What is L-arginine

Arginine is an semi-essential or conditionally essential amino acid that is physiologically active in the L-form (L-arginine). Arginine is an essential amino acid in infants, because infants are unable to effectively synthesize arginine, making it nutritionally essential for infants, so infants must get arginine from their diet (see Table 1 below). However adults are able to synthesize arginine in the urea cycle. L-arginine is an amino acid that is obtained from the diet and is necessary for the body to make proteins. Arginine is found in plant and animal proteins, such as dairy products, meat, poultry, fish, and nuts. The ratio of L-arginine to lysine is also important: soy and other plant proteins have more L-arginine than animal sources of protein. L-arginine can also be made in a laboratory and used as medicine.

What does L-arginine do?

L-Arginine is an amino acid that has numerous functions in the body. L-Arginine helps dispose of ammonia, is used to make compounds such as nitric oxide (NO), creatine, L-glutamate, and L-proline, and it can be converted into glucose and glycogen if needed ¹⁾. L-arginine is converted in the body into a chemical called nitric oxide (NO). Endothelial nitric oxide synthase (eNOS) stability plays a crucial role in regulating nitric oxide (NO) bioavailability and endothelial function. Endothelial nitric oxide (NO) is synthesized from its substrate L‐arginine, primarily by endothelial nitric oxide synthase (eNOS) and facilitated by the co‐factor tetrahydrobiopterin (BH₄) ²⁾. Endothelial nitric oxide synthase (eNOS) can become unstable and uncoupled if there are deficiencies in L‐arginine and/or any of its cofactors (e.g., tetrahydrobiopterin BH₄), resulting in an increased production of superoxide instead of nitric oxide and impaired endothelial function ³⁾. Nitric oxide (NO) causes blood vessels to open wider for improved blood flow and for treating angina (chest pain) and other cardiovascular problems. Arginine may prevent or treat heart and circulatory diseases, combat fatigue, and stimulate the immune system. L-arginine also stimulates the release of growth hormone, insulin, and other substances in the body. Arginine is also an important intermediate in the urea cycle and in detoxification of nitrogenous wastes.

In large doses, L-arginine also stimulates the release of the hormones growth hormone and prolactin. Arginine is a known inducer of mTOR (mammalian target of rapamycin) and is responsible for inducing protein synthesis through the mTOR pathway. mTOR inhibition by rapamycin partially reduces arginine-induced protein synthesis ⁴⁾. Catabolic disease states such as sepsis, injury, and cancer cause an increase in arginine utilization, which can exceed normal body production, leading to arginine depletion. Arginine also activates AMP kinase (AMPK) which then stimulates skeletal muscle fatty acid oxidation and muscle glucose uptake, thereby increasing insulin secretion by pancreatic beta-cells ⁵⁾.

L‐arginine metabolism is complex and highly regulated. In addition to producing nitric oxide (NO) via endothelial nitric oxide synthase (eNOS), L‐arginine is metabolized by arginase to generate ornithine and urea. Because L‐arginine is a substrate for both endothelial nitric oxide synthase (eNOS) and arginase, high arginase activity may limit L‐arginine availability for eNOS ⁶⁾. L‐arginine can also be methylated to produce asymmetric dimethylarginine (ADMA), N^G‐N^′G‐dimethyl‐l‐arginine (SDMA) and N^G‐mono‐methyl‐ւ‐arginine (L‐NMMA) ⁷⁾. ADMA and L‐NMMA can compete with L‐arginine for eNOS, whereas all three methylarginines can interfere with L‐arginine transport into endothelial cells, resulting in a relative L‐arginine deficiency ⁸⁾. Thus, increased metabolism of L‐arginine via the urea cycle and/or methylation could result in reduced L‐arginine bioavailability, eNOS uncoupling and reduced nitric oxide biosynthesis.

L-arginine is used for heart and blood vessel conditions including congestive heart failure, chest pain (angina), high blood pressure, high cholesterol, heart surgery, recovery after heart transplant, heart attack, and coronary artery disease. L-arginine is also used for recurrent pain in the legs due to blocked arteries (intermittent claudication), decreased mental capacity in the elderly (senile dementia), erectile dysfunction (ED), altitude sickness, nitrate tolerance, diabetes, diabetic nerve pain, kidney toxicity from cyclosporine, kidney disease, tuberculosis, critical illness, head and neck cancer, obesity, ovary disease (polycystic ovary syndrome), pressure ulcers, respiratory infections, sickle cell disease, stress, and male infertility.

