ("tetrapeptide-20"[tiab] AND palmitoyl[tiab]) OR "Pal-PEKK"[tiab] | 1 | the hyphenated name is matched word by word; a phrase search misses it |
| ClinicalTrials.gov | palmitoyl tetrapeptide-20 | 0 | |
| Drugs@FDA (openFDA) | palmitoyl tetrapeptide-20 | 0 | |
| EMA medicines list | palmitoyl tetrapeptide-20 | 0 |
References
- [other] PubChem CID 169449956, Palmitoyl Tetrapeptide-20: formula C38H70N6O8, molecular weight 739.0. Read October 28, 2026. https://pubchem.ncbi.nlm.nih.gov/compound/169449956
- [pubmed] Almeida Scalvino S, et al. "Efficacy of an agonist of α-MSH, the palmitoyl tetrapeptide-20, in hair pigmentation." Int J Cosmet Sci, 2018;40(5):516-524. PMID: 30222197.
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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.