Myristoyl Pentapeptide 17

What Is Myristoyl Pentapeptide-17 in Skincare?

Myristoyl Pentapeptide-17 is a short chain of five amino acids (lysine, leucine, alanine, lysine, lysine) bonded to myristic acid, a fatty acid that helps it sit well on skin and hair. It is the best-known peptide in cosmetic lash and brow serums, where it is used for the look of longer, fuller, thicker lashes and brows. It is often blended with Myristoyl Hexapeptide-16 and Biotinoyl Tripeptide-1.

EWG Skin Deep rating for Myristoyl Pentapeptide 17

Myristoyl Pentapeptide-17 Quick Facts

How Myristoyl Pentapeptide-17 Works

Lashes and brows are made mostly of keratin, the same structural protein found in scalp hair. Supplier data describe lash peptides like Myristoyl Pentapeptide-17 as supporting keratin production in the hair follicle and supporting the adhesion proteins that hold each lash in place. The goal is the look of lashes and brows that are thicker, longer, and better anchored.

What the evidence shows, and what it does not

• Supplier data: Symrise, which developed SymPeptide 226EL with Therapeutic Peptides Inc., reported that lash length and fullness looked up to 48% better in two weeks at the recommended use level. The number of volunteers and the concentration were not published, so read this as a marketing figure.
• Independent study: A 2024 open-label study in the Journal of Cosmetic Dermatology followed 30 women aged 25 to 65 who used a lash serum built on peptides and glycosaminoglycans for 12 weeks. Compared with baseline, measured lash length rose 8.3%, number 5%, width 10.1%, and volume 14.1%, and no adverse effects were reported. The abstract does not name the peptides, and there was no placebo group.

The honest summary: lash peptides have encouraging, mostly supplier-backed data, and the 2024 study reported no adverse effects. Expect a gradual change in how lashes look over two to three months, not a dramatic overnight result.

Peptides vs prescription lash products

Peptide lash serums are cosmetics. They do not contain the prostaglandin-type ingredients used in prescription lash products, which is why they are sold over the counter and used for appearance only.

How to Use It: Formulating Notes

• Rate: Use 10% of the multi-peptide complex, the top of the 1-10% supplier range. At the Skin Perfection house rate of 9 drops = 1% per fluid ounce, that is 90 drops per 1 oz, or 22 drops per 0.25 oz lash vial. If you combine it with Myristoyl Hexapeptide-16, use 5% of each.
• Add it last: Add the peptide as the final step, below 30°C (86°F).
• Skip xanthan gum: The supplier data sheet lists the lash complex as not compatible with xanthan gum. Use a different gel former or a ready-made lash base.
• Avoid these: Strong acids, strong bases, metal ions, active enzymes, and fragrance compounds with aldehyde or ketone groups.
• pH: Keep the finished serum between pH 5.0 and 7.0.
• Storage: The supplier rates the complex for 12 months at room temperature or 24 months refrigerated at 2-8°C, tightly closed and away from light. Refrigerate your finished serum between uses.

Simple Lash and Brow Serum (0.25 oz vial)

1. Fill a clean 0.25 oz lash vial with the Lash and Brow Bulk Base, leaving room at the top.
2. Add 22 drops of the Eyelash Peptide for Lashes and Brows for 10%.
3. Cap and shake well.
4. Brush a thin line along the base of the upper lashes, like eyeliner, and over the brows, morning and night. Keep it out of the eye itself.

Who It Suits

Myristoyl pentapeptide-17 suits anyone whose lashes or brows look shorter, thinner, or sparser than they would like, including after years of lash curlers, extensions, or over-plucking. It is popular as a gentle, cosmetic first step before trying anything stronger.

Sensitive skin and eyes: Patch test the finished serum on the inner arm for 24 hours, then try it on a small area of the brow before using it at the lash line. Start at the lowest rate of the range (for example 5%) and work up. Stop if your eyes or lids feel irritated, and see a doctor if lash or brow loss is sudden or patchy, because that is not a cosmetic concern.

Frequently Asked Questions

What does myristoyl pentapeptide-17 do?

It helps lashes and brows look longer, thicker, and fuller. Supplier data describe it as supporting keratin, the main protein in lashes and brows.

Does myristoyl pentapeptide-17 really work?

The evidence is encouraging but limited. Supplier studies report visible changes within weeks, and a 2024 open-label study of a peptide lash serum measured 8.3% longer and 14.1% more voluminous-looking lashes after 12 weeks, without a placebo group.

How long does it take to see results?

Give it 8 to 12 weeks of twice-daily use. Lashes renew slowly, and the 2024 study measured its results at 12 weeks.

Is myristoyl pentapeptide-17 safe to use near the eyes?

It is widely used in cosmetic lash serums, and the 2024 study reported no adverse effects. Apply only along the lash line, keep it out of the eye, and stop if you notice irritation.

What is the difference between myristoyl pentapeptide-17 and myristoyl hexapeptide-16?

They are closely related lash peptides of five and six amino acids. They are often used together, at 5% each, so a formula covers both.

How much should I add to a lash serum?

Use 10% of the lash peptide complex, which is 90 drops per fluid ounce or 22 drops in a 0.25 oz vial. Use 5% of each if you combine two peptides.

Can I use it on my eyebrows?

Yes. Brush it over the brows morning and night for the look of fuller, more defined brows.

Shop Lash and Brow Peptides

Make your own serum with the Eyelash Peptide for Lashes and Brows and the Lash and Brow Bulk Base. For more tips, read how to make lashes look thicker or visit our lash and brow collection.

Sources

• Open clinical trial evaluating the efficacy of a novel eyelash enhancer with peptides and glycosaminoglycans (title abridged). Journal of Cosmetic Dermatology. 2024. doi:10.1111/jocd.16265 (open-label human study, n = 30, 12 weeks)
• Symrise, SymPeptide 226EL supplier announcement, reported in Personal Care Magazine: "up to 48%" lash length and fullness in two weeks (supplier data, n not published)
• SpecPed Lash1617 technical data sheet, 2023: INCI, 1-10% dosage, pH 5.0-7.0, below 30°C, xanthan gum incompatibility, storage (supplier data)
• Skin Perfection, Eyelash Peptide for Lashes and Brows product page: 10% rate, 5% each when combined, 9 drops = 1% per fl oz

These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.

About the Author
Written by Kari Thomas, cosmetic formulator and founder of Skin Perfection.