What is L-Arginine?

L-arginine is an amino acid that is found in red meat, poultry, fish, and dairy products. It can also be made in a laboratory. L-arginine is used for heart and blood vessel conditions including congestive heart failure (CHF), chest pain, high blood pressure, and coronary artery disease. L-arginine is also used for recurrent pain in the legs due to blocked arteries (peripheral arterial disease).

Some people use L-arginine for treating erectile dysfunction and sexual performance problems. It is also used for enhancing exercise performance and building lean muscle mass.

L-arginine is sometimes injected into the vein or taken by mouth for treating leg pain caused by blocked arteries.

How does it work?

L-arginine is a building block for protein. It also becomes nitric oxide (NO) in the body. NO is important for erections because it helps blood vessels relax, so more blood can flow into the penis. L-arginine might help dilate blood vessels and improve blood flow in people with congestive heart failure, chest pain, or high blood pressure. L-arginine has also been studied for treating clogged arteries and improving exercise performance and capacity.

Are there safety concerns?

L-arginine is LIKELY SAFE for most adults when taken by mouth in amounts up to 12 grams daily, short-term. L-arginine has been used safely in doses up to 6 grams daily for up to 3 months. However, some side effects can occur such as bloating, diarrhea, gout, blood abnormalities, allergies, airway inflammation, worsening of asthma, and low blood pressure.

Special Precautions & Warnings:

Pregnancy and breast-feeding: L-arginine appears to be LIKELY SAFE when taken by mouth appropriately. However, not enough is known about the safety of taking L-arginine during pregnancy. L-arginine should be used with caution during breast-feeding because it’s not known if it passes into breast milk.

Children: L-arginine appears to be LIKELY SAFE when taken by mouth appropriately. However, L-arginine is POSSIBLY UNSAFE when injecting large doses into the vein or muscle. Injections of L-arginine can cause death in infants with a genetic disorder called glycogen storage disease type IA.

Kidney problems: L-arginine can make kidney problems worse. If you have kidney disease, don’t use L-arginine supplements.

Allergies: L-arginine can cause an allergic reaction in some people. Symptoms can include wheezing, coughing, and swelling of the face, throat, tongue, and lips. L-arginine should be used with caution in people with a history of allergies or asthma.

Major surgery: L-arginine might interfere with blood pressure control during and after major surgery. Stop taking L-arginine at least 2 weeks before a scheduled surgery.

Effectiveness

Most L-arginine research has been done on heart conditions and erectile dysfunction. L-arginine does not seem to help people with heart failure live any longer. L-arginine might help improve symptoms of heart failure, but more research is needed to know for sure. L-arginine seems to be helpful for treating erectile dysfunction but only in men who have low levels of L-arginine. L-arginine might not help other men with erectile dysfunction. L-arginine has also been studied for clogged arteries, chest pain, and improving exercise performance and capacity, but there is not enough evidence to know if it works for these conditions.

Dosage

The appropriate dose of L-arginine depends on several factors such as the user’s age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for L-arginine. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

L-arginine is sometimes injected into the vein or taken by mouth for treating leg pain caused by blocked arteries (peripheral arterial disease), heart failure, chest pain, and high blood pressure. L-arginine is also used for treating erectile dysfunction, infertility, and migraine headaches.

Other uses include treatment of congestive heart failure, blocked arteries, high blood pressure, coronary artery disease, and sexual performance problems. It is also sometimes used for increasing exercise tolerance, improving liver function in people with hepatitis, enhancing immune function in people with HIV/AIDS, and preventing the rejection of kidney transplants.

L-arginine is used in combination with ibuprofen for treating a condition called Reiter’s syndrome. L-arginine is also used in combination with pycnogenol for treating clogged arteries, erectile dysfunction, and diabetes.

Some people apply L-arginine to the skin for treating cold sores, wounds, and poor circulation. L-arginine cream is also used for weak muscles (muscular dystrophy), Raynaud’s phenomenon, and a skin condition called vitiligo.a