Some people use L-arginine for preventing the common cold, improving kidney function after a kidney transplant, high blood pressure during pregnancy (pre-eclampsia), improving athletic performance, boosting the immune system, and preventing inflammation and tissue death of the digestive tract in premature infants (necrotizing enterocolitis) and preventing slowing of growth of the baby within the uterus.

L-arginine is used in combination with a number of over-the-counter and prescription medications for various conditions. For example, L-arginine is used along with ibuprofen for migraine headaches; with conventional chemotherapy drugs for treating breast cancer; with other amino acids for treating weight loss in people with AIDS; and with fish oil and other supplements for reducing infections, improving wound healing, and shortening recovery time after surgery.

Some people apply L-arginine to the skin to speed wound healing, healing of small rips of the anus, and for increasing blood flow to cold hands and feet, especially in people with diabetes. It is also used as a cream for sexual problems in both men and women. Arginine has also been used for dental caries and dental hypersensitivity.

Data from an uncontrolled open-label study conducted over a 25 year period supports the use of intravenous arginine (in combination with sodium benzoate, sodium phenylacetate and adequate caloric provision) for the treatment of acute hyperammonemia associated with urea-cycle disorders resulting in increased survival. Clinical experience also suggests the utility of intravenous arginine for the management of this condition. Based on the National Organization for Rare Disorders ⁹⁾, the use of arginine (in combination with sodium benzoate, sodium phenylacetate and adequate caloric provision) is effective and recommended for the management of patients with urea-cycle disorders.

Finally, arginine has been injected into the vein for recurrent pain in the legs due to blocked arteries (intermittent claudication), reduced blood flow to the limbs (peripheral artery disease), for detecting growth hormone deficiency, disease due to defective mitochondria (mitochondrial encephalomyopathies), chest pain due to gastric problems, re-stenosis, kidney transplant, nutrition for the critically ill, metabolic acidosis, and increased blood pressure in the artery of the lungs (pulmonary hypertension) in newborns.

L-arginine foods

Table 1. L-arginine rich foods (ordered from highest to low)

