For ERECTILE DYSFUNCTION, the amino acid L-arginine boosts nitric oxide production and blood flow to the erectile tissues improving the ability to achieve maintain an erection, and prolonging its duration. Research shows that men who take L-arginine for two to six months score significantly higher on the International Index of Erectile Function: This is a set of fifteen questions rating the frequency of attaining and keeping an erection, and the level of satisfaction with penetration and intercourse. In addition, the research subjects’ testosterone levels increased markedly.
An erection and sexual arousal is a result of complex interaction between multiple systems including the nervous system, muscles, hormones, and emotions. Clinical studies show that erectile dysfunction (ED) is a symptom, rather than a condition. It is mostly due to reduced opening of pelvic blood vessels, and sometimes less elasticity of arteries so that they cannot expand fully. Stress or diabetes can also impede these systems and their function. Plaque buildup in the pelvic and penile arteries is responsible for ED in about 40% of men over 50 years old.
L-arginine is a semi-essential amino acid meaning that it can be produced by the body, but its production depends on many different factors such as age, mental or physical stress. A number of health situations require higher amounts. Though adult bodies make some arginine, and small amounts are found in nuts, seeds, and legumes, it needs to be consumed through supplementation to reach adequate levels to help male sexual functions. L-arginine was first isolated from a lupin plant seedling extract in 1886 by the Swiss chemist Ernst Schulze.
L-Arginine works in three main ways:
- It improves blood flow as vessels open up;
- it reduces clotting risk, discouraging tiny blood cell or platelet clumps that could impede blood flow to the penis;
- L-arginine helps blood become less viscous, so that it flows with greater fluidity. Arginine accomplishes this because it is an immediate precursor, or building block, for the body to make nitric oxide, which works to encourage blood vessels to open wider, improving blood flow.
Nitric oxide occurs in the cells of almost all types of organisms, ranging from bacteria to plants, fungi, and animals. In mammals, nitric oxide is a natural blood vessel-opening molecule. It is made within cells from L-arginine, oxygen, and a co-factor called NADPH. The inner cells that form the lining of blood vessels, the endothelium, send nitric oxide as a signaling compound to the surrounding smooth muscle of the vessels. This smooth muscle relaxes, the vessels open up, which is vasodilation, and blood flow increases. Nitric oxide also helps blood vessel health by inhibiting the over-development of vascular smooth muscle.
The penis has two chambers called the corpora cavernosa, which run the length of the organ. These contain a maze of blood vessels shaped like cavernous spaces, resembling a sponge. The urethra, a channel for urine and sperm, runs along the underside of the corpora cavernosa. The erectile tissue of the corpora cavernosa is supplied by two main arteries and several veins and nerves. An erection begins with sensory and mental stimulation, when nerve messages begin to stimulate the penis. Impulses from the brain and local nerves cause the tiny muscles in blood vessels of the corpora cavernosa to relax and open up. Blood rushes in through the cavernosus arteries to fill spaces in the spongy tissue. This creates pressure in the corpora cavernosa, making the penis expand and become erect. The blood then gets trapped under high pressure, creating an erection. The tunica albuginea, a membrane surrounding the corpora cavernosa, helps to trap the blood in the corpora cavernosa, sustaining the erection. An erection is reversed when muscles in the penis contract, stopping the inflow of blood and opening outflow channels.
Penile erection requires nitric oxide to trigger relaxation of the cavernous smooth muscle. Studies of tissue levels of nitric oxide on smooth muscle relaxation revealed that penile erection is mediated by nitric oxide.2,3 Nitric oxide also limits platelet aggregation and white blood cell adhesion to the endothelium, ensuring swift blood flow and reducing clot risk. Sildenafil citrate, or Viagra, stimulates erections by enhancing nitric oxide signaling in the penile blood vessels.
Double-blind research verifies that L-arginine improves the ability to keep an erection during intimacy for 31 to 87% of men. One study included 50 men with confirmed organic Erectile Dysfunction (ED) who were given a high dose of 5,000mg of L-arginine per day for six weeks. Researchers concluded that “oral administration of L-arginine in high doses seems to cause significant improvements in sexual function in men with organic ED if they have decreased nitric oxide excretion or production.”4
L-arginine has produced excellent results for male patients at our clinic with erectile problems. Each nitric acid molecule produced by the body or from supplemental L-arginine is rapidly metabolized so blood levels drop fast. We recommend a sustained-release L-arginine preparation, in a base of slow-release methylcellulose, to maintain ample tissue levels of L-arginine over 24 hours with just 500mg two times daily.
L-arginine in a base of slow-release methylcellulose, 500mg two times daily, with or between meals; or as directed by your healthcare provider.
- Andrew PJ, Mayer B (Aug 1999). “Enzymatic function of nitric oxide synthases.” Cardiovascular Research. 43 (3): 521–31.
- Ignarro, Louis J., et al. “Nitric oxide and cyclic GMP formation upon electrical field stimulation cause relaxation of corpus cavernosum smooth muscle.” Biochemical and biophysical research communications 170.2 (1990): 843-850.
- Burnett, Arthur L., et al. “Nitric oxide: a physiologic mediator of penile erection.” Science 257.5068 (1992): 401-403.
- Chen, J., et al. “Effect of oral administration of high-dose nitric oxide donor L-arginine in men with organic erectile dysfunction: results of a double-blind, randomized, placebo-controlled study.” BJU int 83.3 (1999): 269-73.