Tocopherol.

What it does

It works as a radical scavenger that donates a hydrogen atom to free radicals, protecting cell-membrane lipids (and the oils in a formula) from oxidation. It also acts as a skin-conditioning emollient and is frequently paired with vitamin C.

Benefits

• Lipophilic antioxidant that protects skin lipids and cell membranes from free-radical/oxidative damage
• Helps stabilize formulas by slowing the oxidation (rancidity) of oils
• Provides some photoprotection, and works in synergy with vitamin C for stronger broad-spectrum protection
• Conditions and softens skin as an emollient (alpha-tocopherol is the most active form)

Side effects

• Can cause allergic contact dermatitis in some people, including from derivatives like tocopheryl acetate and tocopheryl linoleate
• Despite popular belief, evidence does not support it improving scars or wound healing (reviews repeatedly find insufficient evidence; INCIDecoder calls the scar claim an 'urban legend')

Who it's for

Most skin types, especially as antioxidant support and alongside vitamin C

Who should be careful