R-Tetrapeptide-38 Hexapeptide-40 Oligopeptide-152 Sh-Polypeptide-106: 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 R-Tetrapeptide-38 Hexapeptide-40 Oligopeptide-152 Sh-Polypeptide-106?

R-Tetrapeptide-38 Hexapeptide-40 Oligopeptide-152 Sh-Polypeptide-106 is a lab designed fusion peptide made by stitching together the genetic codes for four smaller peptides. Scientists build this combined gene, place it inside a friendly strain of E. coli, then let the bacteria ferment in controlled tanks. The bacteria act like mini factories, churning out a long single chain that holds 493 amino acids. After harvest the peptide is purified, checked for quality and blended into cosmetic bases. The finished ingredient may form disulfide links and pick up small sugar groups that help keep its shape.

Interest in multi peptide blends grew in the early 2000s when brands began looking for gentler ways to boost hair and skin health. By fusing several known peptide segments into one chain, formulators hoped to pack more activity into a lower dose. Today this ingredient appears in leave-in conditioners, scalp tonics, hair masks and strengthening serums where it is prized for its conditioning touch.

R-Tetrapeptide-38 Hexapeptide-40 Oligopeptide-152 Sh-Polypeptide-106’s Cosmetic Benefits/Uses

This peptide’s main job in cosmetics is hair conditioning. It forms a light film along the hair shaft that helps smooth the cuticle, reduce snagging and boost softness. Regular use can make strands feel stronger and look shinier which in turn makes styling easier and helps limit breakage during brushing.

Who Can Use R-Tetrapeptide-38 Hexapeptide-40 Oligopeptide-152 Sh-Polypeptide-106

This peptide suits all hair and scalp types including dry, oily, balanced and textured strands because it sits on the cuticle rather than altering sebum flow or pH. Those with sensitive skin generally tolerate it well thanks to its large molecular size which limits deep penetration. If you have a history of protein sensitivity or severe atopic dermatitis around the scalp you may want to proceed with extra caution as any new protein could in theory trigger irritation.

The ingredient is produced by fermenting a lab built gene in E. coli, not extracted from animals, so both vegans and vegetarians can feel comfortable using it.

No specific warnings exist for use during pregnancy or breastfeeding. Current data shows low likelihood of systemic absorption, still this is not medical advice and anyone who is pregnant or nursing should run any cosmetic product past a qualified healthcare provider to be safe.

R-Tetrapeptide-38 Hexapeptide-40 Oligopeptide-152 Sh-Polypeptide-106 does not make skin or hair more sensitive to sunlight, so added sun protection is not required beyond normal daily habits. It is also free of common sensitizers like fragrance allergens and dyes unless the finished formula introduces them.

Potential Side Effects/Adverse Reactions

Responses to topical use of R-Tetrapeptide-38 Hexapeptide-40 Oligopeptide-152 Sh-Polypeptide-106 vary from person to person. The points below outline potential effects that are possible yet unlikely for most users when the ingredient is properly formulated and used as directed.

Scalp or skin irritation

Redness or itching in individuals with pre existing protein allergies

Temporary stinging on abraded or freshly shaved areas

Product buildup leading to limp or weighed down hair if used excessively without clarifying washes

Very rare contact dermatitis in those with highly reactive skin conditions

If you notice any discomfort or unexpected reaction stop using the product and consult a healthcare professional or dermatologist for guidance.

Comedogenic Rating

Rating: 0 / 5. R-Tetrapeptide-38 Hexapeptide-40 Oligopeptide-152 Sh-Polypeptide-106 is a very large water-soluble molecule that stays on the surface of hair shafts and rinses easily from the skin. It cannot sink into pores or mix with skin oils in a way that would block follicles. This makes it suitable for people who are prone to acne or breakouts. As always the finished product’s overall formula can influence pore clogging potential so lightweight vehicles are preferable for facial use.

Summary

R-Tetrapeptide-38 Hexapeptide-40 Oligopeptide-152 Sh-Polypeptide-106 is a lab crafted fusion peptide used mainly to condition hair. By forming a thin flexible film along each strand it smooths cuticles improves slip boosts shine and helps reduce breakage during brushing. Although effective it remains a niche ingredient found mostly in premium leave-ins scalp serums and strengthening masks rather than mass market lines.

Current evidence shows a low risk of irritation or systemic absorption so it is generally considered safe for everyday cosmetic use. Still everyone’s skin is different so it is wise to patch test any new product that contains this peptide before full application.

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