What Is Sr-Silkworm Polypeptide-2?
Sr-Silkworm Polypeptide-2 is a blend of short-chain proteins obtained from the silk produced by the Bombyx mori silkworm. Rich in amino acids such as serine, glycine and alanine, the ingredient forms a lightweight film that feels soft and breathable on skin. Silk proteins have been prized in Asia for centuries for their smooth feel, but it was not until recent advances in extraction and purification that smaller polypeptide fractions like Sr-Silkworm Polypeptide-2 became available for modern skin care.
To create the ingredient, raw silk fibers are first cleaned to remove natural waxes and pigments. The fibers are then gently hydrolyzed with food-grade enzymes, breaking the long fibroin chains into shorter, water-soluble polypeptides. These fragments are filtered, concentrated and spray-dried into a fine powder ready for use in cosmetic labs. No harsh solvents are required, which helps preserve the amino acid profile and keeps the material skin friendly.
Thanks to its light texture and moisturizing feel, Sr-Silkworm Polypeptide-2 appears in a variety of water-based formulas such as hydrating serums, sheet masks, anti-aging creams, makeup primers and leave-on hair or scalp treatments. It can be paired with humectants like glycerin or hyaluronic acid to boost softness or layered with botanical extracts for added sensory appeal.
Sr-Silkworm Polypeptide-2’s Cosmetic Benefits/Uses
In topical products Sr-Silkworm Polypeptide-2 serves one main purpose.
Skin conditioning: The polypeptide creates a thin, invisible layer that binds water to the skin surface helping it feel smoother and more supple. This film reduces moisture loss throughout the day which can soften fine lines and improve overall texture. Because the molecule is lightweight it absorbs quickly without leaving a greasy after-feel making it suitable for daily moisturizers as well as richer night creams.
Who Can Use Sr-Silkworm Polypeptide-2
Sr-Silkworm Polypeptide-2 is gentle enough for most skin types including dry, oily, combination and sensitive skin. Its lightweight feel suits acne-prone complexions because it conditions without clogging pores, while the softening film comforts dry or mature skin.
People who follow vegan or strict vegetarian lifestyles may choose to avoid this ingredient since it is sourced from silkworm silk. Anyone looking for plant-based formulas should check labels for silk or animal-derived proteins.
Current research shows no specific issues for women who are pregnant or breastfeeding when using skincare products that contain Sr-Silkworm Polypeptide-2. This is not medical advice and those who are pregnant or nursing should always run any product past a doctor to be safe.
The ingredient does not make skin more sensitive to sunlight so it is not considered photosensitising. It can be used morning or night alongside daily sunscreen.
Those with a known silk or insect protein allergy should proceed carefully or choose an alternative.
Potential Side Effects/Adverse Reactions
Responses to topical Sr-Silkworm Polypeptide-2 differ from person to person. The following is a list of potential side effects which are unlikely for most users when the ingredient is correctly formulated.
- Mild redness or stinging on very reactive skin
- Allergic contact dermatitis in individuals sensitive to silk proteins
- Itchiness or small bumps if the product is layered too heavily on oily areas
- Eye irritation if the formula accidentally gets into the eyes
If any discomfort or visible reaction occurs stop using the product and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 0–1. Sr-Silkworm Polypeptide-2 is water soluble and forms a breathable film that rinses away easily so it rarely blocks pores. It lacks heavy oils or waxes that typically cause congestion. For most users, including those with oily or combination skin, it should not trigger breakouts. Individuals with highly clog-prone skin can generally consider it safe, though overall formula and personal response still matter.
Because the polypeptide is often paired with humectants rather than occlusive agents, its presence in a product usually signals a lighter texture. If the finished product also includes richer butters or silicones, those other ingredients may influence comedogenic potential more than the silk protein itself.
Summary
Sr-Silkworm Polypeptide-2 works as a skin-conditioning agent that smooths and softens by creating a moisture-binding film on the surface. The amino acid-rich polypeptides attract water, reduce transepidermal loss and leave a silky after-feel without heaviness.
While silk derivatives have a long history in Asian beauty care, this specific small-chain version is still a niche addition in global formulas, appearing mainly in mid-to-premium serums masks and creams where a refined texture is desired.
Current data shows the ingredient is well tolerated for most skin types with a very low risk of irritation or pore clogging, though anyone with a known silk allergy should avoid it. As with any new cosmetic, doing a quick patch test before full use is a smart precaution.