Clinical Assessment of a Supplement of Pycnogenol® and l-arginine in Japanese Patients with Mild to Moderate Erectile Dysfunction

A double‐blind parallel group comparison design clinical study was conducted in Japanese patients with mild to moderate erectile dysfunction to investigate the efficacy of a supplement containing Pycnogenol® and L‐arginine. Subjects were instructed to take a supplement (Pycnogenol® 60 mg/day, l‐arginine 690 mg/day and aspartic acid 552 mg/day) or an identical placebo for 8 weeks, and the results were assessed using the five‐item erectile domain (IIEF‐5) of the International Index of Erectile Function. Additionally, blood biochemistry, urinalysis and salivary testosterone were measured. Eight weeks of supplement intake improved the total score of the IIEF‐5. In particular, a marked improvement was observed in ‘hardness of erection’ and ‘satisfaction with sexual intercourse’. A decrease in blood pressure, aspartate transaminase and γ‐glutamyl transpeptidase (γ‐GTP), and a slight increase in salivary testosterone were observed in the supplement group. No adverse reactions were observed during the study period. In conclusion, Pycnogenol® in combination with l‐arginine as a dietary supplement is effective and safe in Japanese patients with mild to moderate erectile dysfunction. Copyright © 2011 John Wiley & Sons, Ltd.