Manforce 100 is a medication used to treat male erectile dysfunction, which is the inability to maintain and sustain an erection for satisfactory sexual activity. It contains the active ingredient sildenafil citrate, which works by increasing blood flow to the penis and helps men to achieve and maintain an erection when sexually aroused. The effects of Manforce 100 can last up to four hours and it is taken orally with a glass of water about 30 minutes before sexual activity. It should not be taken more than once a day and should be taken with caution if you have certain medical conditions or are taking other medications.