What Is Oligopeptide-91 Sh-Polypeptide-1?
Oligopeptide-91 Sh-Polypeptide-1 is a lab made peptide designed to care for hair. Scientists join the genes that code for two short protein chains—Oligopeptide-91 and Sh-Polypeptide-1—then place this new gene inside a strain of E. coli. As the bacteria grow in a controlled tank they produce the peptide, which is later separated, filtered and dried into a powder ready for cosmetic formulas. This approach lets makers create the ingredient in large amounts with steady quality and without relying on animal or plant sources.
Peptide technology reached skin care first in the early 2000s then moved into hair care when brands looked for gentler ways to strengthen strands. Oligopeptide-91 Sh-Polypeptide-1 entered the scene as part of this wave, offering a compact chain of amino acids that can stick to the hair surface and improve its feel.
You will spot the ingredient in rinse off and leave in hair products such as shampoos, conditioners, masks, serums and scalp treatments, especially those that promise smoother, stronger or fuller looking hair.
Oligopeptide-91 Sh-Polypeptide-1’s Cosmetic Benefits/Uses
This peptide is added to formulas mainly for its hair friendly action.
Hair conditioning: It forms a light film over the cuticle, helping smooth rough spots, reduce static and make hair easier to comb. By holding on to moisture it can also give strands a softer touch and a healthier shine, which is why brands often include it in products targeting dry or damaged hair.
Who Can Use Oligopeptide-91 Sh-Polypeptide-1
Because this peptide is non greasy, lightweight and nearly neutral in pH it is considered friendly for all hair and scalp types, including oily, dry, color treated and chemically processed hair. Even sensitive scalps tend to tolerate it well since it contains no fragrance or harsh solvents, though those prone to peptide allergies should stay alert for any unusual itching or redness.
The molecule is made in a lab by fermenting genetically engineered E. coli and involves no animal parts, by products or testing requirements, so it meets vegan and vegetarian standards.
There is no evidence that the ingredient penetrates deeply or reaches the bloodstream, so it is not expected to pose a risk to people who are pregnant or breastfeeding. This is not medical advice and anyone who is expecting or nursing should still check with a doctor before adding new hair products, just to be safe.
Oligopeptide-91 Sh-Polypeptide-1 does not increase photosensitivity and will not make hair or scalp more prone to sun damage. It also plays well with heat styling and common hair dyes, making it an easy add on to most routines.
Potential Side Effects/Adverse Reactions
Side effects and reactions to the topical use of Oligopeptide-91 Sh-Polypeptide-1 can vary from person to person. The following list covers potential, not guaranteed, outcomes and most users will not experience them when the ingredient is formulated and used correctly.
- Mild scalp or skin irritation
- Allergic contact dermatitis
- Eye irritation if product accidentally gets into the eyes
- Product build up that can leave hair limp if applied in very high amounts
- Reduced conditioning effect when combined with highly cationic surfactants
If you notice any of these effects stop using the product and consult a healthcare professional or dermatologist for guidance.
Comedogenic Rating
Rating: 0 (non-comedogenic)
Oligopeptide-91 Sh-Polypeptide-1 is a water-soluble peptide that leaves no oily residue and does not clog pores. It sits on the surface of hair and rinses away cleanly, so it has virtually no chance of blocking follicles or triggering breakouts. Because of this it is considered safe for people who are prone to acne or other pore-related concerns.
Since the peptide is commonly used in rinse-off or lightweight leave-in hair products the contact time with facial skin is short, which further lowers any comedogenic risk.
Summary
Oligopeptide-91 Sh-Polypeptide-1 is a lab-made peptide that conditions hair by forming a thin film that smooths the cuticle, holds moisture and reduces static. This boosts softness, shine and combability, making it valuable in products for dry or damaged strands.
While not as famous as classic skin care peptides it is slowly gaining ground in specialty shampoos, masks and serums aimed at healthier looking hair.
Safety data show a low chance of irritation, no comedogenic activity and no known long-term risks. Still, skin and scalp can react differently so it is smart to patch test any new product that contains this ingredient before full use.