Description	Arginine (g) Value Per 100 gram
Seeds, sesame flour, low-fat	7.44
Seeds, cottonseed flour, low fat (glandless)	6.73
Soy protein isolate	6.67
Soy protein isolate, potassium type	6.67
Seeds, cottonseed meal, partially defatted (glandless)	6.63
Gelatins, dry powder, unsweetened	6.62
Peanut flour, defatted	6.24
Seeds, sesame flour, partially defatted	5.98
Seeds, cottonseed flour, partially defatted (glandless)	5.53
Seeds, pumpkin and squash seed kernels, dried	5.35
Seeds, pumpkin and squash seed kernels, roasted, without salt	5.28
Seeds, pumpkin and squash seed kernels, roasted, with salt added	5.28
Seeds, sunflower seed flour, partially defatted	5.07
Mollusks, whelk, unspecified, cooked, moist heat	4.94
Seeds, watermelon seed kernels, dried	4.9
Egg, white, dried, stabilized, glucose reduced	4.89
Nuts, butternuts, dried	4.86
Snacks, pork skins, plain	4.84
Egg, white, dried, powder, stabilized, glucose reduced	4.81
Gelatin desserts, dry mix, reduced calorie, with aspartame, added phosphorus, potassium, sodium, vitamin C	4.78
Gelatin desserts, dry mix, reduced calorie, with aspartame, no added sodium	4.78
Soy protein concentrate, produced by alcohol extraction	4.64
Soy protein concentrate, produced by acid wash	4.64
Seeds, sesame flour, high-fat	4.57
Seeds, hemp seed, hulled	4.55
Snacks, pork skins, barbecue-flavor	4.55
Egg, white, dried, flakes, stabilized, glucose reduced	4.49
Egg, white, dried	4.41
Seeds, cottonseed kernels, roasted (glandless)	4.4
Beverages, Protein powder soy based	4.27
Seaweed, spirulina, dried	4.15
Peanut flour, low fat	4.04
Lupins, mature seeds, raw	3.88
Seeds, safflower seed meal, partially defatted	3.85
Whale, beluga, meat, dried (Alaska Native)	3.84
Fish, cod, Atlantic, dried and salted	3.76
Soy flour, defatted	3.65
Nuts, walnuts, black, dried	3.62
Soy meal, defatted, raw	3.49
Spices, garlic powder	3.37
Peanuts, spanish, oil-roasted, with salt	3.35
Peanuts, spanish, oil-roasted, without salt	3.35
Seeds, sesame seed kernels, dried (decorticated)	3.25
Peanuts, all types, oil-roasted, with salt	3.25
Peanuts, all types, oil-roasted, without salt	3.25
Peanuts, valencia, oil-roasted, with salt	3.23
Peanuts, valencia, oil-roasted, without salt	3.23
Tofu, dried-frozen (koyadofu)	3.19
Tofu, dried-frozen (koyadofu), prepared with calcium sulfate	3.19
Soybeans, mature seeds, raw	3.15
Peanuts, spanish, raw	3.13
Meat extender	3.12
Peanuts, virginia, oil-roasted, with salt	3.09
Peanuts, virginia, oil-roasted, without salt	3.09
Peanuts, all types, raw	3.08
Egg, whole, dried, stabilized, glucose reduced	3.08
Egg, whole, dried	3.07
Soybeans, mature seeds, dry roasted	3.07
Seeds, pumpkin and squash seeds, whole, roasted, without salt	3.05
Seeds, pumpkin and squash seeds, whole, roasted, with salt added	3.05
Peanuts, virginia, raw	3.01
Peanuts, valencia, raw	3
Nuts, mixed nuts, oil roasted, with peanuts, without salt added	2.96
Nuts, mixed nuts, oil roasted, with peanuts, with salt added	2.96
Nuts, mixed nuts, oil roasted, with peanuts, lightly salted	2.96
Peanuts, all types, dry-roasted, with salt	2.83
Peanuts, all types, dry-roasted, without salt	2.83
Peanut butter, smooth style, with salt (Includes foods for USDA’s Food Distribution Program)	2.77
Peanut butter, smooth style, without salt	2.77
Peanut Butter, smooth (Includes foods for USDA’s Food Distribution Program)	2.73
Soybeans, mature seeds, roasted, salted	2.73
Soybeans, mature seeds, roasted, no salt added	2.73
Peanut butter, chunk style, with salt	2.73
Peanut butter, chunk style, without salt	2.73
Soy flour, full-fat, roasted	2.7
Seeds, sesame butter, paste	2.68
Soy flour, full-fat, raw	2.68
Seeds, sesame butter, tahini, from unroasted kernels (non-chemically removed seed coat)	2.66
Seeds, sesame butter, tahini, from raw and stone ground kernels	2.64
Seeds, sesame seeds, whole, dried	2.63
Seeds, sesame butter, tahini, from roasted and toasted kernels (most common type)	2.52
Seeds, sesame seeds, whole, roasted and toasted	2.52
Seeds, sesame seed kernels, toasted, without salt added (decorticated)	2.52
Seeds, sesame meal, partially defatted	2.52
Seeds, sesame seed kernels, toasted, with salt added (decorticated)	2.52
Pork, cured, bacon, cooked, microwaved	2.51
Beef, round, top round roast, boneless, separable lean only, trimmed to 0″ fat, select, cooked, roasted	2.51
Beef, round, eye of round roast, boneless, separable lean only, trimmed to 0″ fat, select, cooked, roasted	2.49
Nuts, almonds, blanched	2.48
Beef, loin, top sirloin filet, boneless, separable lean only, trimmed to 0″ fat, select, cooked, grilled	2.47
Mollusks, whelk, unspecified, raw	2.47
Spices, fenugreek seed	2.46
Nuts, almonds	2.46
Nuts, almonds, oil roasted, without salt added	2.46
Nuts, almonds, oil roasted, with salt added	2.46
