According to the National Health Institute (NIH) Consensus Development Panel on Impotence, erectile dysfunction (ED) is defined as the persistent inability to achieve and/or maintain an erection sufficient for satisfactory sexual performance.
Causes of erectile dysfunction may be psychological and physiological factors (neurogenic, vascular, endocrine causes). It may also be a side effect of drugs and a symptom of health complications such as diabetes.
Penile erection occurs as a result of increased blood inflow to the penis, engorgement with blood, and decreased outflow of blood from the penis. Primarily, this process is mediated by nitric oxide, which is a neurotransmitter and vasodilator. Nitric oxide is synthesized from L-arginine.
Several researches on the efficacy of L-arginine and nitric oxide on penile erection, fixing erectile dysfunction, have reported positive effects of both chemicals in stimulating and maintaining erection. For example, a study reported that 80 % of men (out of 40, age group 25 – 45) with erectile dysfunction treated with L-arginine (dosage: 1.7 g/ day) and Pycnogenol, an extract from French maritime pine bark (Pinus pinaster), (dosage: 80 mg/day) recovered from their erectile dysfunction after one month of treatment. Pycnogenol, also an antioxidant, stimulates synthesis of nitric oxide from L-arginine. The researchers reported that there was no side effect associated with the supplements.
In another double-blind, placebo-controlled, clinical research on the effect and safety of the combination of 6 g of L-arginine glutamate and 6 mg of yohimbine hydrochloride with that of 6 mg of yohimbine hydrochloride alone and that of placebo alone, for the treatment of erectile dysfunction (ED), it was reported that combined oral administration of the L-arginine glutamate ( 6 g) and yohimbine (6 mg) was effective in improving erectile function in patients with mild to moderate erectile dysfunction (ED).
Herbs and sexuality:
Yohimbe: health benefits and side effects
Ginseng: health benefits and side effects
Ginkgo Biloba: health benefits and side effects
Erectile dysfunction related articles:
What is erectile dysfunction? How does erection occur?
What are the causes of erectile dysfunction?
What are the treatments for erectile dysfunction?
Stanislavov, R. and Nikolova. 2003. Treatment of Erectile Dysfunction with Pycnogenol and L-arginine. Journal of Sex and Marital Therapy, 29(3): 207 – 213.
Basu, A. and Ryder, R. E. J. 2004. New Treatment Options for Erectile Dysfunction in Patients with Diabetes Mellitus. Drugs, 64(23): 2667 – 2688.
Toda, N. Ayajiki, K. Okamura, T. 2005. Nitric Oxide and Penile Erectile Function. Pharmacology and Therapeutics, 106: 233 – 266.
Lebret, T., Hervéa, J. M., Gornyb, P., Worcelc, M. and Botto, H. 2002. Efficacy and Safety of a Novel Combination of L-Arginine Glutamate and Yohimbine Hydrochloride: A New Oral Therapy for Erectile Dysfunction. European Urology 41(6): 608-613.