Squalene

Squalene's CosIng-listed function is "skin conditioning - emollient": softens and smooths the skin. This describes a formula role, not a tested finished-product benefit.

Worth separating from its stable cousin squalane. Squalene is unsaturated and oxidises readily on skin into squalene monohydroperoxide, which is comedogenic — more so than several well-known comedogenic cosmetic ingredients. A 2023 study found Malassezia restricta itself drives this oxidation on skin, producing squalene monohydroperoxide that alters the skin barrier — so the yeast and squalene oxidation are mechanistically linked. Squalane (the saturated, hydrogenated form) has none of this — no double bonds to oxidise — and stays generally fine; squalene is the one to patch-test.

Evidence: Limited evidence.

• Comedogenicity of squalene monohydroperoxide in the skin after topical application — oxidised squalene (unlike the saturated, stable squalane) is comedogenic. PubMed 10845185
• Jourdain R, et al. Malassezia restricta-mediated lipoperoxidation — the yeast drives sebum/squalene peroxidation, producing squalene monohydroperoxide that alters the skin barrier. Acta Derm Venereol 2023

Squalene appears in 0% of the 7,133 decoded products in our catalog (32 products). This describes our recorded ingredient lists, not the whole skincare market.

In the products we've decoded, Squalene appears in formulas from Bielenda, Green skincare, Kadalys Skincare, Tonymoly, Belle.

In our decoded catalog, Squalene shows up mostly in moisturizers (17), lip cares (3), serums (3), body lotions (2), eye creams (2), masks (2).

Based on the categories of the decoded products that list it, Squalene shows up mostly in leave-on products (28 of 29 classified). This is derived from product category, not a label fact.

On Korean labels, Squalene is listed as 스쿠알렌.

Typically #16 of a label (middle third) — across 32 decoded labels. Labels list ingredients in descending order only above 1% — position is a rough signal, not a concentration claim.