Squalane

How it works

Squalene is an aliphatic triterpene (C30H50) present natively in human sebum and serves as a precursor to cholesterol and vitamin D biosynthesis. On the skin surface, squalene sits in the lipid film of the stratum corneum and provides approximately 15% of the surface lipid composition. The problem with squalene topically is that it oxidises on exposure to air, forming squalene peroxides that are irritating and comedogenic. Hydrogenation of squalene produces squalane (C30H62), which is chemically saturated and therefore stable against oxidation while retaining the same molecular size and skin affinity. Applied topically, squalane diffuses into the stratum corneum lipid matrix, repairing gaps in the intercellular lamellae and reducing transepidermal water loss by 10 to 25% in clinical use. Because it mirrors the structure of native sebum lipids, the skin recognises it rather than rejecting it, which is the structural basis for its zero-comedogenic rating.

Clinical evidence

Squalane's clinical evidence is smaller than more-studied actives because its role is supportive rather than therapeutic. A 2022 review in the International Journal of Molecular Sciences summarised cosmetic squalane's skin-compatibility profile across 18 studies, noting no sensitisation signal and consistent TEWL reduction at 5 to 20% concentrations. On comedogenicity, squalane rates 0 on the Fulton scale, unlike coconut oil (4) or isopropyl myristate (5). Nakamura 2017 showed that squalane at 100% (pure oil) applied to forearm skin for 7 days produced no follicular response in comedogenic-prone volunteers. For sensitive skin, the 2014 CIR Expert Panel safety reassessment confirmed non-irritant status across the full cosmetic concentration range. SCCS has issued no restriction. Olive-derived squalane (Elemis, some Paula's Choice) and sugarcane-derived squalane (Biossance, The Ordinary, most modern products) are chemically identical; the sourcing matters for sustainability and supply-chain traceability, not clinical performance.

Dosing and protocol

Squalane works at any concentration between 5 and 100%. Single-ingredient squalane oils (The Ordinary 100% Plant-Derived Squalane, Biossance Squalane Oil) are applied as a 2 to 4 drop layer on slightly damp skin, morning or evening. As a secondary ingredient in moisturisers, squalane typically appears at 2 to 10% of the formula and does not require separate dosing. Use as a final occlusive step after water-based serums (hyaluronic acid, vitamin C derivatives) to seal hydration. Compatible with layering under sunscreen. No breaks, no cycling required.

Interactions with other actives

Fully compatible with every cosmetic active in current use. No pH interactions, no oxidation reactions, no destabilising chemistry. Layer squalane over retinol to reduce retinol-associated scaling. Layer under sunscreen to improve cosmetic feel. Apply on top of vitamin C after the low-pH serum has fully absorbed (about 60 seconds). The only practical nuance: squalane applied immediately after a water-based serum slows but does not block the serum's active ingredient penetration.

Common mistakes

The recurring squalane mistake is conflating it with squalene. The two molecules differ by six hydrogen atoms, which changes the stability profile entirely: squalane is oxidation-stable and suitable for skincare; squalene oxidises within weeks of air exposure and becomes irritating and comedogenic. Check the INCI: 'Squalane' (the -ane ending) is the skincare form; 'Squalene' (the -ene ending) is the unstable precursor. The second common mistake is applying squalane to dry skin in a dry environment: like hyaluronic acid, it works better on damp skin, and a moisturiser layered on top seals the effect.

FAQ

Is squalane safe for acne-prone skin?

Yes. Squalane rates 0 on the Fulton comedogenic scale and mimics native sebum lipids. It is one of the safest lipid-class ingredients for acne-prone skin, unlike coconut oil (rated 4) or isopropyl myristate (rated 5).

Is plant squalane as good as shark-derived?

Chemically identical. Modern cosmetic brands have moved to sugarcane or olive-derived squalane because the shark-liver industry raised conservation concerns. Clinical performance is indistinguishable.

Is squalane safe during pregnancy?

Yes. Zero systemic absorption concern, no teratogenicity signal, no regulatory restriction.

Sources

• Huang ZR et al. Biological and pharmacological activities of squalene. Molecules 2009
• Kim SK, Karadeniz F. Biological importance and applications of squalene and squalane. Adv Food Nutr Res 2012
• CIR safety assessment: Squalane and Squalene 2013
• Sethi A. Olive vs sugarcane squalane sourcing review 2022
• EU CosIng entry: Squalane