Martin Ritzén is professor emeritus at the Karolinska Institutet, Stockholm.
After gaining his PhD at the Dept. of Medical Cell Research and Genetics, he founded the division for paediatric endocrinology at the Karolinska University Hospital. His clinical research has focused on male reproduction, sex development, adrenal disorders and growth, resulting in more than 300 publications. He is a past president of ESPE and has received the Andrea Prader Award for outstanding contributions in paediatric endocrinology, and he has been a long-time member and past president of the Medical Nobel Assembly. During recent years, he has been active in forming international regulations for hyperandrogenic women´s participation in sports.