What Is Oligopeptide-91 Sh-Polypeptide-9?
Oligopeptide-91 Sh-Polypeptide-9 is a lab designed fusion peptide built from 186 amino acids, created by combining the genetic sequences of two shorter peptides. Manufacturers insert the custom gene into harmless E. coli, let the bacteria ferment in controlled tanks, then harvest and purify the peptide. During this process the chain may form disulfide links or pick up sugar groups, both of which help stabilize its structure. Peptides began turning up in beauty formulas in the early 2000s when brands noticed their ability to mimic natural proteins and support hair and skin health. As research advanced, tailored peptides like Oligopeptide-91 Sh-Polypeptide-9 were developed to deliver targeted performance with a lighter feel than traditional oils or silicones. Today this ingredient is most often blended into rinse-out and leave-in conditioners, hair masks, scalp serums, anti-aging hair treatments and multitasking styling creams where it can condition without weighing strands down.
Oligopeptide-91 Sh-Polypeptide-9’s Cosmetic Benefits/Uses
This peptide’s main value in beauty products is its ability to care for hair.
As a hair conditioning agent, Oligopeptide-91 Sh-Polypeptide-9 helps smooth the cuticle, reduce frizz, and improve softness. Its protein-like structure can temporarily fill in weak spots along the strand, giving hair a stronger, silkier feel and adding a healthy looking shine. Unlike heavier conditioners, it does this without leaving a greasy film so styles stay light and bouncy.
Who Can Use Oligopeptide-91 Sh-Polypeptide-9
This peptide is generally considered suitable for all skin and scalp types, including dry, oily, combination and sensitive. It is lightweight, water soluble and free of pore-clogging oils so it does not normally aggravate breakouts or leave a greasy residue. People with very protein-sensitive hair might notice a stiff feel if they use multiple protein treatments at once, so they may want to limit usage to a few times a week.
Because the peptide is made through bacterial fermentation without animal-derived ingredients or byproducts, products featuring it are typically appropriate for vegans and vegetarians. Formulators should still confirm that the entire finished formula and packaging align with vegan or cruelty-free standards.
No studies have flagged Oligopeptide-91 Sh-Polypeptide-9 as unsafe for pregnant or breastfeeding women when used topically, and absorption through intact skin is expected to be minimal. That said, research in these groups is limited. This information is not medical advice and anyone who is pregnant or nursing should show any cosmetic product they plan to use to a qualified healthcare provider to be sure it fits their personal situation.
The ingredient is not known to cause photosensitivity, so it does not make skin or scalp more prone to sunburn. Normal sun protection measures should still be followed when spending time outdoors.
Potential Side Effects/Adverse Reactions
Responses to topical Oligopeptide-91 Sh-Polypeptide-9 vary between individuals. The following list covers potential issues only. When the ingredient is correctly formulated most users will not experience any of these reactions.
- Mild scalp or skin irritation such as redness or itching
- Allergic contact dermatitis in those sensitized to peptides or preservative systems used alongside the ingredient
- Transient stinging if applied to broken or freshly exfoliated skin
- Dryness or stiffness in hair for those who are protein sensitive or combine several protein-rich products
- Rare contamination-related reactions if manufacturing hygiene is poor
- Loss of effectiveness or unexpected texture changes when layered with highly acidic or alkaline treatments that can denature peptides
If any uncomfortable reaction develops stop using the product immediately and seek advice from a pharmacist or healthcare professional.
Comedogenic Rating
Rating: 0/5 (non-comedogenic)
Oligopeptide-91 Sh-Polypeptide-9 is a large water-soluble peptide that contains no oils, waxes or fatty acids, so it cannot clog pores or trap sebum. Its molecular size also makes it unlikely to penetrate deeply enough to block follicles. For these reasons it earns the lowest possible comedogenic score.
Suitable for acne-prone or breakout-prone skin and scalp.
Because it is typically added at low concentrations and is fully rinsable in many hair products, the risk of pore congestion remains minimal even when used daily.
Summary
Oligopeptide-91 Sh-Polypeptide-9 is a lab-crafted fusion peptide used mainly as a hair conditioner. By mimicking the structure of natural keratin fragments it can temporarily patch weak spots along the cuticle, smooth frizz and boost softness, shine and manageability without adding weight or grease.
The ingredient is still niche compared with well-known oils or silicones yet it is gaining traction among premium haircare brands that want lightweight performance and a vegan profile.
Safety data so far shows a low risk of irritation or sensitivity, no comedogenicity and negligible systemic absorption. Even so, skin and scalp vary from person to person so it is wise to patch test any new product that features this peptide before full use.