Rh-Polypeptide-5: 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 Rh-Polypeptide-5?

Rh-Polypeptide-5 is a lab made version of a human protein that comes from the gene for transforming growth factor-beta 3. Scientists copy this gene and place it in a harmless strain of E. coli. The bacteria act like tiny factories, fermenting a nutrient broth and turning out the peptide. After fermentation the mixture is filtered and the protein is purified, checked for quality and blended into cosmetic grade solution. Each molecule can contain as many as 412 standard amino acids, sometimes linked by disulfide bonds or carrying small sugar groups called glycans.

Interest in growth factor inspired ingredients rose in the early 2000s when brands searched for new ways to target visible aging. Because Rh-Polypeptide-5 mimics a natural skin messenger yet can be produced consistently in tanks, it soon became a staple in premium skin care launches. Today you will most often spot it in concentrated serums, anti aging creams, eye treatments, sheet masks, post procedure balms and rich moisturizers aimed at boosting overall skin quality.

Rh-Polypeptide-5’s Cosmetic Benefits/Uses

In topical products Rh-Polypeptide-5 serves one main purpose: skin conditioning. By supporting the skin’s surface environment it can help improve hydration, softness, resilience and the look of fine lines, leaving the complexion smoother and more balanced.

Who Can Use Rh-Polypeptide-5

Rh-Polypeptide-5 is considered gentle and is generally suitable for all skin types including dry, oily, combination, sensitive and mature skin. Because it is lightweight and non occlusive it rarely aggravates acne prone complexions or clog pores.

The peptide is produced through bacterial fermentation with no animal derived raw materials, making it appropriate for vegans and vegetarians.

Current data does not suggest any specific risk for pregnant or breastfeeding women when the ingredient is applied topically. Its large molecular size limits penetration beyond the upper skin layers, yet this is not medical advice and anyone who is expecting or nursing should check with a physician before introducing new skincare products.

Rh-Polypeptide-5 does not increase photosensitivity, so it can be used morning or night without elevating the need for extra sun protection beyond the daily SPF that dermatologists already recommend.

Potential Side Effects/Adverse Reactions

Side effects and reactions to the topical application of Rh-Polypeptide-5 can vary from person to person. The points below list potential issues that could arise, though most users will not experience any of them when the ingredient is formulated and used correctly.

  • Mild redness or warmth – usually temporary and resolves after the product dries
  • Itching or tingling – a sign of sensitivity that may lessen with continued use or lower frequency
  • Localized rash or hives – could indicate an allergic response to the peptide or another formula component
  • Dry patches or flaking – more likely if applied alongside strong exfoliants that compromise the skin barrier
  • Eye irritation – may occur if the product accidentally gets into the eyes

If any negative side effect appears stop using the product and seek advice from a qualified healthcare professional or dermatologist.

Comedogenic Rating

Rating: 0/5. Rh-Polypeptide-5 is a large, water-soluble peptide that does not contain heavy oils, waxes or fatty acids that typically block pores. Its size keeps it on the skin surface, and it is metabolically inert, so it does not feed acne-causing bacteria. For these reasons it is viewed as non-comedogenic and is suitable for people who are prone to breakouts. If a product with this peptide still causes blemishes the culprit is likely another ingredient such as a rich butter, silicone blend or fragrance rather than the peptide itself.

Summary

Rh-Polypeptide-5 is used in cosmetics to condition skin, improve hydration, soften texture and give a smoother look to fine lines. It works by imitating a natural growth factor signal that supports the skin surface, helping cells hold water and maintain a healthy barrier.

The peptide has become a favorite in high-end serums, eye creams and post-procedure balms, though its cost and need for careful handling keep it from appearing in every drugstore moisturizer. Still, brands that focus on science-forward anti-aging formulas often spotlight it as a star ingredient.

Current research and consumer feedback show Rh-Polypeptide-5 is low risk, non-comedogenic and well tolerated by all skin types. As with any new skin care product it is smart to patch test first to rule out personal sensitivities and enjoy the benefits with confidence.

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