Innovative Skin Depigmenting Strategies: A Review

Skin pigmentation results from the melanin production by melanocytes, an essential process for protection against ultraviolet radiation and for maintaining cutaneous homeostasis. Disruptions in this balance lead to pigmentary disorders, such as hyperpigmentation, which is characterized by localized or diffuse darkening of the skin. Its most prevalent forms include melasma, post-inflammatory hyperpigmentation, and solar lentigines, often driven by hormonal, inflammatory, and environmental factors, particularly sun exposure. Despite being clinically benign, these conditions have a significant impact on self-esteem and quality of life. Conventional treatments rely on depigmenting agents such as hydroquinone, retinoids, and corticosteroids, as well as chemical peels, and laser or light-based therapies, frequently used in combination. However, limited efficacy, prolonged treatment durations, and potential adverse effects underscore the need for safer and more effective alternatives. In recent years, research has focused on developing novel approaches, with nanotechnology-based delivery systems and minimally invasive techniques, such as microneedling, standing out as particularly promising fields. In parallel, the growing number of interventional clinical trials reflects an increasing interest in optimizing topical depigmenting strategies. This review summarizes the main types of hyperpigmentation, the depigmenting substances currently used, and emerging therapeutic approaches with potential clinical impact.