Arginine is a semi-essential amino acid. Through its metabolite precursor of Nitric Oxide (NO), it is responsible for regulating cellular functions in the body. It dilates and expands the blood vessels in the penis and clitoris, facilitating erections in males and genital responsiveness in females. L-Arginine assists with maximum sexual performance by increasing the supply of nitric oxide in the body, resulting in strong erections and increased sexual functions.  Because of Arginine’s NO stimulating effects, it can be utilized in therapeutic regimens for congestive heart failure, hypertension, and erectile dysfunction. Recent work showed that NO achieves beneficial effects on sperm through improvement of functional status of sperm mitochondria (Jeremy Appleton 2002).

Doses of arginine used in clinical research have varied considerably, from as little as 500 mg per day for oligospermia to as much as 30 g per day for cancer, and premature uterine contractions (B Buzadzic et al. 2015).

In this article, we present the conclusions of few key publications on the subject.

1.    REVIEW:

In a small, uncontrolled trial, men with ED were given 2.8 g arginine per day for two weeks. Forty percent of the men in the treatment group experienced improvement, compared to none in the placebo group. In a larger double-blind trial, men with ED were given 1,670 mg arginine per day or a matching placebo for six weeks. Arginine supplementation was effective in improving ED in men with abnormal nitric oxide metabolism.

Researchers found that feeding an arginine-deficient diet to adult men for nine days decreased sperm counts by approximately 90 percent and increased the percentage of non-motile sperm approximately 10-fold. Oral administration of 500 mg arginine per day to infertile men for 6-8 weeks markedly increased sperm counts and motility in most patients and resulted in successful pregnancies. Similar effects on oligospermia and conception rates have been reported in other preliminary trials.

Reference: B Buzadzic et al. Review: New insights into male (in)fertility: the importance of NO. British Journal of Pharmacology (2015) 172 1455–1467

2.    CLINICAL: A DOUBLE-BLIND, PL CONTROLLED, RANDOMIZED STUDY

Efficacy and safety of L-arginine aspartate 8 g combined with 200 mg of adenosine monophosphate (AA) with placebo (PL) alone for intermittent treatment of mild-to-

moderate erectile dysfunction (ED) were compared. The study design was a double- blind, PL controlled, two-way crossover randomized clinical trial with 26 patients. During each crossover period, separated by a 2-week wash-out period, drugs were administered orally, 1–2 h before sexual intercourse. This study showed that the on- demand oral administration at a high dosage of L-arginine aspartate–adenosine monophosphate combination may be effective in patients with mild-to-moderate ED,

Reference: Y. Neuzillet et al. A randomized, double-blind, crossover, placebo- controlled comparative clinical trial of arginine aspartate plus adenosine monophosphate for the intermittent treatment of male erectile dysfunction. Andrology, 2013, 1, 223–228

1.    CLINICAL: A DOUBLE BLIND RANDOMIZED STUDY

The objective of this study was to assess the efficacy and safety of SX (combination of yohimbine and L-arginine) in the treatment of erectile dysfunction (ED). This trial was a 4-week, double blind study of parallel groups of patients with mild to moderate ED. Forty married male patients with ED of mild-to-moderate severity were eligible to enroll in this study. Patients were randomized to receive one capsule of SX or placebo. This study indicates that SX is safe and effective for the treatment of mild to moderate ED at least in the short-term.

Reference: Shahin Akhondzadeh et al. Efficacy and Safety of Oral Combination of Yohimbine and L-arginine (SX) for the Treatment of Erectile Dysfunction: a multicenter, randomized, double blind, placebo-controlled clinical trial Iran J Psychiatry 2010;5:1

2.    CLINICAL:

Workers evaluated the effectiveness of antioxidant co-supplementation therapy using L-arginine and Pycnogenol® in Japanese men with oligoasthenozoospermia and mild erectile dysfunction (ED). A total of 47 adult males with oligoasthenoteratozoospermia syndrome (OAT) were enrolled. The effectiveness of supplementation with a combination of L-arginine 690 mg and French maritime pine bark extract (Pycnogenol®) 60mg for OAT and ED was investigated. The sperm concentration was enhanced significantly after treatment 2 and 4 months. Significant improvements in the International Index of Erectile Function (IIEF) were observed in the total score of IIEF and domain of Orgasmic Function after 4 months of treatment. This study suggests that the combination of Pycnogenol® and L-arginine (Edicare®) is helpful for infertile men to ameliorate simultaneously quality of sperms as well as erectile functions.

Reference: Yoshitomo Kobori, et al. Improvement of seminal quality and sexual function of men with oligoasthenoteratozoospermia syndrome following supplementation with L-arginine and Pycnogenol®. Archivio Italiano di Urologia e Andrologia 2015; 87, 3.