Ingredient Guide

Myristoyl Pentapeptide-17

Also known as: Myristoyl Pentapeptide-17, Myristoyl Pentapeptide 17

All skin types

What It Is

A lipid-conjugated peptide (myristoyl group attached to a 5-amino-acid chain) specifically studied for its ability to support keratin gene expression in hair follicle cells — relevant to lash and brow density.

What It Does

Stimulates the expression of keratin genes in lash and brow follicle cells, theoretically supporting the production of stronger, denser hair. Used in professional-grade and mass-market lash/brow serums.

Best For

Lash density supportBrow fullness supportHair follicle peptide approach

Benefits

  • Keratin-targeting mechanism specific to hair follicles — more targeted than general hair care peptides
  • Lipid conjugation (myristoyl) improves penetration into the follicle
  • A key ingredient in multiple professional-grade lash serums

When to Be Careful

  • Results vary significantly between individuals
  • Works best with consistent twice-daily use over 6–12 weeks — results are not fast
ItGirlies Ingredient Intelligence
Why This Gets Hype

Professional lash serums at much higher price points use this peptide as a key ingredient. Its inclusion in The Ordinary's accessible lash serum brings a clinically studied compound to a wider audience.

What People Often Misunderstand

This is not a prostaglandin. Prostaglandins (found in some prescription lash products) work through a different and more potent mechanism — with more side effect risk. Myristoyl Pentapeptide-17 is gentler and safer, but results may be more modest.

Best Routine Slot

Applied to lash and brow areas morning and night, before any eye cream or moisturizer.

Good Match For

Biotinoyl Tripeptide-1, Acetyl Tetrapeptide-3, Panthenol — other lash/brow supporting ingredients

Proceed Carefully If…

Avoid getting into the eye directly. Sensitive eye areas should patch test.

Signs You May Be Overdoing It

Not a known irritant at standard concentrations.

Commonly Found In

Lash serumsBrow serumsHair density serums

Products Containing Myristoyl Pentapeptide-17

Multi-Peptide Lash and Brow Serum
The Ordinary

FAQs About Myristoyl Pentapeptide-17

Does myristoyl pentapeptide-17 grow lashes?
Evidence suggests it supports keratin production in lash follicles, which can contribute to fuller-looking lashes with consistent use. "Grow" is an oversimplification — it supports the existing follicle's ability to produce denser hair.
Why is it paired with biotinoyl tripeptide-1 in lash serums?
The two peptides target complementary pathways — myristoyl pentapeptide-17 focuses on keratin gene expression, while biotinoyl tripeptide-1 targets blood flow and follicle anchoring. Together they provide a broader lash/brow support approach.
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