Sh-Polypeptide-123: 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 Sh-Polypeptide-123?

Sh-Polypeptide-123 is a lab-designed version of a fragment of human collagen type III, produced through fermentation using the yeast Pichia pastoris. Scientists first identified collagen peptides as valuable skin conditioning agents in the early 2000s, and advances in genetic engineering soon allowed them to recreate precise collagen-like chains without relying on animal sources. To make Sh-Polypeptide-123, researchers synthesize a gene that resembles the one our bodies use to build collagen alpha-1(III). This gene is inserted into Pichia pastoris, which then grows in large stainless-steel tanks, churning out the peptide. After fermentation the peptide is collected, purified and blended into a stable liquid or powder ready for cosmetic use. Because the chain can be up to 1 466 amino acids long it is rich in the same building blocks found in skin, and may include natural crosslinks like disulfide bonds or gentle sugar groups that help it stay flexible and water loving. You will most often see Sh-Polypeptide-123 in serums, sheet masks, anti-aging creams, concentrated boosters and post-procedure soothing gels where it works alongside humectants and antioxidants to reinforce the skin’s surface.

Sh-Polypeptide-123’s Cosmetic Benefits/Uses

This peptide is prized for one clear purpose:

Skin protecting: By mimicking segments of native collagen it forms a lightweight, breathable film on the skin that defends against environmental stressors like pollution and dehydration. This shield helps maintain moisture, supports a smoother feel and can reduce the appearance of fine lines over time.

Who Can Use Sh-Polypeptide-123

Because this collagen-mimicking peptide is lightweight and non-comedogenic it works for dry, normal, combination and oily skin alike. Its film-forming action helps lock in water without feeling heavy, making it a good option even for sensitive or redness-prone complexions that struggle with fragranced or highly acidic products. The only group that may need caution is anyone with a known allergy to yeast fermentation by-products, though such reactions are rare in finished cosmetics.

Sh-Polypeptide-123 is created entirely in a fermentation tank using genetically programmed yeast, with no animal tissue involved at any stage. That makes it suitable for vegans and vegetarians who wish to avoid animal-derived collagen or gelatin often found in traditional peptide blends.

Current data shows no reason this ingredient would pose a special risk to women who are pregnant or breastfeeding when used topically. The molecule is large, sits on the skin surface and is not known to penetrate into the bloodstream. Still, this is not medical advice and anyone who is expecting or nursing should clear new skincare products with their doctor before use.

The peptide does not increase photosensitivity, so it will not make skin more prone to sunburn. Standard daytime sun protection remains important for overall skin health.

Potential Side Effects/Adverse Reactions

Side effects from topical Sh-Polypeptide-123 vary from person to person. The points below outline potential reactions, yet most users who apply a well-formulated product will not encounter these problems.

  • Mild redness or warmth immediately after application
  • Tingling or transient stinging on very sensitive skin
  • Itchiness or small bumps due to individual intolerance to peptides or residual fermentation proteins
  • Contact dermatitis triggered by other ingredients in the finished product such as preservatives or fragrance
  • Rare allergy in people highly sensitive to yeast-derived substances

If any of these effects occur, stop using the product and seek advice from a healthcare professional or dermatologist.

Comedogenic Rating

Rating: 0 – Sh-Polypeptide-123 is a large water-soluble peptide that sits on the skin surface in a thin breathable layer and contains no oily or waxy components that could block pores. It therefore has virtually no potential to trigger comedones and is suitable for people who are prone to acne or breakouts.

Because any finished formula can include richer emollients or silicones that raise the overall pore-clogging risk, always look at the full ingredient list if you are highly blemish-prone.

Summary

Sh-Polypeptide-123 is a lab-crafted fragment of human collagen type III used mainly for skin protecting. It forms a lightweight film that shields against pollution and moisture loss, helping skin stay smooth supple and less lined. Although still a niche addition found mostly in high-end serums masks and post-procedure balms its popularity is increasing as brands search for vegan collagen alternatives.

Current evidence shows it is gentle non-comedogenic and unlikely to irritate most skin types, including sensitive or acne-prone. As with any new cosmetic ingredient it is wise to perform a patch test before full-face use to confirm personal compatibility.

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