AbstractPlasma testosterone was measured in three males and thirty‐six female patients before and after treatment for anorexia nervosa. Low testosterone values were found before treatment, and weight gain was associated with an increase to normal levels. LH, and to a lesser extent FSH, increased during treatment, in accord with previous reports. It is suggested that in males, documentation of the return to normal testosterone levels be made one routine indicator of a return to biological health similar to the return of menstrual cycles for female