Pentapeptide-39: 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
Share:
Inside this article:

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 Pentapeptide-39?

Pentapeptide-39 is a lab made chain of five amino acids built mainly from glutamine, glycine and proline. It belongs to the growing family of cosmetic peptides that aim to support healthy looking skin. Researchers first turned to short peptides for beauty products in the early 2000s when new equipment made it easier to copy small fragments of natural proteins. The peptide is produced through a precise method called solid phase peptide synthesis, where each amino acid is added step by step until the final five unit chain is complete, then it is purified and dried into a stable powder.

You will most often spot Pentapeptide-39 in firming serums, anti aging creams, sheet masks, eye gels and body contouring lotions. Brands add it when they want a gentle yet targeted ingredient that can give skin a smoother feel without heavy oils or fragrances.

Pentapeptide-39’s Cosmetic Benefits/Uses

Its main job in skincare is simple and focused.

As a skin conditioning agent, Pentapeptide-39 helps the outer layer of skin hold on to moisture so it feels softer and looks more even. This conditioning action can also make other hydrating ingredients work better because the surface stays comfortable and prepared to absorb lightweight creams or serums.

Who Can Use Pentapeptide-39

Pentapeptide-39 is considered gentle enough for most skin types, including oily, dry sensitive and combination skin, because it is lightweight and free of pore-clogging oils. People with very reactive or allergy-prone skin should still check the full product list to be sure no other ingredients cause trouble for them, but the peptide itself rarely poses an issue.

The peptide is produced entirely by chemical synthesis and contains no animal-derived material, so it is suitable for both vegans and vegetarians. Most manufacturers also market it as cruelty free since animal testing is not required for the raw material.

Pregnant or breastfeeding individuals can generally use products with Pentapeptide-39 since it sits on the surface of skin and is not known to enter the bloodstream in meaningful amounts. This is not medical advice and anyone who is expecting or nursing should have a quick word with a healthcare professional before adding new skincare, just to be safe.

Pentapeptide-39 does not make skin more sensitive to sunlight, so there is no special need for additional sun-care steps beyond the daily SPF dermatologists already recommend.

Potential Side Effects/Adverse Reactions

Reactions to topical Pentapeptide-39 differ from person to person. The following list covers potential side effects but most users will not notice any problems when the ingredient is used at the levels normally found in cosmetics.

  • Mild redness or warmth shortly after application
  • Temporary tingling or stinging in very sensitive skin
  • Itching or small bumps if an individual is allergic to a preservative or fragrance in the same formula
  • Rare cases of contact dermatitis in people with a specific peptide sensitivity

If you experience any of these effects stop using the product and consult a healthcare professional for guidance.

Comedogenic Rating

Rating: 0 out of 5. Pentapeptide-39 is a small water-soluble molecule that does not leave an oily film or block pores, so it is considered non-comedogenic. This makes it a friendly choice for people who struggle with clogged pores or blackheads. Because the peptide itself is non-greasy it is generally suitable for acne-prone skin, though the overall formula still matters. If the product also contains heavy oils, waxes or thick silicones those ingredients, not the peptide, could raise the comedogenic risk.

Summary

Pentapeptide-39 is a lab made chain of five amino acids used mainly as a skin conditioning agent. It helps the outer layer of skin hold moisture, leaving it softer, smoother and better prepared to receive other hydrating ingredients. By supporting a healthy surface it can subtly improve the look of firmness without relying on heavy emollients.

The ingredient is gaining visibility in firming serums and masks, yet it is still less common than well-known peptides like Matrixyl or copper peptides. Its gentle profile, vegan origin and low chance of irritation make it easy for brands to incorporate when they want a lightweight, modern peptide.

Safety data shows Pentapeptide-39 is well tolerated at the low concentrations used in cosmetics, with only rare reports of sensitivity. As with any new skincare ingredient it is wise to do a quick patch test when trying a fresh formula to confirm personal compatibility.

Was this article helpful?
More from Glooshi:
ADVERTISEMENT
Get all our top headlines in beauty.
Delivered right to your inbox each week. Zero spam, all goodness, opt-out at anytime.
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Get the latest beauty news, top product recommendations & brand-exclusive discount codes direct to your inbox.
Send good feedback:

All feedback is greatly appreciated, anonymous, and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Send bad feedback:

All feedback is greatly appreciated, anonymous, and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Search