Smooth Proof Serum

A sleek leave-in serum from Biolage, Smooth Proof delivers smoothing and frizz control with a silky, non-greasy texture. Ideal for humid climates and for those with unruly, coarse or heat-styled hair. Lightweight and fast-absorbing, it suits color-treated hair. Some variants note fragrance-free and vegan labeling. It layers well under styling creams and offers moderate shine without weighing hair down.