What Is Myristoyl Pentapeptide-17 in Lash Serum?

Plain answer: Myristoyl Pentapeptide-17 is a small lab-made peptide in some lash serums. Brands say it may help lashes look fuller. Human studies have tested blends that include it. Those blends had many other ingredients too. The studies cannot show what this one peptide did. Direct human proof for lash growth is still limited.

Review status: This is a source-checked editorial draft. Qualified review required before indexation. An ophthalmologist or optometrist must review ocular and drug claims. A dermatologist or cosmetic toxicology expert must review claims within their scope.

Quick facts

Exact INCI name	Myristoyl Pentapeptide-17
Ingredient type	Cosmetic peptide.
What labels claim	Conditioning or support for fuller-looking lashes. Claims vary by brand and formula.
Ingredient-specific evidence grade	E because the reviewed human eyelash studies did not isolate this peptide.
Finished-formula evidence	C for small, uncontrolled human studies of multi-ingredient formulas.
Source check	2026-07-11

Does Myristoyl Pentapeptide-17 grow eyelashes?

The direct answer is not proven. Our search found human studies of finished lash formulas that included Myristoyl Pentapeptide-17. Those formulas also included other peptides, growth factors, vitamins, extracts, or conditioning ingredients. The studies cannot tell us which ingredient caused a change.

A 2020 open-label study followed 30 participants, with 29 completing 90 days, using a polygrowth-factor serum. That formula included Myristoyl Pentapeptide-17 and Myristoyl Hexapeptide-16 alongside several growth factors and other ingredients. SkinGen International funded the work through an educational grant. Improvements belong to the finished formula, not to one peptide.

A 2024 eye-area cosmetic study evaluated another finished lash and brow formula that listed Myristoyl Pentapeptide-17. It can inform tolerability of that exact formula under its study conditions. It does not establish isolated peptide efficacy or universal eye-area safety.

Effectiveness evidence

The Lash List editorial grade key: A = strong controlled human evidence for the exact use. B = one controlled human study. C = a small uncontrolled human formula study. D = laboratory, animal, scalp-hair, or supplier evidence. E = label presence, theory, or no direct human eyelash evidence. This is our editorial rubric, not a recognized clinical grading system. Grades do not rate safety.

Evidence	Evidence grade	What it means
Direct independent controlled human eyelash trial of isolated Myristoyl Pentapeptide-17	E	No relevant study was found in this source review. Avoid a direct growth claim.
Open-label human study of a multi-ingredient formula containing it	C	The formula showed changes over time, but there was no isolated ingredient effect and no blinded vehicle control.
Supplier keratin or laboratory claims	D	Mechanistic or supplier evidence cannot be presented as clinical eyelash growth.
Presence on an official product label	E	Shows presence only, not concentration, efficacy, or safety.

Safety assessment

Assessment status	Assessed under stated conditions in a 2025 Danish EPA project. The report found no health concern for three selected peptides at the low concentrations and use amounts studied. This is not a universal formula clearance.
Authority	Danish EPA-commissioned survey and risk assessment; peer-reviewed finished-formula studies. European Commission CosIng is naming context, not a safety approval.
Scope	Myristoyl Pentapeptide-17 was one of three peptides measured across 19 serums bought in Denmark and the EU. The highest measured level of any of the three was about 0.006%.
Jurisdiction	Danish and EU market survey context. No global regulatory approval or formula-wide conclusion is claimed.
Known effects	The Danish report found no direct toxicology data for the peptide. It assessed the building blocks, could not identify a critical effect or a point of departure for quantitative risk assessment, and concluded no health concern for the three peptides under surveyed use. In the 2020 formula study, two of 30 participants had mild stinging for two to five seconds.
Data gaps	No direct toxicology data were found for the peptide itself. Relevant eye irritation and skin sensitization tests were limited, and other concentrations, full formulas, long-term exposure, and pregnancy were outside the conclusion.
Checked date	2026-07-11

What did the Danish EPA report assess?

The 2025 project surveyed 44 prostaglandin-free lash or brow serums, then measured Myristoyl Pentapeptide-17, Biotinoyl Tripeptide-1, and Acetyl Tetrapeptide-3 in 19 products. It found low measured levels and no health concern for those three peptides under the project's exposure assumptions.

The same report found no direct toxicology data for Myristoyl Pentapeptide-17 itself. It assessed the peptide's building blocks and named missing local eye and skin tests. That makes the report useful safety evidence, but not proof that every peptide serum is safe.

Why a supplier keratin percentage is not enough

A supplier or laboratory result can help explain why a brand selected an ingredient. It cannot show that a person will grow longer eyelashes. Laboratory keratin production is a different endpoint from measured human lash length, number, width, or volume.

Until the underlying test method, concentration, sponsor, comparator, and full report are available, a percentage should be labeled as supplier evidence. It should not be called a clinical eyelash result.

Which current labels list it?

These official labels were checked on 2026-07-11. Formula presence does not prove effect, concentration, or tolerability.

Product	Official formula source	Boundary
The Ordinary Multi-Peptide Lash and Brow Serum	The Ordinary label	The brand says formulas can vary by time and region. Check the box.
GrandeLASH-Sensitive	Grande Cosmetics label	A long multi-ingredient formula. Presence cannot isolate this peptide.

What does CosIng tell us?

The European Commission says CosIng contains cosmetic ingredient names and reported functions. It also warns that an inventory listing is not a positive list, approval, or legal authorization. Use CosIng to check naming context, not to prove that an ingredient grows lashes or is safe at every dose.

How should you read this name on a label?

Keep the exact INCI spelling and number.
Do not assume every ingredient ending in peptide has the same function or evidence.
Do not estimate concentration from label position alone.
Judge formula studies as formula studies, not single-ingredient trials.
Use the Ingredient Checker for identification, then read the evidence source.

Sources and evidence limits

Current product label examples

The current official U.S. ingredient lists for SOWN Root 1 and The Ordinary Multi-Peptide Lash and Brow Serum name Myristoyl Pentapeptide-17. A label match proves presence only. It does not show the amount or prove that this one peptide caused a finished-formula result. Sources checked July 11, 2026; formulas can change.

Related ingredient pages

Use the evidence system

Return to the lash serum ingredient hub, paste a current ingredient label into the checker, or read the ingredient risk guide.

This page is educational. It does not diagnose an eye condition or replace advice from a qualified clinician.