It's the disorder no one wants to talk about, yet according to the Journal of the American Medical Association, 43% of women and 31% of men suffer from sexual dysfunction. Sexual dysfunction is broadly defined as the inability to fully enjoy sexual intercourse. Women generally experience it as a loss of libido (sexual drive) and/or the inability or difficulty in achieving an orgasm. Men experience it as impotence, known technically as erectile dysfunction. Based on hundreds of studies, L-arginine, an essential amino acid and one of the building blocks of proteins in the body, has become known as a safe and effective prosexual nutrient for men and women.
Here's why L-Arginine is a precursor of nitric oxide (NO) in the human body. In the 1990s, scientists discovered that not only is NO an essential compound that helps blood circulation, but it is important to normal sexual function in both men and women. Without arginine there would be no NO, and without NO, men would not be able to have erections.
How L-Arginine works Insufficient blood flow is a major cause of incomplete erection in men.
L-Arginine has been shown to improve blood flow to the genital area by dilating blood vessels and helping the penis to enlarge to its full capacity, thus increasing the size, hardness, and frequency of erections.
Nutritional expert, Dr. Jonathan Wright, explains the mechanism in men: "Molecules of NO are generated when an enzyme called NO synthase (NOS)—which is abundant in the nerve and muscle cells in and around the penis—strips away a nitrogen atom (N) from a passing molecule of the amino acid L-Arginine … and combines it with an atom of oxygen (O)." 2
In other words, in order to produce nitric oxide in the body, a nitrogen atom must combine with an oxygen molecule in the blood. The enzyme called nitric oxide synthase controls this reaction.
L-Arginine has a similar effect in women Higher blood flow makes clitoral and vaginal tissues more sensitive and responsive to sexual stimulation and helps increase the possibility of reaching orgasm. Although there haven't been nearly as many studies done on arginine supplementation in women as in men, one study found that postmenopausal women who took a supplement including L-Arginine experienced heightened sexual response.
Another study involving 77 women of all ages found that after four weeks, 73.5% of the women who took a supplement including L-Arginine experienced greater sexual satisfaction, including heightened desire and clitoral sensation, frequency of intercourse and orgasm, and less vaginal dryness.
Stronger libido ... greater endurance Both men and women report that L-Arginine seems to increase their libido or desire for sex, and some also report that L-Arginine gives them greater endurance and stronger, more powerful orgasms. Reports also suggest that L-Arginine supplements can improve fertility in men who have low sperm counts or poor sperm motility (activity).
Scientific studies The powerful effect of L-Arginine was illustrated in a double-blind, placebo-controlled study published in the British Journal of Urology International in which researchers evaluated the nitric oxide levels of 50 men with erectile dysfunction. The men were given either L-Arginine or a placebo for six weeks. Nine of the 29 men (31%) given L-Arginine reported a significant improvement in their sexual performance. These nine men had low nitric oxide levels at the start of the trial, but their levels doubled by the end of the study.
It is important to note, however, that erectile dysfunction can be caused by a variety of factors, including aging, diabetes and other endocrine disorders. L-Arginine may be effective only in those men whose erectile dysfunction is due to low levels of nitric oxide. In fact, in one study in which the participants suffered from impotence for a variety of reasons, L-Arginine was found to be effective in only 17% of the patients. However, optimal nitric oxide production will ensure optimum erectile function, and for many people with sexual dysfunction not related to an underlying disease, arginine supplements will ensure adequate nitric oxide levels.
Animal studies Studies done on animals provide some evidence for effectiveness as well. In a laboratory study, two groups of rats were given free access to L-Arginine which was dissolved in their drinking water. Both groups had greater serum and penile concentrations of arginine, and exhibited a significant increase in intra-penile pressure or "hardness."
Serum and penile tissue levels of L-Arginine in the treated rats were increased by 64 - 148% compared to control animals. The penile nitric oxide levels also increased nearly 100% in the L-Arginine treated groups compared to the control groups. The researchers concluded that these data support the use of dietary supplements for treatment of erectile dysfunction.
The positive benefits of arginine go beyond sexual enhancement This remarkable amino acid helps build muscle mass, enhance immune function, improve blood pressure, increase memory, and speed wound healing. Arginine-derived nitric oxide has also been found to play a supporting role in the cardiovascular, immune, and nervous systems and has been validated by hundreds of studies.
L-Arginine is essential to several systems in the body. Among its many roles, L-Arginine:
- Is a precursor of nitric oxide (NO)
- Promotes circulation resulting in improved blood flow
- Stimulates the release of growth hormone
- Improves immune function
- Reduces healing time of injuries
- Plays a role in the formation of bone and tendons
- Increases muscle mass, while reducing body fat
- Supports male fertility, improving sperm production and motility
- Reduces risk of blood clots and stroke
- Supports normal blood pressure
- Improves vascular function for patients with angina
- Helps recovery after heart attack
- Helps prevent and treat cardiovascular disease
- Helps reduce growth of cancerous tumors
People with herpes - L-Arginine may increase the severity of outbreaks, but some reports indicate that it may also enhance your immune function enough so you are less likely to get herpes outbreaks. L-Arginine is an excellent supplement for anyone wanting to increase his or her sexual arousal, improve performance, and overall health. The huge advantage this natural and safe supplement has over Viagra is that both men and women can take it, it's considerably less expensive (Viagra costs as much as $10 a pill!), and it's been proven to work in numerous double-blind studies.
Arginine food sources Arginine content (grams /100 gram of food)
Peanuts, Spanish 3.13
Seeds, sunflower seed kernels, dried 2.40
Walnuts, English 2.28
Lentils, raw 2.17
Flax seed 1.93
Beans, kidney, all types, mature seeds, raw 1.46
Pecan nuts 1.18
Beans, French, mature seeds, raw 1.17
Garlic, raw 0.63
Onion, raw 0.10