Once the vasoactive drugs gained popularity in the early 1980s, the urologists evaluating a patient with erectile dysfunction could quickly move to the test injection of a vasoactive drug into the erectile tissue. The success rate on those two empirical treatments was quite low. If they wanted only a minimal noninvasive therapeutic approach, an empirical injection of the male hormone, Depo-Testosterone, or a trial of an oral agent, such as Yohimbine, were frequently recommended. At this point in the evaluation process, before the availability of Viagra in April of 1998, the overall objective goals of the patient and his partner were discussed. This should be reserved only for the individuals with a marked decrease in testosterone. Every patient does not need a blood prolactin level test. For example, occasionally a patient has an excess of serum blood prolactin that causes a decrease in libido and a decreased blood testosterone level. Most patients with erectile dysfunction do not require an extensive or complicated series of tests before they can receive effective treatment. A blood testosterone level is indicated if the patient is complaining of a significant decrease in libido, or if there is an insufficiency in the normal secondary sexual characteristics.

Laboratory tests should include a urinalysis. Examination of secondary male sexual characteristics, such as testicular size and volume, and the presence and amount of facial hair and genital hair is also helpful. A focused neurological exam with evaluation of the sensation of the penis and the evaluation of the erectile sphincter tone, as well as the size and consistency of the prostate gland, is important.