Myristoyl Tetrapeptide-20: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: July 1, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Myristoyl Tetrapeptide-20?

Myristoyl Tetrapeptide-20 is a lab-crafted molecule formed when myristic acid, a fatty acid that can be sourced from coconut or palm kernels, is linked to a short chain of four amino acids known as Tetrapeptide-20. Joining the fatty acid to the peptide helps the ingredient blend smoothly with the skin’s natural oils, allowing it to sink in more easily. Peptide technology started gaining ground in skin care in the late 1990s, and this particular peptide-fatty acid combo was introduced as brands searched for gentle yet effective options that support the skin’s appearance without harsh actives.

To create Myristoyl Tetrapeptide-20, chemists first synthesize the tetrapeptide in a controlled environment, often using plant-derived amino acids. They then attach myristic acid to one end of the peptide through a process called acylation. The finished ingredient is purified, dried and blended into cosmetic bases.

You will usually spot Myristoyl Tetrapeptide-20 in leave-on products where its skin-loving traits have time to work. These include lightweight serums, daily moisturizers, eye creams, overnight masks, firming lotions and targeted anti-aging treatments.

Myristoyl Tetrapeptide-20’s Cosmetic Benefits/Uses

Brands choose Myristoyl Tetrapeptide-20 mainly for its skin conditioning talent, which helps formulas feel elegant while keeping the complexion looking and feeling its best.

As a skin conditioning agent, Myristoyl Tetrapeptide-20 supports the skin’s natural barrier so moisture stays in and dryness stays out. Regular use can leave skin feeling softer, smoother and more supple, creating a healthier-looking surface that better reflects light and looks refreshed.

Who Can Use Myristoyl Tetrapeptide-20

Myristoyl Tetrapeptide-20 is generally well tolerated by all skin types, including dry, normal, combination, oily and even sensitive skin thanks to its gentle, barrier-supporting nature. Those with very oily or acne-prone skin may still appreciate its lightweight feel since the peptide is not an oil and adds no greasy film.

The ingredient can be formulated with plant-derived myristic acid and lab-synthesized amino acids, making it suitable for vegans and vegetarians when sourced this way. If that matters to you be sure to check with the brand about its raw material suppliers.

Current data shows no specific concerns for women who are pregnant or breastfeeding when the ingredient is used topically in cosmetic amounts. This is not medical advice, so anyone expecting or nursing should review new products with a qualified healthcare professional just to be safe.

Myristoyl Tetrapeptide-20 does not increase photosensitivity, so it will not make skin more prone to sunburn. Standard daily sunscreen use is still recommended for overall skin health.

Potential Side Effects/Adverse Reactions

Side effects and reactions to the topical application of Myristoyl Tetrapeptide-20 can vary from person to person. The points below outline potential issues only, and most users will not experience them when the ingredient is properly formulated within a product.

  • Temporary redness or warmth
  • Mild itching or tingling
  • Localized rash or hives in those with peptide sensitivities
  • Breakouts if combined with highly comedogenic oils in the same formula
  • Allergic contact dermatitis in rare cases

If any negative reaction occurs stop using the product and consult a healthcare professional.

Comedogenic Rating

Rating: 1/5

Myristoyl Tetrapeptide-20 is used at very low levels and carries a peptide backbone that dilutes the pore-clogging potential of the attached myristic acid. It is lightweight, does not leave an oily film and is typically blended into non-greasy bases, so the likelihood of it blocking pores is minimal. Suitable for acne-prone skin in most cases.

If a product containing this peptide also packs rich butters or highly comedogenic oils, the overall formula could still trigger breakouts, so always look at the full ingredient list.

Summary

Myristoyl Tetrapeptide-20 is a skin-conditioning peptide that helps reinforce the moisture barrier, leaving skin softer, smoother and more supple. It achieves this by combining a fatty acid that melds with skin lipids and a short amino acid chain that signals a healthier surface.

The ingredient sits in the “up-and-coming” category: not as famous as retinol or vitamin C yet valued by formulators who want gentle performance boosters.

Current research and industry usage point to a strong safety profile with low irritation risk. Still, everyone’s skin is unique so it is wise to patch test any new product featuring Myristoyl Tetrapeptide-20 before fully committing.

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