Brand from Taiwan: Dr.Hsieh. The classic version of the essence uses a high-concentration traditional raw material formula design, high concentration, fast effect, directly acting on the skin surface, and relatively high irritation.Suitable for oily, dry, normal and combination skin.Vitamin A derivatives, also known as retinoids, are a class of compounds derived from vitamin A or having structural or functional similarities with vitamin A, including vitamin A alcohol (Retinol), vitamin A Retinoic aldehyde, Retinoic acid and Retinyl esters.Vitamin A derivatives are widely used in medicines and cosmetic skin care products.At present, there are many scientific researches in the world showing that this kind of vitamin A derivatives can improve many kinds of skin problems.Essence oil texture, moisturizes and lightens the skin, smooths fine lines and fades wrinkles.Daily strengthen the structure of the skin base, improve firmness and elasticity, help the skin improve the tolerance of A-alcohol skin c