What Is Sh-Polypeptide-46?
Sh-Polypeptide-46 is a lab made version of a natural human protein known as interferon alpha-2. Scientists recreate the exact gene that codes for this protein and insert it into a strain of E. coli used for industrial fermentation. Inside the bacteria the gene acts like a set of instructions telling the cells to build the peptide chain of up to 188 amino acids. After the fermentation run technicians harvest the broth, isolate the protein, then purify it through a series of filtration and chromatography steps to remove bacterial residues and ensure cosmetic-grade quality. Because the sequence matches the human original it can fold into its native shape, including any disulfide bridges that help keep the structure stable. Since it is made without animal material it is considered vegan friendly and has a low risk of transmitting contaminants.
Interest in using bio-engineered peptides in cosmetics grew in the early 2000s when formulators began looking for skin friendly actives that could signal cells rather than simply coat the surface. Sh-Polypeptide-46 entered the market as brands searched for ways to mimic the soothing effects of interferon without the regulations attached to drug use. Today you might spot it in serums, sheet masks, post-procedure calming gels, high-end moisturizers and targeted anti-aging treatments that promise to strengthen the skin barrier and boost overall comfort.
Sh-Polypeptide-46’s Cosmetic Benefits/Uses
Its primary role in topical formulas is:
- Skin conditioning – helps maintain a healthy feel and appearance by supporting the skin’s natural defense processes, reducing visible irritation and improving softness which can leave the complexion looking calmer and more even
Who Can Use Sh-Polypeptide-46
Because it is a lightweight water-soluble peptide with no occlusive oils or waxes, Sh-Polypeptide-46 is generally suitable for all skin types including oily, combination, dry and mature skin. Sensitive or reactive skin often tolerates it well thanks to its calming profile, though anyone with a history of allergies to fermented ingredients should proceed with extra care.
The peptide is produced entirely through microbial fermentation with no animal-derived inputs, so it aligns with vegan and vegetarian lifestyles.
Current data does not show that topical Sh-Polypeptide-46 penetrates deeply enough to affect pregnancy or nursing. Still, this is not medical advice and anyone who is pregnant or breastfeeding should confirm product choices with a qualified healthcare provider.
The ingredient is not known to generate photosensitivity, so routine daytime use is acceptable provided broad-spectrum sunscreen is already part of your skin care habits.
Potential Side Effects/Adverse Reactions
Individual responses to Sh-Polypeptide-46 can differ. The following list covers potential side effects that might occur in rare cases. Most people will not experience these issues when the ingredient is formulated and used as intended.
- Localized redness or flushing
- Mild stinging or tingling right after application
- Itchy or patchy dryness if the formula contains a high concentration
- Allergic contact dermatitis in those sensitized to proteins or fermentation byproducts
- Exacerbation of existing eczema or rosacea for a small subset of highly reactive skin
If any of these reactions develop discontinue use and seek advice from a medical professional or dermatologist.
Comedogenic Rating
Rating: 0 (non comedogenic). Sh-Polypeptide-46 is a large, water-soluble peptide that does not contain oils, waxes or fatty acids that can clog pores. It sits on the skin surface, then gradually breaks down into amino acids that are easily rinsed away, so there is virtually no risk of trapped sebum or blocked follicles.
Because of this, the ingredient is generally suitable for people who are prone to acne or frequent breakouts.
The final product’s overall pore-friendliness will still depend on the whole formula, so look at the full ingredient list if congestion is a concern.
Summary
Sh-Polypeptide-46 is a lab grown copy of human interferon alpha-2 that serves as a skin-conditioning agent. When applied topically it helps calm visible redness, supports the skin’s natural defense signals and leaves the surface feeling softer and more balanced. It delivers these benefits without adding heaviness, thanks to its lightweight water-based profile.
While not as widely known as collagen peptides or popular anti aging actives, it has carved out a niche in premium serums, post-procedure soothing gels and sensitive skin formulas where a gentle calming effect is prized.
Current research indicates a solid safety record with low irritation potential and no comedogenicity. As with any new cosmetic ingredient, perform a small patch test when you first try a product containing Sh-Polypeptide-46 to make sure your skin agrees with it.