Fildena 25, which contains Sildenafil Citrate as the active ingredient, is primarily used to treat erectile dysfunction (ED) in men by increasing blood flow to the penis. Its effects on muscle strength and endurance, however, are not significant or clinically relevant. Sildenafil Citrate, and other medications in the same class (PDE5 inhibitors), primarily target the enzyme that regulates blood flow in the penis. They do not directly noticeably affect muscle strength or endurance because they do not specifically target skeletal muscle function. Fildena 25 (Sildenafil Citrate) does not have a significant effect on muscle strength or endurance.