
Common Names
- L-arginine
For Patients & Caregivers
Tell your healthcare providers about any dietary supplements you’re taking, such as herbs, vitamins, minerals, and natural or home remedies. This will help them manage your care and keep you safe.
How It Works
Arginine is made in the body and found in many protein-rich foods. Although it is used in clinical applications, evidence for other uses is lacking and in some instances may increase risk for harm.
Arginine is an amino acid that is produced by the body. Clinical applications include its use during recovery from surgery, for heart and blood vessel conditions like angina or high blood pressure, and for some pregnancy complications. Arginine has also been used to enhance immune function and athletic performance or to improve conditions such as migraines and erectile dysfunction, but more studies are needed.
A few trials of arginine supplementation have been conducted in cancer patients. Some show that arginine-enriched nutritional formulas taken around the time of surgery may improve wound healing, enhance immune status, and reduce length of hospital stay. However, an analysis suggests that arginine supplementation may increase inflammatory biomarkers in certain subgroups, including cancer or older patients. Other studies suggest potential harm with long-term supplementation or in those who have had a heart attack. Therefore, additional studies are needed to determine the circumstances under which arginine supplementation is safe and effective.
Purported uses and benefits
-
To treat angina, hardening of blood vessels, or high blood pressure
Some studies support the benefits of arginine for angina, atherosclerosis, and hypertension, but there are some conditions where supplementation may increase risk for harm. Patients should therefore be managed by their treating physician. -
To speed wound healing
Data on whether arginine can improve wound healing are mixed. -
To improve immune function
Data on whether arginine can improve immune function are mixed. -
To treat erectile dysfunction
Preliminary data suggest arginine may help improve sexual function in men, but more studies are needed. -
To treat migraine headaches
Preliminary data suggest that arginine taken with ibuprofen may increase pain relief in patients with migraines, but more studies are needed.
Patient Warnings
- Patients who have had a heart attack should avoid using arginine, as one study suggests it may increase risk for additional harm.
- Long-term arginine supplementation in patients with peripheral artery disease may be harmful. Patients with this condition should be managed by their treating physician.
- Some evidence suggests an increase in breast tumor growth after taking arginine supplements, but more studies are needed to confirm this.
Do Not Take If
- You are taking medicine for high blood pressure, heart conditions, or erectile dysfunction: Arginine may have additional blood pressure-lowering effects.
- You are a cancer patient: Some data suggest increases in inflammatory biomarkers with supplementation, so patients should use caution and discuss any use of arginine with their treating physician.
- You have had a heart attack: Patients with this condition should use caution and be managed by their treating physician.
- You have peripheral artery disease: Patients with this condition should use caution and be managed by their treating physician.
Side Effects
Special Point
For Healthcare Professionals
Clinical Summary
Arginine is an amino acid that is synthesized in the body. Oral arginine has been used for various conditions such as hypertension, angina, atherosclerosis, migraines, and erectile dysfunction. Its vasodilatory properties are thought responsible for beneficial effects. Arginine has also been used to enhance wound healing, immune function, and athletic performance.
Some studies support the use of arginine in coronary artery and peripheral artery diseases (10) (11) (12) (13), but long-term supplementation worsened PAD (14). In addition, oral supplementation in patients who had an acute myocardial infarction did not improve ejection fraction or vascular stiffness, and may be associated with higher mortality (38). A meta-analysis of arginine supplementation on markers for cardiovascular disease, obesity, or diabetes also did not find benefit, except perhaps in a select group of patients (39). Smaller studies suggest supplementation with arginine, glutamine, and HMB may benefit vascular endothelial function in older adults (33), but arginine supplementation alone did not improve blood flow or muscle performance in older women (34).
In cancer patients, preliminary data are mixed for perioperative enteral arginine-enriched formulas to improve wound healing (1) (41) and immune function (27) (35) (42), but other studies suggest such formulas may reduce complications and length of hospital stay (30) (36). However, early postoperative arginine-enriched feeding had no impact on long-term survival in patients undergoing surgery for oesophagogastric and pancreaticobiliary cancers (48), and a trial of an oral formula containing arginine, HMB, and glutamine to improve cachexia management in newly diagnosed lung cancer patients was halted due to slow accrual and partial adherence (49).
Some data suggest a prophylactic arginine-containing supplement may reduce incidence of hand-foot syndrome in hepatocellular carcinoma patients taking sorafenib (43). Interestingly, arginine deprivation-based treatments are also being pursued as potential cancer treatments (31) (32) (37).
Although a meta-analysis did not find significant effects with arginine supplementation on inflammatory biomarkers, subgroup analysis suggests it may increase circulating C-reactive protein in cancer patients, those older than age 60 or with higher baseline CRP levels, or with use of enteral formulas (44). Additional studies are needed to determine the circumstances under which arginine supplementation could be safe and effective.
Purported uses and benefits
Mechanism of Action
Arginine is unique among amino acids for its vasodilatory properties (11). Arginine acts as a precursor for the synthesis of endogenous NO via the action of nitric oxide synthase. NO functions as a paracrine-signaling molecule mediating vasodilation and inhibition of platelet activation, monocyte and leucocyte adhesion, and smooth muscle cell proliferation. NO also helps to control vascular oxidative stress and redox-regulated gene expression (22). Arginine is also needed for the synthesis of creatine which is important in muscle contraction (22). In colorectal adenoma cells, arginine reduces the expression of survivin, an inhibitor of apoptosis, and induces iNOS expression (23).
Warnings
- In patients who had an acute myocardial infarction, arginine supplementation may increase risk of mortality (38).
- Long-term supplementation may worsen peripheral artery disease (14).
- Limited studies suggest that arginine supplementation may increase breast tumor growth, but more research is needed to examine this (9) (21).
Adverse Reactions
Case reports
Esophagitis: In a 40-year-old woman after ingestion of l-arginine, selenium, and vitamin E supplements. A few other cases have also pointed to arginine as the suggested cause (45).
Acute pancreatitis: Upper abdominal pain and increased serum lipase levels in a young adult man, attributed to a protein shake containing arginine. The condition improved with treatment and cessation of the product (46). Another earlier case in a young adult had also been reported (47).