- Alpha hydroxy acids are a well-established skin care hero. Ingredients such a glycolic, lactic and malic acid are renowned for their ability to dissolve the skin’s dulling ‘stratum corneum’ (the oldest, thinnest, top layer of skin) and reveal the younger, more radiant cells beneath. However, these potent acids can irritate skin, especially sensitive complexions – and that’s where The Ordinary’s Mandelic Acid 10% HA comes in. This innovative formulation offers superficial dermal peeling (that’s exfoliation to you and me) that is gentler than other alpha hydroxy acid formulations. How is it gentler, you ask? Simple – the molecular weight of mandelic acid is larger than that of other alpha hydroxy acids and this larger size means that it penetrates the skin more slowly. This makes for a milder exfoliating experience that will suit even the most sensitive complexions, leaving skin smoother, more even and gorgeously glowing. The Ordinary’s (characteristically ingenious) formulation also includes hyaluronic acid, to hydrate and comfort skin while plumping away the look of fine lines. A must-have for sensitive, reactive skin types.