Zenegra 50 mg is a prescription medication that is used to treat erectile dysfunction. It belongs to a class of drugs called phosphodiesterase type 5 inhibitors (PDE5 inhibitors). These drugs work by relaxing the muscles and increasing blood flow to the penis, which helps men achieve and maintain an erection. Zenegra 50 mg is taken orally about 30 minutes before sexual activity. It should not be taken more than once per day.