S100 contains 100% plant-based squalane, which is a saturated form of squalene where the double bonds have been eliminated by hydrogenation.
Thus, squalane is chemically less susceptible to oxidation than squalene. It is also a non-comedogenic moisturiser that is safe for sensitive skin.
Squalene is one of the most abundant lipids produced by human skin cells and is a component of human sebum (13%).
It acts as a singlet oxygen receiver, protecting the skin surface from lipid peroxidation due to exposure to UV and other sources of ionising radiation.1
1. Kohno, Y., Egawa, Y., Itoh, S., Nagaoka, S., Takahashi, M., and Mukai, K. (1995). Kinetic study of quenching reaction of singlet oxygen and scavenging reaction of free radical by squalene in n-butanol. Biochim. Biophys. Acta 1256, 52–56.