Nuts, almonds, oil roasted, lightly salted	2.46
Beef, plate steak, boneless, inside skirt, separable lean only, trimmed to 0″ fat, select, cooked, grilled	2.46
Nuts, almonds, dry roasted, without salt added	2.44
Nuts, almonds, dry roasted, with salt added	2.44
Nuts, pine nuts, dried	2.41
Broadbeans (fava beans), mature seeds, raw	2.41
Seeds, sunflower seed kernels, dried	2.4
Beef, round, top round steak, boneless, separable lean only, trimmed to 0″ fat, all grades, cooked, grilled	2.4
Pork, cured, bacon, cooked, broiled, pan-fried or roasted, reduced sodium	2.4
Beef, top loin filet, boneless, separable lean only, trimmed to 1/8″ fat, select, cooked, grilled	2.4
Nuts, almond butter, plain, without salt added	2.38
Nuts, almond butter, plain, with salt added	2.38
Beef, loin, top loin steak, boneless, lip-on, separable lean only, trimmed to 1/8″ fat, select, cooked, grilled	2.38
Beef, loin, top loin steak, boneless, lip off, separable lean only, trimmed to 0″ fat, select, cooked, grilled	2.38
Mollusks, cuttlefish, mixed species, cooked, moist heat	2.37
Beef, round, eye of round steak, boneless, separable lean only, trimmed to 0″ fat, select, cooked, grilled	2.37
Nuts, mixed nuts, dry roasted, with peanuts, without salt added	2.36
Beef, loin, top sirloin petite roast, boneless, separable lean only, trimmed to 0″ fat, select, cooked, roasted	2.36
Beef, rib, back ribs, bone-in, separable lean only, trimmed to 0″ fat, select, cooked, braised	2.35
Cereals ready-to-eat, wheat germ, toasted, plain	2.35
Egg, yolk, dried	2.34
Beef, rib eye steak, boneless, lip-on, separable lean only, trimmed to 1/8″ fat, select, cooked, grilled	2.33
Beef, rib eye steak, boneless, lip off, separable lean only, trimmed to 0″ fat, select, cooked, grilled	2.33
Beef, round, top round steak, boneless, separable lean only, trimmed to 0″ fat, choice, cooked, grilled	2.32
Pork, cured, bacon, cooked, baked	2.31
Beef, rib eye roast, boneless, lip-on, separable lean only, trimmed to 1/8″ fat, select, cooked, roasted	2.31
Beef, round, top round, separable lean and fat, trimmed to 0″ fat, all grades, cooked, braised	2.3
Crustaceans, spiny lobster, mixed species, cooked, moist heat	2.3
Game meat, bison, chuck, shoulder clod, separable lean only, cooked, braised	2.3
Beef, plate steak, boneless, outside skirt, separable lean only, trimmed to 0″ fat, select, cooked, grilled	2.3
Turkey, ground, fat free, pan-broiled crumbles	2.3
Beef, top loin petite roast, boneless, separable lean only, trimmed to 1/8″ fat, select, cooked, roasted	2.29
Beef, round, top round, separable lean only, trimmed to 0″ fat, choice, cooked, braised	2.28
Beef, round, top round, separable lean only, trimmed to 0″ fat, select, cooked, braised	2.28
Nuts, walnuts, english	2.28
Beef, ribeye petite roast, boneless, separable lean only, trimmed to 0″ fat, select, cooked, roasted	2.28
Beef, round, top round roast, boneless, separable lean only, trimmed to 0″ fat, all grades, cooked, roasted	2.28
Beef, loin, top sirloin cap steak, boneless, separable lean only, trimmed to 1/8″ fat, select, cooked, grilled	2.28
Beef, New Zealand, imported, brisket point end, separable lean only, cooked, braised	2.27
Beef, round, top round steak, boneless, separable lean and fat, trimmed to 0″ fat, select, cooked, grilled	2.27
Beef, round, bottom round, steak, separable lean only, trimmed to 0″ fat, select, cooked, braised	2.26
Formulated bar, MARS SNACKFOOD US, SNICKERS MARATHON Protein Performance Bar, Caramel Nut Rush	2.26
Beef, chuck, mock tender steak, boneless, separable lean only, trimmed to 0″ fat, choice, cooked, braised	2.26
Beef, round, eye of round roast, boneless, separable lean only, trimmed to 0″ fat, all grades, cooked, roasted	2.25
Beef, loin, tenderloin steak, boneless, separable lean only, trimmed to 0″ fat, select, cooked, grilled	2.25
Nuts, pine nuts, pinyon, dried	2.25
Beef, round, top round, separable lean and fat, trimmed to 0″ fat, choice, cooked, braised	2.25
Beef, round, top round, separable lean and fat, trimmed to 0″ fat, select, cooked, braised	2.25
Crustaceans, shrimp, mixed species, cooked, moist heat (may contain additives to retain moisture)	2.25
Beef, chuck, arm pot roast, separable lean only, trimmed to 1/8″ fat, choice, cooked, braised	2.25
Beef, rib eye steak, bone-in, lip-on, separable lean only, trimmed to 1/8″ fat, select, cooked, grilled	2.24
Lamb, New Zealand, imported, fore-shank, separable lean only, cooked, braised	2.24
Nuts, mixed nuts, dry roasted, with peanuts, with salt added	2.24
Beef, loin, top sirloin filet, boneless, separable lean only, trimmed to 0″ fat, all grades, cooked, grilled	2.24
Beef, chuck, arm pot roast, separable lean only, trimmed to 1/8″ fat, all grades, cooked, braised	2.24

