Hair serum is left on the lengths and ends after washing or on dry hair, and it is lighter than an oil and absorbs faster. This page holds formulas from Olaplex, L'Oréal, Garnier and Mielle Organics, across shine serums, heat protectants and strengthening oils with rosemary. The rule is to apply to the ends first and work upward, never near the roots, which it would only weigh down. Two or three drops are enough for medium-length hair, since too much reads as greasy rather than glossy. Heat protectants go on before the dryer or the iron, never after. Everything here is 100% authentic, with delivery to all wilayas and cash on delivery.