L-arginine is a semi-essential amino acid, meaning the body normally produces enough on its own. People with certain health conditions, however, can benefit from arginine supplements, according to MayoClinic.com. This protein building block has important functions in the human body. Because of one particular property of arginine, some manufacturers of creams containing this amino acid promote their product as helpful for hair loss. Research is lacking for this purpose, as noted by Dr. Ray Sahelian, who specializes in natural supplements.
L-arginine converts to nitric oxide and causes blood vessel relaxation, known as vasodilation. Arginine may be helpful for treating conditions that benefit from vasodilation, including angina, atherosclerosis, congestive heart failure, coronary artery disease, intermittent claudication and peripheral vascular disease, vascular headaches called by blood vessel swelling, and erectile dysfunction, notes MayoClinic.com. Arginine helps change ammonia in the body to urea so it can be eliminated as waste. This amino acid also is needed for the production of creatine, a substance beneficial for muscles. Because it stimulates protein production, arginine might be useful in wound healing, bodybuilding, increased sperm production and prevention of wasting in patients with serious illness.
People with certain health conditions may not produce enough arginine, according to MayoClinic.com. These include individuals with protein malnutrition, high ammonia production, urea synthesis disorders, infections, burns or who have a high intake of the amino acid lysine. Signs of an arginine deficiency include slow wound healing, constipation, rashes and hair loss. Talk with a physician about whether arginine supplements are advisable.
The theory behind applying arginine cream topically for hair loss is that vasodilators affected by nitric oxide stimulate hair growth, explains Hair Loss Talk. The topical treatment minoxidil works partially by increasing blood vessel dilation.
No studies have been published regarding the effectiveness for arginine cream for hair loss treatment, according to Sahelian. Because poor circulation is often mentioned as a cause of hair loss, people might assume that an arginine cream could restore hair growth by improving circulation, observes Sahelian, but he cautions that it might be difficult for enough arginine to be absorbed to work for this purpose. The theory of decreased blood flow causing male pattern balding and of minoxidil restoring hair growth through increased dilation of blood vessels is too simplistic, according to the Regrowth website.
Many nuts are high in arginine, including peanuts, almonds, Brazil nuts, cashews, filberts, pecans and walnuts, according to MayoClinic.com. Other good sources include sunflower seeds, barley, brown rice, buckwheat, oats, corn, coconut, raisins, chocolate, chicken and other meat and dairy products. As a supplement, a common dose is 2 to 3 g three times per day, although participants in some studies have taken 16 g per day for up to six months, observes MayoClinic.com. Various brands of arginine creams also are available.