Kamagra 100 is a medication used primarily to treat erectile dysfunction (ED) in men. It contains sildenafil citrate, the same active ingredient found in Viagra. Kamagra 100 works by increasing blood flow to the penis during sexual stimulation. Sildenafil is a PDE5 inhibitor, which means it blocks the enzyme that causes blood to leave the penis after arousal. By relaxing blood vessels and enhancing blood circulation, Kamagra 100 helps a man achieve and maintain a firm erection. It typically begins working within 30 to 60 minutes after intake and can last for up to 4 to 6 hours.