What Is C16-36 Alkyl Stearate?
C16-36 Alkyl Stearate, also called C16-36-alkyl octadecanoate, is an ester made by joining stearic acid (a fatty acid found in vegetable oils and animal fats) with a blend of long-chain alcohols that range from 16 to 36 carbon atoms. This pairing creates a wax-like material that is solid at room temperature yet softens on contact with skin. Cosmetic chemists first explored these kinds of esters in the 1970s while searching for plant-based options that could replace mineral oil and heavy waxes. Today most suppliers make C16-36 Alkyl Stearate by hydrogenating natural oils, then separating the fatty acids and alcohols before combining them under heat with an acid or enzyme catalyst. The finished ingredient is purified, cooled and milled into fine flakes or beads.
Its mild touch and flexible texture make it popular in a wide range of products. You will often find it in moisturizers, creamy foundations, lipsticks, sun care products, hair conditioners and solid cleansing bars. It helps these formulas feel richer without being greasy and also improves the payoff and wear of color cosmetics.
C16-36 Alkyl Stearate’s Cosmetic Benefits/Uses
As a skin-conditioning agent, C16-36 Alkyl Stearate forms a light breathable film that smooths rough spots, softens the surface and locks in moisture. It gives creams and lotions a silky glide so they spread evenly, adds a cushioned feel to makeup and helps balms stay put longer.
Who Can Use C16-36 Alkyl Stearate
C16-36 Alkyl Stearate is generally well tolerated and suits most skin types including normal, dry and mature skin thanks to its emollient yet non greasy finish. People with very oily or acne prone skin may find rich formulas that contain high levels of this waxy ester feel heavy or could sit on the surface, so lightweight products are a better pick in that case.
The ingredient itself can be made from either plant or animal sources. Most cosmetic suppliers produce it from hydrogenated vegetable oils which makes it suitable for vegans and vegetarians, but because sourcing can vary it is best to look for brands that specify a plant origin or carry vegan certification.
Current safety data indicate no issues for pregnant or breastfeeding women when the ingredient is used topically in cosmetics, though this is not medical advice. Anyone who is expecting or nursing should run any skincare product past a qualified health professional just to be safe.
C16-36 Alkyl Stearate does not cause photosensitivity so it will not make skin more likely to burn in the sun. It also has no known interactions with common active ingredients such as retinoids or acids.
Potential Side Effects/Adverse Reactions
Side effects from the topical use of C16-36 Alkyl Stearate can vary from person to person. The points below outline potential reactions, but they are uncommon and most users will not experience them when the ingredient is used correctly in a well-formulated product.
- Mild skin congestion in individuals who are highly prone to clogged pores
- Transient redness or stinging on very sensitive or compromised skin
- Allergic contact dermatitis in rare cases of individual hypersensitivity
- Folliculitis if thick products trap heat and sweat in hair-bearing areas
- Eye irritation if the raw material or a product containing it is accidentally rubbed into the eyes
If any negative reaction occurs discontinue use immediately and consult a healthcare professional.
Comedogenic Rating
Rating: 2 out of 5. C16-36 Alkyl Stearate is a long-chain fatty ester that sits on skin as a thin breathable film rather than sinking deeply into pores. Its waxy nature can slow down evaporation of sweat and sebum which may contribute to minor congestion in people who clog easily, but the large molecular size makes it less likely to penetrate and block follicles compared with shorter fatty acids. For most users it is considered low to moderately comedogenic and is generally fine for acne-prone skin when used in lightweight or rinse-off formulas. Formulations rich in the ester plus other heavy oils could raise the likelihood of breakouts so product texture and the complete ingredient list matter.
Summary
C16-36 Alkyl Stearate is an emollient and skin-conditioning agent that smooths rough patches, locks in moisture, improves spreadability and boosts the staying power of makeup. It achieves these effects by forming a flexible wax-like film that softens the skin surface while reducing water loss. Although not as famous as ingredients like shea butter or squalane, it quietly appears in a wide range of creams, sticks, sunscreens and cleansing bars because it offers a rich feel without a greasy aftertouch.
Current research and industry use show it is safe for topical application with very low risk of irritation or sensitization. As with any new cosmetic ingredient it is wise to patch test a product containing C16-36 Alkyl Stearate before full-face use so you can spot any unexpected reaction early.