A total of 50 male patients who suffered from congestive heart failure were recruited in a double-blind , placebo-controlled trial and randomized to receive an intramuscular ( gluteal ) long-acting androgen injection ( 1mL of testosterone enanthate 250mg/mL ) once every four weeks for 12 weeks or receive intramuscular injections of saline ( 1mL of 0.9 % wt/vol NaCl ) with the same protocol .