P Force Fort 150 mg is a generic version of sildenafil, which is also found in other well-known erectile dysfunction medications such as Viagra. Sildenafil works by inhibiting an enzyme called phosphodiesterase type 5 (PDE5), which can restrict blood flow to the penis. By blocking this enzyme, sildenafil helps relax the muscles in the blood vessels, allowing more blood to flow into the penis when sexually stimulated.