MTS Science – Low Intensity Shock Wave (LiSW) has emerged as a therapy for vasculogenic erectile dysfunction (ED). Mechanism may be related to angiogenesis, release of growth factors and/or recruitment of stem cells. Several sham controlled studies have shown improvement in peak arterial velocity and efficacy in the 60-65% range depending on the definition. The initial protocol of twice weekly treatments for 3 weeks with a rest period and repeat has remained the standard, although this can be very inconvenient for patients. We wished to study the efficacy and safety of LiSW using a modified protocol of 4 weekly treatments.