[Source ¹⁰⁾]

What is L-arginine good for

L-arginine possibly effective for:

• Chest pain (angina). Taking L-arginine seems to decrease symptoms and improve exercise tolerance and quality of life in people with angina. However, L-arginine does not seem to help widen the blood vessels that are narrowed in angina.
• Erectile dysfunction (ED). Taking 5 grams of L-arginine by mouth daily seems to improve sexual function in men with ED. Taking lower doses might not be effective. However, there is some early evidence that taking L-arginine with maritime pine bark extract and other ingredients, might improve the effectiveness of low-dose L-arginine for ED.
• High blood pressure. There is early evidence that taking L-arginine by mouth can reduce blood pressure in healthy people, people with high blood pressure, and people with slightly high blood pressure with or without diabetes.
• Inflammation and tissue death in the digestive tract in premature infants (necrotizing enterocolitis). Adding L-arginine to formula seems to prevent inflammation of the digestive tract in premature infants. A total of 5 premature infants need to receive arginine to prevent one instance of digestive tract inflammation.
• Nitrate tolerance. Taking L-arginine by mouth seems to prevent nitrate tolerance in people taking nitroglycerin for chest pain (angina pectoris).
• Leg pain associated with poor blood flow (peripheral arterial disease). Research suggests that taking L-arginine by mouth or intravenously (by IV) for up to 8 weeks increases blood flow in people with peripheral arterial disease. However, long-term use (up to 6 months) does not improve walking speed or distance in people with peripheral arterial disease.
• Improving recovery after surgery. Taking L-arginine with ribonucleic acid (RNA) and eicosapentaenoic acid (EPA) before surgery or afterwards seems to help reduce the recovery time, reduce the number of infections, and improve wound healing after surgery.
• High blood pressure during pregnancy (pre-eclampsia). Most research shows that L-arginine can reduce blood pressure in women with this condition. L-arginine might also prevent this condition in pregnant women.

L-arginine possibly ineffective for:

• Kidney disease. Most early research suggests that taking L-arginine by mouth or intravenously (by IV) does not improve kidney function in most people with kidney failure or kidney disease. However, taking L-arginine by mouth might improve kidney function and reverse anemia in elderly people with kidney disease-associated anemia.
• Heart attack. Taking L-arginine does not seem to help prevent a heart attack. It also does not seem to be beneficial for treating a heart attack after it has occurs. In fact, there is concern that L-arginine might be harmful for people after a recent heart attack. Do not take L-arginine if you have had a recent heart attack.
• Tuberculosis. Adding arginine to standard treatment for tuberculosis does not seem to help improve symptoms or clear the infection.
• Wound healing. Taking L-arginine does not seem to improve wound healing.

Insufficient evidence to rate effectiveness for:

