Squalane.

What it does

It softens, smooths, and helps seal in moisture without feeling heavy or greasy, and its saturated structure makes it very stable and slow to go rancid.

Benefits

• Lightweight, fast-absorbing moisture that softens without greasiness
• Skin-identical lipid that reinforces the skin's natural moisture barrier
• Non-comedogenic and gentle, friendly to acne- and breakout-prone skin
• Very stable with a long shelf life, so it stays effective in formulas

Side effects

• Rarely irritating; rated very low for irritancy and comedogenicity
• As with any oil, a small number of people may simply not like the feel

Who it's for

All skin types, including dry, sensitive, and acne-prone skin

Who should be careful

No notable cautions; very oily skin may prefer it only as a thin layer

• Squalane - Wikipedia