What Is Rh-Polypeptide-105?
Rh-Polypeptide-105 is a lab produced version of a naturally occurring signaling protein known as CXCL1 or neutrophil-activating protein 3. Scientists first studied it in the late 1980s for its role in cell growth. Over time they found that a carefully modified form could help support healthy hair fibers when applied to the scalp or strands. Because the original protein is sourced from human biology, makers now rely on recombinant technology, meaning they insert the genetic code for the protein into safe host cells like yeast or bacteria. The cells act like tiny factories, producing large amounts of the polypeptide which is then purified, filtered and blended into cosmetic grade liquid. You will mainly see Rh-Polypeptide-105 in leave-on scalp serums, targeted hair masks, strengthening conditioners and premium anti-breakage treatments.
Rh-Polypeptide-105’s Cosmetic Benefits/Uses
In formulas Rh-Polypeptide-105 serves as a hair conditioning agent. By coating the hair shaft it helps improve softness, manageability and shine. It can also support the look of thicker fuller strands by helping the cuticle lie flat which allows light to reflect more evenly. Regular use in a leave-on product may reduce the appearance of dryness and breakage making hair feel smoother and healthier overall.
Who Can Use Rh-Polypeptide-105
Rh-Polypeptide-105 is gentle enough for most scalp and hair types including dry, oily, normal and color treated strands. Its lightweight conditioning action makes it suitable even for fine hair since it rinses clean without leaving a heavy film. Sensitive scalps generally tolerate it well, though anyone with a known protein sensitivity should proceed cautiously.
The ingredient is produced through recombinant fermentation in yeast or bacteria, so it contains no animal derived material. That makes products formulated with Rh-Polypeptide-105 appropriate for both vegans and vegetarians as long as the rest of the formula is also animal free.
Current data shows no specific risks for pregnant or breastfeeding women when the peptide is used topically in rinse off or leave on hair products. This is not medical advice and anyone who is expecting or nursing should confirm suitability with a qualified healthcare provider.
Rh-Polypeptide-105 does not increase photosensitivity, so users do not need to take extra sun protection steps beyond normal daily habits. It is also compatible with most common hair care ingredients such as silicones, plant oils and color preservatives.
Potential Side Effects/Adverse Reactions
Side effects from topical Rh-Polypeptide-105 vary from person to person. The following points cover potential issues, but most users will not encounter them when the ingredient is properly formulated and used as directed.
- Mild scalp redness or warmth
- Itching or tingling immediately after application
- Localized irritation in individuals with protein allergies
- Folliculitis like bumps if product buildup is not washed away
- Contact dermatitis triggered by another ingredient in the same formula
If any of these reactions occur, discontinue use at once and seek guidance from a medical professional.
Comedogenic Rating
Rating: 0 / 5
Rh-Polypeptide-105 is a large water-soluble protein that stays on the hair shaft rather than seeping into facial pores so it has virtually no ability to block follicles or trigger breakouts.
This makes the ingredient suitable for skin or scalps that are prone to acne or folliculitis.
Because it is typically used in low concentrations and is often rinsed away during cleansing there is little chance of residue building up on the skin around the hairline.
Summary
Rh-Polypeptide-105 is a lab made version of the CXCL1 signaling protein used in cosmetics as a hair conditioning agent. It forms a light film on strands that smooths the cuticle boosts shine and helps hair feel thicker while remaining weightless. Although effective its use is still limited to specialty serums masks and high end conditioners so it is not yet a household name.
Current research and consumer feedback point to a strong safety profile with only rare reports of mild irritation. As with any new hair or scalp product it is wise to perform a small patch test before full use to confirm personal tolerance.