Evaluating the effectiveness of a supplement with L-arginine and Pycnogenol for men with erectile dysfunction

This study reviewed the effectiveness and safety of L-arginine and Pycnogenol^® (PAL) in the treatment of male erectile dysfunction (ED). The data showed that the combination of PAL had a significant effect on improving sexual function in patients with mild to moderate ED.

Erectile dysfunction (ED) is the persistent inability to achieve or maintain a penile erection enough for satisfactory sexual performance. It is very common as men age, but it is not a normal part of aging. 

L-arginine is an amino acid which is important for the production of nitric oxide (NO). NO dilates blood vessels to raise blood flow to muscles during exercise. When NO levels are raised, blood vessels of the penis widen and this raises blood flow and causes erections due to its vasodilator effects. Pycnogenol^® comes from the the bark of Pinus pinaster, also known as the maritime pine. It is thought to be an antioxidant and enhances the action of L-arginine through its effects on NO production. It is important to find out if the combination of L-arginine and Pycnogenol^® (PAL) is effective and safe in the treatment of male ED. 

This study reviewed 3 other studies and included overall 184 male patients with ED. Patients were randomly assigned to receive PAL (91 men) or a placebo (93 men) for 1-6 months. The International Index of Erectile Function (IIEF) scale was used to evaluate ED. This scale is a questionnaire used to evaluate the severity of ED. Sexual function and satisfaction, testosterone level, and side events were measured. 

Average scores of the IIEF survey were significantly increased in the PAL group compared to the placebo group. Intercourse satisfaction, sexual desire and overall satisfaction were significantly increased in the PAL group compared to the placebo group. There were no significant differences between treatment groups in testosterone levels. The duration of treatment did not impact the findings. No severe side effects were reported. 

The study concluded that the combination of L-arginine and Pycnogenol^® had a significant effect on improving sexual function in patients with mild to moderate ED.

This study included a small number of participants. More studies with larger groups of patients are needed before conclusions can be made.