Edex (alprostadil) only gives me an erection some of the time.?

Anatomy Counts: Edex (alprostadil) is an injectable option for men who do not respond to, or are not candidates for, oral erectile dysfunction therapy. Improper site injection is the most common cause for it not to work. To ensure safe and effective use of Edex you should be thoroughly instructed and trained in the self-injection technique before you begin intracavernous treatment with Edex at home.