• AIDS-related wasting. Taking L-arginine by mouth, along with hydroxymethylbutyrate (HMB) and glutamine, for 8 weeks seems to increase body weight and improve immune function in people with HIV/AIDS. However, taking L-arginine by mouth, along with omega-3 fatty acids and a balanced nutritional supplement, for 6 months does not improve body weight or fat mass, energy intake, or immune function in people who are HIV-positive.
• Altitude sickness. Early research suggests that L-arginine does not reduce altitude sickness.
• Anal fissures. There is inconsistent evidence about that effects of L-arginine for treating anal fissures. Applying a topical gel containing L-arginine for at least 12 weeks might heal anal fissures in people who do not respond to traditional care. However, applying L-arginine to the skin does not seem to be better than surgery for anal fissures.
• Breast cancer. Early research shows that taking L-arginine before chemotherapy does not improve the response rate in people with breast cancer.
• Heart failure. Taking L-arginine by mouth, together with conventional treatment, seems to improve kidney function in people with heart failure. However, it might not improve the ability to exercise, quality of life, or blood circulation. L-arginine should not be used in place of conventional treatment.
• Coronary artery bypass graft (CABG) surgery. There is mixed evidence about the effects of L-arginine in protecting the heart during CABG. Some research suggests that giving L-arginine intravenously (by IV) may be helpful in people undergoing CABG. Other research shows that it does not help.
• Clogged blood vessels (coronary artery disease). Early research suggests that taking L-arginine intravenously (by IV) before exercising can improve blood vessel function in people with coronary artery disease. However, it does not improve blood flow to the heart.
• Critical illness (trauma). Research shows that taking L-arginine by mouth with glutamine, nucleotides, and omega-3 fatty acids reduces the recovery time, the need for help with breathing, and risk of infections in people who are critically ill. However, it does not reduce the risk of death.
• Memory loss (dementia). Early research suggests that L-arginine might improve memory loss related to aging.
• Cavities. Early research suggests that using a sugarless mint containing an arginine complex (CaviStat) for one year reduces the number of cavities in molars of children compared with sugarless mints that do not contain arginine.
• Sensitive teeth. Early research suggests that using a toothpaste containing arginine, calcium, and fluoride reduces tooth sensitivity when used twice daily.
• Diabetes. Taking L-arginine by mouth seems to improve blood sugar control in people with existing diabetes. However, it is unclear if arginine helps prevent people with pre-diabetes from developing diabetes.
• Diabetic foot ulcers. Early research shows that applying L-arginine to the feet daily can improve circulation in people with diabetes, which might be helpful in preventing diabetic foot ulcers. However, if there is already an ulcer on the foot, injecting L-arginine under the skin near the ulcer does not seem to shorten healing time or lower the chance of needing an amputation in the future.
• Nerve damage due to diabetes. Early research suggests that taking L-arginine daily for 3 months does not improve nerve damage related to diabetes.
• Muscle problems in the esophagus. Early research suggests that taking L-arginine by mouth or as an infusion can reduces the number and intensity of chest pain attacks in people with chest pain that is not related to the heart.
• Exercise performance. There is inconsistent evidence about the effects of L-arginine on exercise performance. Some evidence shows that taking 6 grams of L-arginine in a drink increases exercise time until becoming tired. Also taking arginine with grape seed extract appears to improve working ability in men and decreases their tiredness. However, taking arginine 6 grams once does not affect strength during exercise.
• Head and neck cancer. Supplementing a feeding tube with L-arginine does not seem to improve immune function, reduce tumor size, or improve healing in people with head and neck cancer.
• Heart transplant. Early research suggests that taking L-arginine by mouth for 6 weeks increases walking distance and improves breathing in people with a heart transplant.
• Infertility. There is inconsistent evidence about the effectiveness of L-arginine for infertility. Some early research suggests that taking 16 grams of L-arginine daily increases egg counts collected in women undergoing IVF. However, it does not seem to improve pregnancy rates. Other research suggests that taking L-arginine does not improve semen quality in men with unexplained infertility.
• Bladder inflammation. Taking L-arginine by mouth seems to reduce pain and some symptoms of bladder inflammation, although improvements may take 3 months to occur. However, L-arginine does not seem to reduce the need to urinate at night or improve the frequency of urination.
• Poor growth of fetus during pregnancy. Early research suggests that taking L-arginine during pregnancy can increase the birthweight of babies who show poor growth while still in their mother’s womb. However, L-arginine does not seem to increase birthweight or reduce the risk of the baby dying if the baby has extremely poor growth while in the womb.
• Mitochondrial encephalomyopathies (a group of disorders that lead to muscle and nervous system problems). There is some interest in using L-arginine to improve symptoms associated with MELAS (myoclonic epilepsy with lactic acidosis and stroke-like episodes) syndrome. Early research suggests that administering L-arginine intravenously (by IV) within one hour of stroke-like symptoms improves headaches, nausea, vomiting, blindness, and the appearance of bright spots in people with this condition.
• Migraine headache. Taking L-arginine by mouth along with the painkiller ibuprofen seems to be effective for treating migraine headache. This combination sometimes starts to work within 30 minutes. However, it is hard to know how much of the pain relief is due to L-arginine, since ibuprofen can relieve migraine pain on its own.
• Obesity. Early research suggests that taking a specific arginine supplement (NOW Foods, Bloomingdale, IL) 3 grams three times daily may decrease waist size and weight in women.
• Ovarian disease (polycystic ovarian syndrome). Early research suggests that taking N-acetyl-cysteine and L-arginine daily for 6 months can improve menstrual function and reduces insulin resistance in people with polycystic ovarian syndrome.
• Pressure ulcers. Taking L-arginine by mouth along with the painkiller ibuprofen seems to be effective for treating migraine headache. This combination sometimes starts to work within 30 minutes. However, it is hard to know how much of the pain relief is due to L-arginine, since ibuprofen can relieve migraine pain on its own.
• Restricted blood flow (restenosis). Some research suggests that giving L-arginine during stent implantation followed by L-arginine supplementation by mouth for 2 weeks after stent implantation does not reduce the risk of restricted blood flow. However, other evidence suggests that administering L-arginine at the site of stent implantation may reduce artery wall thickening.
• Kidney transplant. There is conflicting evidence about the effects of L-arginine for people with kidney transplants. It is unclear if it helps.
• Respiratory infections. Early research suggests that taking L-arginine by mouth for 60 days prevents the recurrence of respiratory infections in children.
• Sickle-cell disease. Early research suggests that taking L-arginine for 5 days might be useful for people with sickle cell disease who have high blood pressure in the lungs.
• Stress. Some early research suggests that taking a combination of L-lysine and L-arginine for up to 10 days reduces stress and anxiety in healthy people and those prone to stress.
• Prevention of the common cold.
• Female sexual problems.

