Isohexadecane

Overview

Isohexadecane is a branched 16-carbon hydrocarbon. Like its close cousin isododecane, modern cosmetic-grade isohexadecane is largely plant-derived from sugarcane fermentation. It is a clear, low-viscosity, odourless liquid with a very light feel.

The difference between isohexadecane and isododecane comes down to chain length and volatility. Isododecane evaporates in 20-30 seconds; isohexadecane evaporates much more slowly, taking minutes rather than seconds. That means isohexadecane gives you the same dry-touch slip but with more cushioning and a longer skin presence.

In practice, formulators use the two together: isododecane for the instant fast-dry feel, isohexadecane for the residual softness that lingers after the volatile fraction has gone. The two-component approach is what lets a long-wear lipstick or a “second-skin” foundation feel light during application and still feel like skin care hours later.

Shelf life is 2-3 years.

What it does in a formula

• Cushioning slip with a soft, almost powdery finish
• Dispersion vehicle for pigments, waxes, and UV filters
• Anti-greasy behaviour — even at 20-30% it does not feel oily, just smooth
• Stabiliser for high-pigment makeup formulas (it keeps colour even during long wear)

It does not contribute active skin care benefit. Like the other branched hydrocarbons, its value is in the feel and the delivery, not in the ingredient itself.

How to use

Add to the oil phase. More heat-stable than isododecane — it can handle emulsification at 70-75 C without significant evaporation, though it still benefits from being added later in the heating cycle when possible.

Usage rates by product type:

• Foundations and BB creams: 5-15%
• Long-wear lipsticks and lip stains: 10-30%
• Mascara and eyeliner: 5-20%
• Sunscreens (chemical filter-based): 5-15%
• Primers: 5-15%
• Face creams and serums (light texture): 3-8%
• Body lotions: 3-8%

For a foundation, the classic combination is 10-15% isododecane + 10-15% isohexadecane + 5-10% cyclomethicone or replacement. The lipid solvent system that delivers the pigments evenly is built from those three.

Best for / Worst for

Best for: long-wear makeup, foundations, primers, light face creams, sunscreens, products targeting “second-skin” or “weightless” feel, customers who want silicone-free but love the silicone-style feel.

Worst for: rich emollient products, very dry skin formulas, balms and anhydrous treatments where you want a long-lasting cushion (isohexadecane is too volatile for that, even though it is slower than isododecane), unrefined natural-positioned products (it is a precise synthetic molecule, even if plant-derived).

Common pitfalls

Using it interchangeably with isododecane. They have different volatility profiles. If you sub isohexadecane into a long-wear lipstick where you needed full evaporation, you will get a creamier feel but the lipstick will transfer more.

Heat in long heating cycles. Even though it is more stable than isododecane, holding it at 80+ C for 30 minutes will evaporate noticeable product. Reduce heating time when possible.

Treating it as a face oil. It is a delivery vehicle and a feel modifier. Removing it from a formula does not lose any active benefit, just changes texture.

Pricing. Plant-derived isohexadecane is roughly 2-3x the price of petroleum-derived. If you sell to natural-positioned markets it matters; otherwise the petroleum-derived version performs identically.

Substitutes

• Isododecane — closer match for the fast-dry feel, more volatile.
• Hydrogenated polydecene — non-volatile, similar light feel, stays on skin.
• Light dimethicone (5-50 cSt) — closest skin-feel match, but silicone.
• C12-15 alkyl benzoate — drier finish, less cushioning.
• Squalane — natural alternative for the soft feel; loses the powdery dry-down and gains a slick.