Psoralen is widely used in the treatment of skin conditions, particularly in phototherapy for psoriasis, vitiligo, and eczema. It works by sensitizing the skin to ultraviolet (UV) light, enhancing the effectiveness of UV radiation in slowing down the excessive growth of skin cells. In vitiligo, psoralen combined with UV light helps repigment the skin by stimulating melanocyte activity. Additionally, psoralen is utilized in the treatment of cutaneous T-cell lymphoma, a type of skin cancer, where it aids in targeting malignant cells under UV exposure. Beyond medical applications, psoralen is also employed in research to study DNA interactions and repair mechanisms due to its ability to bind to DNA and form cross-links under UV light.