More evidence is needed to rate the effectiveness of L-arginine for these uses.

L-arginine dosage

The following doses have been studied in scientific research:

By mouth:

• For chest pain associated with coronary artery disease (angina pectoris): 3-6 grams three times per day for up to one month.
• For preventing the loss of the effectiveness of nitroglycerin in relieving pain in people with chest pain due to coronary artery disease (angina pectoris): 700 mg four times daily.
• For organic erectile dysfunction (ED): 5 grams per day. Taking lower doses might not be effective.
• For high blood pressure: 4-24 grams per day for 2-24 weeks.
• For preventing inflammation of the digestive tract in premature infants: 261 mg/kg added to oral feedings daily for the first 28 days of life.
• For reducing pain when walking in people with a disease called peripheral arterial disease: 6 grams for up to 8 weeks.
• For preventing high blood pressure during pregnancy: 3 grams daily for 3 weeks. Two bars of a medical food (Heart Bars) with arginine 6.6 grams and antioxidant vitamins daily starting at 14-32 weeks gestation and continuing until delivery. 4 grams arginine (Bioarginina, Damor, Italy) daily for 10-12 weeks.

By IV (intravenously):

• For reducing pain when walking in people with a disease called peripheral arterial disease: 6 grams for up to 8 weeks.

L-arginine supplement side effects

L-arginine is POSSIBLY SAFE for most people when taken appropriately by mouth, administered as a shot, or applied to the skin, 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.

Check with your doctor or nurse immediately if any of the following side effects occur while taking arginine:

Rare side effects

• redness or discoloration of the skin
• swelling of the hands and face

Incidence Not Known

• blood in the urine
• cough
• difficulty swallowing
• dizziness
• fast heartbeat
• hives, itching, skin rash
• pain or redness at the injection site
• pale skin at the injection site
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• tightness in the chest
• unusual tiredness or weakness

Get emergency help immediately if any of the following symptoms of overdose occur while taking arginine:

Symptoms of L-arginine overdose

• confusion
• deep or fast breathing with dizziness
• drowsiness
• muscle tremors
• numbness of the feet, hands, and around the mouth
• rapid, deep breathing
• restlessness
• stomach cramps

Some side effects of arginine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common side effects

• bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, rash, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
• headache
• nausea
• numbness
• vomiting

Special precautions and warnings

Pregnancy and breast-feeding: L-arginine is POSSIBLY SAFE when taken by mouth appropriately for a short-term during 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. However, L-arginine is POSSIBLY UNSAFE when used in high doses. 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 are prone to allergies or asthma and decide to take L-arginine, use it with caution.

Cirrhosis: L-arginine should be used with caution in people with cirrhosis.

Guanidinoacetate methyltransferase deficiency: People with this inherited condition are unable to convert arginine and other similar chemicals into creatine. To prevent complications associated with this condition, these people should not take arginine.

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.

Kidney disease: L-arginine has caused high potassium levels when used by people with kidney disease. In some cases, this has resulted in a potentially life-threatening irregular heartbeat.

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.

L-arginine interactions with medications

Major interactions

Do NOT take this combination.

