The mechanism of action and clinical benefits of soy for the treatment of hyperpigmentation

Abstract Background Hyperpigmentation disorders are common and diverse conditions that may require treatment for medical and/or cosmetic reasons. Hyperpigmented lesions can reduce patients’ quality of life, self‐perception, and social and vocational functioning. The most commonly used treatments for hyperpigmentation include topical agents, such as hydroquinone, retinoids and azelaic acid. Objectives Current topical treatments have significant limitations; they often do not produce adequate results and may be limited by adverse effects, such as dermatitis. Soy and soy‐based products have demonstrated a wide range of potential benefits for health and nutrition, including a range of dermatological effects. Methods Research from the last decade has identified multiple mechanisms by which soy‐derived products may affect skin pigmentation, as well as photodamage and photoaging, overall skin health, and even the risk for and progression of skin cancer. Results Preclinical evidence has demonstrated that soy‐derived serine protease inhibitors affect skin pigmentation by inhibiting protease‐activated receptor‐2‐mediated phagocytosis of melanosomes by keratinocytes. Conclusion Soy‐based products containing these serine protease inhibitors may represent a new therapeutic option for dermatological treatment. Indeed, recent evidence from randomized clinical studies supports the safe and effective use of soy products for the treatment of hyperpigmentation.