C13-15 alkane is a lightweight, colorless oil used in skincare and haircare products. It acts as an emollient and solvent, giving products a silky, dry finish similar to silicones but with a simpler chemical profile. You’ll most commonly encounter it under the trade name Hemisqualane, marketed by several ingredient suppliers for use in serums, moisturizers, hair oils, and makeup.
What It Actually Is
Alkanes are among the simplest molecules in chemistry: chains of carbon and hydrogen atoms with no reactive groups attached. The “C13-15” in the name tells you the chain length. Each molecule contains between 13 and 15 carbon atoms linked together, making it a medium-weight hydrocarbon. This puts it in a sweet spot where it’s light enough to absorb quickly into skin but heavy enough to leave a smooth, conditioning feel.
The version used in cosmetics is typically a branched alkane, meaning the carbon chains aren’t perfectly straight. Branching matters because it keeps the ingredient liquid at room temperature and prevents it from feeling waxy or heavy. The European Commission’s cosmetic ingredient database (CosIng) lists C13-15 alkane with a registered function as a solvent, though in practice formulators also use it as an emollient and a carrier for other active ingredients.
How It’s Made
The most well-known version of C13-15 alkane on the market is Neossance Hemisqualane, which is derived from sugarcane through a fermentation process. Sugarcane is converted into a precursor molecule called farnesene, which is then hydrogenated (combined with hydrogen) to produce the final alkane. This plant-based origin is a key selling point, since many traditional emollients in cosmetics come from petroleum or are synthetic silicones.
The “hemisqualane” nickname comes from its relationship to squalane, another popular skincare oil. Squalane has 30 carbon atoms; hemisqualane has roughly half that, which is why it feels noticeably lighter on the skin.
What It Does in Products
C13-15 alkane serves several roles in a formula. As an emollient, it softens skin by filling in the tiny gaps between skin cells, reducing moisture loss without feeling greasy. As a solvent, it helps dissolve other ingredients and keeps formulas uniform. It spreads easily and evaporates partially after application, which gives products that “dry oil” sensation many people prefer in serums and lightweight moisturizers.
In haircare, it’s used to add shine and reduce frizz without weighing hair down. It performs similarly to cyclomethicone and other volatile silicones, which is why brands marketing “silicone-free” products often reach for C13-15 alkane as a replacement. It also works well as a base in cleansing oils, where it helps dissolve makeup and sunscreen.
Safety and Skin Compatibility
C13-15 alkane has a straightforward safety profile. Alkanes are chemically inert, meaning they don’t react easily with other substances, including the proteins and lipids in your skin. This makes them unlikely to cause irritation or allergic reactions. The ingredient is non-comedogenic for most people, so it’s generally well tolerated even on acne-prone skin, though individual responses always vary.
Because it’s a hydrocarbon rather than a fatty acid or plant oil, it doesn’t oxidize or go rancid the way some natural oils do. This gives it a long shelf life and makes products containing it more stable over time.
Environmental Considerations
Simple hydrocarbons like C13-15 alkane are readily biodegradable. Microorganisms in soil and water break down straight and branched alkanes efficiently, and environmental concentrations from cosmetic use tend to stay low. The sugarcane-derived versions carry the additional appeal of coming from a renewable feedstock rather than fossil fuels, though the fermentation and hydrogenation steps still require energy inputs.
It’s worth noting that the EPA’s environmental data on similar carbon-chain-length compounds (specifically alcohols in the C13-C15 range) shows aquatic toxicity drops off sharply above 13-14 carbon atoms, because these molecules become too insoluble in water to reach harmful concentrations. Alkanes are even less water-soluble than their alcohol counterparts, making significant aquatic toxicity unlikely at real-world exposure levels.
Where You’ll See It on Labels
On an ingredient list, look for “C13-15 Alkane” as the INCI (International Nomenclature of Cosmetic Ingredients) name. Some brands list it by trade name in their marketing materials, with Hemisqualane being the most common. You’ll find it in a wide range of products: facial oils, hair serums, primers, liquid foundations, micellar waters, and body lotions. It typically appears in the first third of the ingredient list, indicating it makes up a significant portion of the formula rather than serving as a trace additive.
If you’re comparing it to other lightweight emollients, it sits between volatile silicones (which evaporate almost completely) and heavier oils like jojoba or argan (which leave more residue). For people who want a clean, fast-absorbing feel without silicones or heavy plant oils, C13-15 alkane hits that middle ground.