Tripeptide-38: 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: June 30, 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 Tripeptide-38?

Tripeptide-38 is a lab made chain of three amino acids that includes lysine and methionine. Chemists first designed it in the early 2010s while searching for small molecules that could copy some of the skin friendly signals sent by natural proteins. Using solid phase peptide synthesis, each amino acid is added step by step to build the exact sequence, then the finished peptide is purified and blended into a carrier solution. Because it is fully synthetic, it is consistent from batch to batch and free of animal or plant allergens. You will most often spot Tripeptide-38 in anti aging serums, wrinkle targeting eye creams, sheet masks, lightweight daily moisturizers and concentrated booster drops that promise smoother looking skin.

Tripeptide-38’s Cosmetic Benefits/Uses

This peptide appears on ingredient lists mainly for one job: skin conditioning. By helping the skin’s surface hold moisture and feel softer, Tripeptide-38 can leave the complexion looking plumper and more even. It supports a smoother finish that lets makeup glide on more easily and gives skin a fresher appearance over time.

Who Can Use Tripeptide-38

Tripeptide-38 suits most skin types—including normal, dry, oily, combination and sensitive—because it is lightweight water-soluble and non-fragrant. People with very reactive or allergy-prone skin may still want to monitor how their skin feels, mainly because any new ingredient has a slim chance of triggering irritation.

The peptide is produced entirely in a lab without animal by-products, making it appropriate for vegans and vegetarians.

No studies have flagged Tripeptide-38 as a concern for women who are pregnant or breastfeeding, yet safety data in these groups are limited. This is not medical advice; expectant or nursing mothers should show the product to their healthcare provider before use.

Tripeptide-38 does not increase photosensitivity, so it will not make skin more prone to sunburn. Standard daytime sun protection is still recommended.

The ingredient layers well with most other skincare actives and can be used both morning and night.

Potential Side Effects/Adverse Reactions

Responses to topical Tripeptide-38 vary from person to person. The effects listed below are possible but unlikely for most users when the ingredient is formulated correctly.

  • Mild redness or flushing
  • Temporary itching or tingling
  • Stinging sensation, especially on broken skin
  • Allergic contact dermatitis in rare cases
  • Eye irritation if the product migrates into the eyes
  • Pimples or congestion caused by other pore-clogging ingredients in the same formula

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

Comedogenic Rating

Rating: 0/5 — Tripeptide-38 is a tiny water-soluble peptide that contains no oils, waxes or fatty acids, so it does not block pores on its own. Because it rinses cleanly from the skin’s surface and leaves no residue, it is considered non-comedogenic. This makes it suitable for people who are prone to acne or regular breakouts. As always, remember that the finished product’s overall formula can change how pore friendly it is, so be sure to check what other ingredients are mixed with the peptide.

Summary

Tripeptide-38 is used in skincare to condition skin, boost surface moisture and give a smoother, plumper look. It works by mimicking signals naturally sent by proteins in healthy skin, helping the outer layer hold water and feel softer. While it delivers solid anti aging support, it has not reached the household-name status of retinol or vitamin C, yet it appears in a growing number of serums, moisturizers and eye creams aimed at fine lines and texture.

Current safety data shows Tripeptide-38 to be low risk for irritation, non-sensitizing and vegan friendly when formulated well. Still, everyone’s skin is different, so it is smart practice to do a small patch test with any new product that contains this peptide before applying it all over your face.

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