Peptides

Tripeptide-38

INCI: TRIPEPTIDE-38

Reviewed by Emma · Last updated 2 Jun 2026

A peptide that may support skin firmness and reduce the appearance of fine lines

Best For Skin Types

All, Mature

Addresses

Fine lines, Firmness, Texture, Elasticity

Usage Frequency

Daily

What Is Tripeptide-38?

Tripeptide-38, also known as palmitoyl tripeptide-38, is a synthetic peptide composed of three amino acids bonded together and attached to a fatty acid chain. Peptides are short chains of amino acids that can penetrate the outer layers of skin and communicate with deeper skin cells. This particular tripeptide is designed to signal fibroblasts—the cells responsible for producing collagen and elastin—to increase their activity.

In skincare formulations, tripeptide-38 functions as a skin conditioning agent. It appears in serums and moisturisers typically at low concentrations, often in combination with other active ingredients such as vitamins C and E or plant extracts.

How It Works

Tripeptide-38 is thought to work by mimicking natural signalling molecules that stimulate fibroblasts to produce and maintain collagen and elastin. These proteins are essential for skin structure, firmness and elasticity. By encouraging this natural production pathway, the peptide may help support the skin's own repair and renewal processes.

The fatty acid chain attached to the peptide may also help it penetrate the stratum corneum (the outermost skin barrier) and remain in the skin longer, allowing for more sustained communication with deeper skin cells.

Clinical Evidence & References

Available research suggests tripeptide-38 may have a measurable effect on visible signs of ageing when used in multi-ingredient formulations. In clinical studies, serums and moisturisers containing this peptide alongside other actives—such as vitamin C, vitamin E, plant extracts and coenzyme Q10—showed improvements in fine lines, skin roughness and overall appearance after 4-8 weeks of daily use in women aged 35 and above.

However, most published research involves complex formulations rather than tripeptide-38 in isolation, making it difficult to determine the ingredient's individual contribution. Evidence is strongest for use as part of a comprehensive anti-ageing routine rather than as a standalone solution. Further research specifically isolating this peptide's effects would help clarify its efficacy.

How to Use

Tripeptide-38 is typically used in serums or moisturisers applied once or twice daily to clean skin. For best results, apply to damp skin before heavier creams to optimise absorption. Results are generally subtle and cumulative; consistent use over 4-8 weeks is usually necessary to notice visible improvements in fine lines or texture. It pairs well with complementary ingredients like vitamin C or niacinamide.

Safety & Precautions

Tripeptide-38 is generally well-tolerated and considered safe for topical use. Allergic reactions are rare, though those with sensitivity to peptides should perform a patch test first.

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