Every ingredient entry on this site opens by counting the literature. For myristoyl pentapeptide-17 the count is zero, and it stays zero however the search is widened.
Searched on 2026-09-11: both hyphenations of the full name, across all PubMed fields, no records. The name without its number, across all fields, no records. Of every peptide this site has catalogued, this is the only one with nothing at all filed under it — and it is on the label of a large share of the eyelash and eyebrow serums sold today.
What it actually is
PubChem CID 127264611. Reading the registered structure from the fatty end inward: a myristoyl group — fourteen carbons — attached to lysine, then leucine, alanine, lysine, and a terminal lysine amide. Formula C41H81N9O6, molecular weight 796.1.
Two features are worth naming. The peptide is strongly basic: three of its five residues are lysine, which carries a positive charge at skin pH. And it is not a glycyl-histidyl-lysine derivative. That distinguishes it from most of the peptides sold in beauty, including the ones on the neighbouring labels of the same lash serums, and it means the substantial GHK literature has nothing to say about it.
The myristoyl tail serves the same purpose as the palmitoyl tail elsewhere in the category: an unmodified peptide of this size and charge does not cross the skin barrier, and the fatty chain is the attempt to solve that. Whether it succeeds on eyelid skin specifically has not been published for this molecule.
The survey that explains the category
The most useful paper here is not about the peptide at all. Couteau and Coiffard, at the industrial pharmacy and cosmetology laboratory of Nantes Université, published a qualitative survey in Annales Pharmaceutiques Françaises in September 2026 (PMID 42269767): 79 cosmetic products promising longer, thicker or fuller eyelashes, examined for what they actually contain.
About 30% contained a prostaglandin analogue. Six distinct analogues appeared, including bimatoprost and norbimatoprost; the most common were ethyl tafluprostamide — also written as dechloro dihydroxy difluoro ethyl cloprostenolamine, or DDDE — and isopropyl cloprostenate. The authors' conclusion is blunt: such serums are on the market, promoted as lash growth treatments, and the analogues are not regulated for use in cosmetic products.
Prostaglandin analogues are the molecular family behind the licensed lash treatment, which exists because clinicians noticed glaucoma patients growing longer lashes. They are the one ingredient class in this category with an unambiguous, mechanism-backed effect on the lash cycle.
Now read how the same survey describes the rest of the shelf. The other serums, it says, are formulated with harmless ingredients such as castor oil, amino acids, panthenol, peptides and peptide derivatives.
That is a sentence about safety, not about performance. In the only recent survey of this category, the peptide serums are defined by the absence of the active that works.
The best peptide trial in the category
There is one, and it is worth setting out precisely because it is the strongest evidence a peptide lash serum has.
Fernandez-Gonzalez, Truchuelo-Díez and Gómez-Sánchez, Journal of Cosmetic Dermatology, June 2024 (PMID 38572527): thirty women aged 25 to 65, a peptide-and-glycosaminoglycan lash serum, measured at baseline, four weeks and twelve weeks with imaging software. At twelve weeks: length +8.3%, number +5%, width +10.1%, volume +14.1%, arc +13.4%, angle +28.3%. Satisfaction rose from 73.34% to 84.33%. No adverse effects.
The paper is open-label — the design word is in its own title — with no control group. Two of the three authors are in the medical affairs department of the company that sells the product. And the abstract does not name which peptides the serum contains, so it cannot be cited as evidence for myristoyl pentapeptide-17 or for any other specific ingredient.
The endpoint list also rewards attention. Lash angle rose 28.3%, the largest number in the paper, and lash angle is a measure of how lashes are lying. Twelve weeks of twice-daily application of an oil-containing serum to a lash line, with a brush, changes how lashes lie. It is the one endpoint in that set that a conditioning base alone would be expected to move, and it is the one that moved most.
The two ingredients on the same shelf, counted
Put the peptide's literature beside the literature of the class it shares the category with, searched the same day on the same database.
| Indexed records | Randomised controlled trials | |
|---|---|---|
| Bimatoprost in eyelash growth | 108 | 15 |
| Myristoyl pentapeptide-17 | 0 | 0 |
One hundred and eight records against nothing, and fifteen randomised controlled trials against none.
Set that beside the Nantes survey's finding that about 30% of lash serums contain a prostaglandin analogue, and the shape of the category becomes legible. The ingredient with all of the evidence is in roughly a third of the bottles and is usually not the one being advertised. The ingredient on the front of the label has no evidence at all. Products in the first group can be expected to do something, and are, by the survey authors' account, using an ingredient class not regulated for cosmetic use. Products in the second group are, in the same authors' word, harmless.
A shopper reading an ingredient list can tell the two apart without any specialist knowledge, because the prostaglandin analogues have distinctive names: bimatoprost, norbimatoprost, isopropyl cloprostenate, and ethyl tafluprostamide, which may also be written out as dechloro dihydroxy difluoro ethyl cloprostenolamine.
Products and labels
Myristoyl pentapeptide-17 is typically listed alongside a second peptide, a panthenol, and an oil or a conditioning polymer, well down the ingredient list. No product reviewed for this entry disclosed a concentration, and no supplier concentration for the ingredient appears in indexed literature, because no indexed literature exists.
The supporting material formulators work from is supplier documentation — technical sheets and internal studies — which is the same evidentiary layer the SNAP-8 entry describes for a different peptide. Supplier data is not worthless, but it is not published, not peer-reviewed, and not available to a shopper who wants to check it.
No Cosmetic Ingredient Review safety assessment naming this peptide could be located.
What the evidence does not show
No indexed study of this peptide, alone or in a formula that names it. No penetration data for eyelid skin, which is the thinnest on the body and the least studied. No comparison against the prostaglandin analogues that occupy a third of the same shelf. No concentration disclosed on any label reviewed.
What can be said fairly: a peptide serum with no prostaglandin analogue in it is the lower-risk purchase, which is what the Nantes survey was written to establish. The site's hair growth hub applies the same test to scalp peptides, where at least placebo-controlled trials exist to weigh.
Sources and dates
Opened 2026-09-11: PubMed E-utilities searches for myristoyl pentapeptide-17 and myristoyl pentapeptide (zero records, all fields, both hyphenations) and a structured search of the eyelash-and-peptide literature returning 18 records, all read by title, of which two were on topic; full abstracts of PMID 42269767 (Couteau and Coiffard 2026) and PMID 38572527 (Fernandez-Gonzalez et al. 2024); PubChem compound record CID 127264611 for sequence, formula and molecular weight. The comparison table was produced by two further PubMed counts run in the same session: bimatoprost with eyelash terms in a title or abstract (108 records), and the same query restricted to the randomised-controlled-trial publication type (15). No Cosmetic Ingredient Review safety assessment naming this peptide was located; the Panel's published peptide assessments cover protein-derived and plant-derived material rather than the numbered synthetic actives. Corrections go to the contact page; the review standard is on the testing notes page.