What Is Microbial Cellulose/Sr-Spider Polypeptide-3 Hexapeptide-40?
Microbial Cellulose/Sr-Spider Polypeptide-3 Hexapeptide-40 is a hybrid cosmetic ingredient that pairs two different but complementary materials. The first part, microbial cellulose, is a pure form of cellulose made by certain friendly bacteria during fermentation. It forms an ultra-fine web of natural fibers that holds large amounts of water. The second part, Sr-Spider Polypeptide-3 Hexapeptide-40, is a lab-crafted mini protein inspired by the silk proteins found in spider webs. By combining these two elements, formulators get a silky, water-rich film that can sit on the skin’s surface and help keep it smooth and hydrated.
The use of microbial cellulose in skin care started in the medical field, where its breathable yet protective sheets were used as burn dressings. When researchers saw how well it soothed and hydrated damaged skin, beauty brands began adapting it for sheet masks and creams. Spider silk-inspired peptides are a more recent innovation. Scientists mapped the amino acid pattern responsible for silk’s strength and softness, then synthesized short chains of those amino acids. Blending the peptide into the cellulose matrix creates a material that feels elegant, clings gently to the skin and locks in moisture.
Manufacturing starts with a sugar-rich fermentation broth. Specific bacteria grow in the liquid and spin out cellulose fibers at the surface, forming a thick gel-like sheet. After purification and drying, the sheet is soaked in a solution containing the hexapeptide so the fibers trap the peptide within their structure. The finished ingredient is then milled into a fine powder or left as a flexible film, ready to be mixed into water-based formulas.
You will most often find Microbial Cellulose/Sr-Spider Polypeptide-3 Hexapeptide-40 in sheet masks, leave-on moisturizers, overnight creams, soothing gels, anti-aging serums and targeted treatments that promise long-lasting hydration and a soft finish.
Microbial Cellulose/Sr-Spider Polypeptide-3 Hexapeptide-40’s Cosmetic Benefits/Uses
This ingredient pulls double duty by improving how a product feels and how well it keeps the skin hydrated.
- Emollient – fills in tiny gaps on the skin surface to leave it feeling smooth and soft rather than rough or flaky
- Humectant – attracts water from the product and the air, boosting immediate and long-term hydration for a plumper look
- Occlusive – forms a light breathable barrier that slows down water loss so moisture stays in the skin longer
Who Can Use Microbial Cellulose/Sr-Spider Polypeptide-3 Hexapeptide-40
This ingredient is gentle enough for all skin types including oily, dry, normal and combination. Its lightweight water holding network suits dehydrated or mature skin while the breathable film does not feel heavy on oily or acne-prone skin. People with very sensitive or highly reactive skin are usually able to tolerate it because it is free of fragrance and common allergens, though individual results can vary.
Both components are produced without animal-derived materials. The cellulose comes from bacteria grown on plant sugars and the spider peptide is made synthetically in a lab, not harvested from spiders. That makes the ingredient suitable for vegans and vegetarians.
No specific warnings exist for women who are pregnant or breastfeeding. The molecule is large so it stays on the surface rather than entering the bloodstream. Even so, this is not medical advice and anyone expecting or nursing should check with a healthcare professional before adding new skincare.
Microbial Cellulose/Sr-Spider Polypeptide-3 Hexapeptide-40 does not make skin more sensitive to sunlight and can be used morning or night without raising the risk of sunburn.
Potential Side Effects/Adverse Reactions
Reactions to topical Microbial Cellulose/Sr-Spider Polypeptide-3 Hexapeptide-40 vary from person to person. The points below cover possible issues but most users will not experience them when the ingredient is formulated and used correctly.
- Mild redness or stinging in very sensitive skin, usually short-lived
- Allergic contact dermatitis if a person is specifically allergic to cellulose derivatives or certain peptides
- Temporary congestion or small pimples in those prone to clogged pores if the product also contains heavy oils or waxes
- Dry feeling if used in a very low humidity environment without an additional moisturizer on top
If you develop persistent irritation, stop using the product and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 0–1 out of 5. Microbial Cellulose/Sr-Spider Polypeptide-3 Hexapeptide-40 is made up of large water-binding fibers and a lightweight peptide, neither of which sink into pores or leave an oily residue. The cellulose forms a breathable film that sits on the surface while the peptide integrates within that film, so there is minimal risk of pore clogging. This makes the ingredient generally suitable for people who are prone to acne or breakouts. If blemishes appear, they are more likely caused by other richer components in the full formula than by this ingredient itself.
The rating can creep toward 1 if the cellulose matrix is loaded with heavy oils or waxes in a particular product, so always look at the overall ingredient list when assessing acne safety.
Summary
Microbial Cellulose/Sr-Spider Polypeptide-3 Hexapeptide-40 acts as an emollient, humectant and occlusive all at once. The fermented cellulose fibers attract and hold large amounts of water, the spider-inspired hexapeptide nests within those fibers to enhance the silky feel, and together they form a light film that smooths skin, draws in moisture and slows down water loss.
While not yet a household name, the ingredient is gaining traction in sheet masks and high-moisture creams because it delivers a spa-like texture without clogging pores or relying on animal sources. Formulators appreciate its versatility and consumers enjoy the instant softness it provides.
Current data shows it is exceptionally safe for topical use with very low irritation or allergy reports. As with any new skincare item it is wise to patch test first to confirm personal compatibility before applying to the entire face.