Ingredient

Butylene glycol

Light hydrator that also helps other ingredients spread and absorb.

What it does

Hydrates · Base of the formula

Evidence

Evidence: Moderate · Some good studies; results vary from person to person.

Often chosen for

Dry, tight-feeling skin

Skin types

Dry, Oily, Combination, Normal

Typical amount

1-10% in a formula

Best time

Morning or evening