Medications for high blood pressure (Antihypertensive drugs)

• L-arginine seems to decrease blood pressure. Taking L-arginine along with medications for high blood pressure might cause your blood pressure to go too low.
• Some medications for high blood pressure include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), amlodipine (Norvasc), hydrochlorothiazide (HydroDIURIL), furosemide (Lasix), and many others.

Moderate interactions

Be cautious with this combination.

Medications for diabetes (Antidiabetes drugs)

• L-arginine seems to decrease blood sugar in people with type 2 diabetes. Diabetes medications are also used to lower blood sugar. Taking L-arginine along with diabetes medications might cause your blood sugar to go too low. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.
• Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.

Medications for high blood pressure (ACE inhibitors)

• L-arginine seems to decrease blood pressure. Taking L-arginine along with certain medications for high blood pressure, called ACE inhibitors might cause your blood pressure to go too low. Also, ACE inhibitors can increase potassium levels. L-arginine may also increase potassium levels. Taking L-arginine with ACE inhibitors might cause potassium levels to become too high.
• Some ACE inhibitors include benazepril (Lotensin), captopril (Capoten), enalapril (Vasotec), fosinopril (Monopril), lisinopril (Prinivil, Zestril), moexipril (Univasc), perindopril (Aceon), quinapril (Accupril), ramipril (Altace), and trandolapril (Mavik).

Medications for high blood pressure [Angiotensin receptor blockers (ARBs)]

• L-arginine seems to decrease blood pressure. Taking L-arginine along with medications for high blood pressure might cause your blood pressure to go too low.
• The ARBs include losartan (Cozaar), valsartan (Diovan), irbesartan (Avapro), candesartan (Atacand), telmisartan (Micardis), and eprosartan (Teveten).

Medications for high blood pressure (Isoproterenol)

• L-arginine seems to decrease blood pressure. Isoproterenol is a drug that is used to lower blood pressure. Taking L-arginine along with isoproterenol might cause your blood pressure to go too low.

Medications that increase blood flow to the heart (Nitrates)

• L-arginine increases blood flow. Taking L-arginine with medications that increase blood flow to the heart might increase the chance of dizziness and lightheadedness.
• Some of these medications that increase blood flow to the heart include nitroglycerin (Nitro-Bid, Nitro-Dur, Nitrostat), and isosorbide (Imdur, Isordil, Sorbitrate).

Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)

• L-arginine seems to slow blood clotting. Taking L-arginine along with medications that also slow clotting might increase the chances of bruising and bleeding.
• Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, ticlopidine (Ticlid), warfarin (Coumadin), and others.

Sildenafil (Viagra)

• Sildenafil (Viagra) can lower blood pressure. L-arginine can also lower blood pressure. Taking sildenafil (Viagra) and L-arginine together might cause the blood pressure to go too low. Blood pressure that is too low can cause dizziness and other side effects.

Water pills (Potassium-sparing diuretics)

• L-arginine might increase potassium levels in the body. Some “water pills” might also increase potassium in the body. In theory, taking L-arginine along with some “water pills” might cause too much potassium to be in the body. Some water pills include amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium).

Some “water pills” that increase potassium in the body include spironolactone (Aldactone), triamterene (Dyrenium), and amiloride (Midamor).

Interactions with herbs and supplements

Herbs and supplements that might lower blood pressure

• L-arginine seems to lower blood pressure. Using it along with other herbs and supplements that have this same effect might increase the risk of blood pressure dropping too low in some people. Some of these products include andrographis, casein peptides, cat’s claw, coenzyme Q-10, fish oil, L-arginine, lycium, stinging nettle, theanine, and others.

Herbs and supplements that might lower blood sugar

• L-arginine seems to lower blood sugar. Using it along with other herbs and supplements that have the same effect might cause blood sugar to become too low in some people. Some of these products include devil’s claw, fenugreek, guar gum, Panax ginseng, Siberian ginseng, and others.

Herbs and supplements that might slow blood clotting

• Using L-arginine along with herbs that can slow blood clotting could increase the risk of bleeding in some people. These herbs include angelica, clove, danshen, garlic, ginkgo, Panax ginseng, red clover, turmeric, and others.

Xylitol

• L-arginine can cause an organ in the body called the pancreas to release a hormone called glucagon. Glucagon comes to the rescue when blood sugar levels are too low. Glucagon makes the liver convert stored sugar to useable sugar that is released into the bloodstream. Using L-arginine along with xylitol can keep L-arginine from stimulating the pancreas to release glucagon.