Intramuscular testosterone treatment in elderly men: evidence of memory decline and altered brain function.

Context: Recent clinical trials of im testosterone in eugonadal men suggest positive effects on verbal memory, but other studies find no effect.

Objective: Our objective was to determine whether supraphysiological testosterone influences verbal memory and brain function during a verbal memory task in healthy eugonadal older men.

Patients, Design, And Setting: Fifteen cognitively normal men, aged 66-86 yr, participated in a randomized, double-blind, placebo-controlled crossover trial involving 9 months of participation per participant at a hospital-based research facility.