The study is aimed at comparing the performance of protocols employing one and two sessions per week, respectively. The study hypothesis claims that there is no significant difference between the performances of the compared protocols.

Inclusion Criteria:

1. Good general health
2. Vasculogenic ED- Erectile Dysfunction, according to physician judgment, for at least 6 months and for no longer than 5 years.
3. International Index of Erectile Function 6 (IIEF-EF) between 17 and 25
4. Satisfactory response to the use of PDE5 (Phosphodiesterase type 5) inhibitors
5. Stable sexual relationship for at least 3 months prior to treatment
6. Minimum of two sexual attempts per month

Exclusion Criteria:

1. Hormonal, neurological or psychological pathology
2. Past radical prostatectomy or extensive pelvic surgery
3. Recovering from cancer during last year
4. Any unstable medical, psychiatric, spinal cord injury and penile anatomical abnormalities
5. Clinically significant chronic hematological disease
6. Anti-androgens, oral or injectable androgens
7. Past radiotherapy treatment of the pelvic region
8. International normalized ratio (INR) > 3 for patients using blood thinners (such as Coumadin)