Oligopeptide-91 Sh-Polypeptide-85: 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 Oligopeptide-91 Sh-Polypeptide-85?

Oligopeptide-91 Sh-Polypeptide-85 is a lab made fusion peptide created by linking together two separate peptide genes, then letting specially selected strains of E. coli read that genetic code and assemble the final 228 amino acid chain. After fermentation the peptide is purified, checked for quality, and blended into cosmetic bases. The amino acid sequence can form natural looking folds, disulfide bridges or light sugar attachments that help it stay stable on hair strands.

Peptide technology first caught the attention of cosmetic chemists in the early 2000s when short chains of amino acids were found to support smoother stronger hair. By combining Oligopeptide-91 with Sh-Polypeptide-85 scientists aimed to pack more conditioning signals into one molecule while keeping the ingredient water friendly and easy to formulate. It has since appeared in rinse off and leave in products where a lightweight conditioning boost is wanted.

You will most often see this peptide listed on the label of masks, scalp serums, daily conditioners, nourishing shampoos, styling creams and overnight hair treatments.

Oligopeptide-91 Sh-Polypeptide-85’s Cosmetic Benefits/Uses

This peptide is added to formulas mainly to improve the feel and appearance of hair.

Hair conditioning: Oligopeptide-91 Sh-Polypeptide-85 lays a micro thin protein layer along the hair shaft that helps smooth cuticle scales, reduces static, and makes strands feel softer without heavy buildup. Over time this can lead to better manageability, less breakage during brushing and a healthier looking shine.

Who Can Use Oligopeptide-91 Sh-Polypeptide-85

This peptide is gentle enough for all hair and scalp types. Whether your scalp leans oily, dry or easily irritated it is unlikely to cause trouble because it stays mostly on the hair shaft and rinses clean. People with very sensitive skin can still benefit but may want to start with products that contain a lower percentage to make sure their scalp feels comfortable.

Because the peptide is made entirely in a lab by fermenting E. coli, no animal parts or by-products are used at any stage. That makes it a fit for vegans and vegetarians looking to avoid animal sourced proteins.

Pregnant or breastfeeding consumers can generally use conditioners or serums that include Oligopeptide-91 Sh-Polypeptide-85 since it is a large molecule that does not absorb well through intact skin. This is not medical advice so anyone who is expecting or nursing should still show the full ingredient list to their doctor before adding a new product.

The peptide does not make hair or scalp more sensitive to the sun so regular outdoor activity does not require special precautions beyond normal sun protection habits.

Potential Side Effects/Adverse Reactions

Reactions to topical Oligopeptide-91 Sh-Polypeptide-85 differ from person to person. The points below outline potential side effects yet they are uncommon when the ingredient is used correctly in a finished formula.

  • Mild scalp irritation a tingling or burning feeling that usually stops after rinsing
  • Redness or itching especially in people with pre-existing scalp conditions like eczema or psoriasis
  • Allergic contact dermatitis rare but possible for those sensitized to certain peptide structures or fermentation residues
  • Product buildup heavy use in leave-ins may weigh hair down or make it look flat

If you notice any of the above while using a product that contains this peptide stop using it and seek advice from a healthcare or skin care professional

Comedogenic Rating

Rating: 0/5 – Oligopeptide-91 Sh-Polypeptide-85 is a water-based, high molecular weight peptide that does not melt into sebum or sit inside pores, so it has virtually no clogging potential. It tends to stay on the surface of hair and rinse away with water, leaving little residue on facial skin. This makes it suitable for people who are prone to acne or breakouts.

Because it is usually blended into rinse-off or lightweight leave-in products that target the scalp and hair shaft, face contact is minimal and any residue is easily washed off during routine cleansing.

Summary

Oligopeptide-91 Sh-Polypeptide-85 is a lab crafted fusion peptide that conditions hair by laying a thin protein veil over each strand, smoothing the cuticle and cutting down on static. The result is softer, shinier hair that tangles less and breaks less during styling.

It enjoys moderate popularity, showing up most often in premium masks, serums and innovative scalp treatments rather than in every drugstore shampoo. Brands that lean into science-backed actives like to highlight it, while mainstream lines may skip it to keep costs low.

Overall safety is high: the peptide is non-comedogenic, vegan friendly and unlikely to penetrate skin deeply. Reported reactions are rare and usually mild. As with any new hair or skin product, do a small patch test first to make sure your scalp or skin agrees with the full formula.

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