L-Arginine was first isolated in 1886. In 1932, scientists learned that L-arginine is needed to create urea, a waste product that is necessary for toxic ammonia to be removed from the body. In 1939, researchers discovered that L-arginine is also needed to make creatine. Creatine breaks down into creatinine at a constant rate, and it is cleared from the body by the kidneys.

Arginine is considered a semi-essential amino acid because even though the body normally makes enough of it, supplementation is sometimes needed. For example, people with protein malnutrition, excessive ammonia production, excessive lysine intake, burns, infections, peritoneal dialysis, rapid growth, urea synthesis disorders, or sepsis may not have enough arginine. Symptoms of arginine deficiency include poor wound healing, hair loss, skin rash, constipation, and fatty liver.

Arginine changes into nitric oxide, which causes blood vessel relaxation (vasodilation). Early evidence suggests that arginine may help treat medical conditions that improve with vasodilation, such as chest pain, clogged arteries (called atherosclerosis), coronary artery disease, erectile dysfunction, heart failure, intermittent claudication/peripheral vascular disease, and blood vessel swelling that causes headaches (vascular headaches). Arginine also triggers the body to make protein and has been studied for wound healing, bodybuilding, enhancement of sperm production (spermatogenesis), and prevention of wasting in people with critical illnesses.

Arginine hydrochloride has a high chloride content and has been used to treat metabolic alkalosis.

What is L-Arginine?
An essential amino acid that plays an important role in cell division, the healing of wounds, removing ammonia from the body, immune function, and the release of hormones.

Where it is found
Animal sources
Beef, pork (bacon, ham), dairy products, chicken, turkey and seafood are significant sources of L-arginine. These animal proteins can also be high in fat, which is not ideal for a healthy diet. And meats are higher in L-lysine content, which is an amino acid that utilizes the same metabolic pathway as L-arginine. The intake of one amino-acid can decrease the effects of the other. This should be considered when you are trying to increase the amount of L-arginine in the body.

Vegetable sources
Plant proteins contain larger amounts of L-arginine than animal sources. Almonds, Brazil nuts, pecans, cashews, hazelnuts, walnuts, buckwheat, wheat germ, wheat flour, seeds (sesame, sunflower, pumpkin), raisins, brown rice, oats, granola, chickpeas and coconut are all excellent sources of L-arginine.

Possible Side effects / Precautions / Possible Interactions:
L-arginine is POSSIBLY SAFE for most people when taken appropriately by mouth short-term. It can cause some side effects such as abdominal pain, bloating, diarrhea, gout, blood abnormalities, allergies, airway inflammation, worsening of asthma, and low blood pressure.

Special Precautions & Warnings:
Pregnancy and breast-feeding: L-arginine is POSSIBLY SAFE when used appropriately short-term in pregnancy. Not enough is known about using L-arginine long-term in pregnancy or during breast-feeding. Stay on the safe side and avoid use.

Children: L-arginine is POSSIBLY SAFE when used by mouth in premature infants in appropriate doses. When used in high doses, L-arginine is POSSIBLY UNSAFE. Doses that are too high can cause serious side effects including death in children.

Allergies or asthma: L-arginine can cause an allergic response or make swelling in the airways worse. If you decide to take L-arginine, use it with caution.

Herpes: There is a concern that L-arginine might make herpes worse. There is some evidence that L-arginine is needed for the herpes virus to multiply.

Low blood pressure: L-arginine might lower blood pressure. This could be a problem if you already have low blood pressure.

Recent heart attack: There is a concern that L-arginine might increase the risk of death after a heart attack, especially in older people. If you have had a heart attack recently, don’t take L-arginine.

Surgery: L-arginine might affect blood pressure. There is a concern that it might interfere with blood pressure control during and after surgery. Stop taking L-arginine at least 2 weeks before a scheduled surgery.

Research studies / References