Squalane

Squalene makes up roughly a tenth of human sebum. Squalane is its hydrogenated form — the same skeleton with no double bonds, so it does not oxidise and go rancid the way squalene does[1].

The evidence

As an emollient it spreads well, reduces water loss and is very rarely comedogenic or sensitising[1]. There is no reason to expect it to do anything dramatic, and it doesn't; it is a good oil.

Use it as the occlusive layer over hyaluronic acidHyaluronic acidModerateSodium Hyaluronate · GlycosaminoglycanPowerful humectant; molecular weight decides whether it sits on the surface or gets in.Open in the Index → or to buffer retinolRetinolStrongRetinol · Vitamin A alcoholThe best-evidenced over-the-counter retinoid for photoageing; now capped at 0.3 % in EU leave-on products.Open in the Index →.