Penegra 100 is a medication containing sildenafil citrate, a phosphodiesterase type 5 (PDE5) inhibitor used to treat erectile dysfunction (ED) in men. It works by increasing blood flow to the penis during sexual stimulation, facilitating the ability to achieve and maintain erections. Penegra should be taken approximately 30 minutes to 1 hour before anticipated sexual activity. It works best when taken on an empty stomach or with a light meal, as fatty meals can delay its onset of action.