Erectile Dysfunction I am 25 years old. I have erectile dysfunction after my penile doppler test is completed. I have been masturbating since the age of 15 years. I can not ever maintain hard erection during sexual intimacy. I have tried as per medical practitioner statement megalis20 but it gives satisfaction only for 1 day. I have nit gain hard erection and if I get it then penis will go again weak. Please kindly solve this problem. Kindly tell me how to increase testosterone level and nitric oxide. I have read your previous articles so I know I have the problem of blood flowing during sexual intimacy.