Intramuscular TRT is more effective than transdermal formulations at increasing LBM and improving muscle strength  in middle-aged and older men , particularly in the lower extremities
BACKGROUND Inconsistent fat-free mass ( FFM ) and muscle strength responses have been reported in r and omized clinical trials ( RCTs ) administering  testosterone replacement therapy ( TRT ) to middle-aged and older men .
Our objective was to conduct a meta- analysis to determine whether TRT improves FFM and muscle strength in middle-aged and older men and whether the muscular responses vary by TRT administration route .
A randomized, double-blind, placebo-controlled trial of testosterone gel on body composition and health-related quality-of-life in men with hypogonadal to low-normal levels of serum testosterone and symptoms of androgen deficiency over 6 months with 12 months open-label follow-up
Introduction : The clinical significance of low to low-normal testosterone ( T ) levels in men remains debated . Aim : To analyze the effects of raising serum T on lean body mass ( LBM ) , fat mass ( FM ) , total body mass , and health-related quality -of-life ( HRQoL ) . Methods : R and omized , double-blind , placebo-controlled study . Men , aged 50–80 years , with serum total T<15 nmol/L and bioavailable T < 6.68 nmol/L , and a Aging Males ’ Symptoms ( AMS ) total score > 36 , received 6 months treatment with transdermal 1 % T gel  ( 5–7.5 mg/day ; n = 183 ) or placebo gel ( n = 179 ) , followed by 12 months open-label with T in all . Results : After 6 months , LBM increased in T- treated patients by 1.28 ± 0.15 kg ( mean ± SE ) and FM decreased by 1.16 ± 0.16 kg , with minor changes with placebo ( LBM + 0.02 ± 0.10 kg and FM −0.14 ± 0.12 kg ; all p < 0.001 , T group vs. placebo ) . Changes were largely similar across subgroups of age , baseline total testosterone , and baseline BMI . Total HRQoL improved compared with placebo ( p < 0.05 , T group vs. placebo ) . Conclusions : Six months 1 % T gel improved body composition and HRQoL  in symptomatic men with low to low-normal T , with further improvements over the following 12 months
Intramuscular TRT is more effective than transdermal formulations at increasing LBM and improving muscle strength  in middle-aged and older men , particularly in the lower extremities
BACKGROUND Inconsistent fat-free mass ( FFM ) and muscle strength responses have been reported in r and omized clinical trials ( RCTs ) administering  testosterone replacement therapy ( TRT ) to middle-aged and older men .
Our objective was to conduct a meta- analysis to determine whether TRT improves FFM and muscle strength in middle-aged and older men and whether the muscular responses vary by TRT administration route .