Letterlife is the first tool allowing females with ADHD to visualize the interplay of hormones, ADHD-symptoms, and everyday functioning across the menstrual cycle and the female lifespan. By tracking hormonal fluctuations, ADHD-symptoms, personal challenges, and pharmacological treatment we empower women, encourage self-efficacy and improve self-care. Today females are diagnosed 5 years later than men and untreated ADHD results a 13 year shorter life expectancy. Letterlife constitutes a data driven, gender sensitive base for shared health care decision making. The key lies in linking individualized data to health care registers, providing women with the guidance needed to navigate the complex interplay between mental and reproductive health.