[LOH (late-onset hypogonadism) or the "aging male"].

Due to lacking evidence of the data about testosterone deficiency of the aging male or LOH (late-onset hypogonadism), this subject is still a challenge for urologists, endocrinologists, and dermatologists or andrologists. This challenge faces basic research as well as clinical investigations. We have to accept responsibility for solving this challenge to better understand and better treat our patients beyond the scope of current guidelines.