One major medication for treating erectile dysfunction and impotence in males is malegra 25. Sildenafil Citrate, a component in this medication, aids in giving men a powerful erection during sexual activity. This medication relaxes the muscles and helps men's penile tissues receive more blood flow. Take this medication half an hour before sexual activity. This medication can be used either before or after food. This medication has a six-hour half-life. As prescribed by your physician, you should take this medication. For additional information, go to doublepills.com.