Suhagra 100 works by inhibiting the enzyme PDE5, which normally breaks down cGMP, a substance that helps blood vessels in the penis relax and expand. By increasing cGMP levels, sildenafil allows for increased blood flow, leading to a stronger and longer-lasting erection. The effects of Suhagra 100 can last for 4 to 6 hours, meaning it provides a window of opportunity for sexual activity. However, sexual stimulation is still necessary for the drug to work—it does not cause an erection without arousal.