The pilosebaceous unit is a major target of androgens in human skin. Sebaceous glands are located in the dermis and their ducts end at the terminal portion of the hair follicles. The sebaceous secretion produced by those glands is a complex mixture of lipids containing triglycerides, free fatty acids, cholesterol and esters. The enzymes 5-alpha-reductase (5?-redutase) and 17-beta-hydroxysteroid diidrogenase (17?-HSD) are directly or indirectly responsible for converting testosterone to dihydrotestosterone (DHT), an androgen which has greater biological activity in the tissues, which favors the sebum secretion and acne formation. Besides the sebum secretion, the pathogenesis of acne also involves an inflammatory response and proliferation of bacteria aggravating injury. Therefore, oily skin is more likely to develop inflammatory processes such as acne and seborrhoea requiring products to control this oil. In this study, we evaluated the in vitro efficacy of an active ingredient in anti-sebum activity and in the protection of skin barrier in cultured human fibroblasts and keratinocytes. In fibroblast culture, the active ingredient promotes a significant reduction in the production of 5?-reductase and 17?-HSD, in the presence or absence of testosterone. Interestingly, the active ingredient promoted further reductions in the production of 5?-reductase and 17?-HSD when incubated concurrently with testosterone and finasteride, indicating an additive or synergistic action in the control of oiliness. In relation to skin barrier properties, the active ingredient promoted significant increases in the synthesis of envelope protein involucrin, keratin 10 and keratin 14, indicating an involvement in maintaining stratum corneum integrity. These results demonstrate a significant anti-sebum and anti-androgenic activities of the active ingredient, since the enzymes 5?-reductase and 17?-HSD are implicated in the induction of DHT synthesis stimulating sebum production.