What is arginine?
Arginine, also called L-arginine, is an amino acid used by the body as a protein building block. It’s also an intermediate metabolite in the urea cycle and the nitric oxide cycle.[1][2][3] The urea cycle removes excess ammonia, a toxic molecule, from the body, and the nitric oxide cycle produces nitric oxide, which is an important signaling molecule involved in vascular function.[1][2][3] Although the body can synthesize arginine, arginine can also be obtained in the diet through protein-containing foods or dietary supplements.[1][2][3]
What are arginine’s main benefits?
Daily supplementation with arginine can reduce blood pressure in people with healthy blood pressure and people with hypertension (high blood pressure).[4] Evidence also supports the use of arginine to help improve birth outcomes in pregnant women who have conditions like hypertension and preeclampsia, or who have a history of poor pregnancy outcomes. The improved outcomes include a reduced risk of small for gestational age infants[5] and a reduced risk of intrauterine growth restriction of the baby.[6] Arginine can also improve maternal outcomes by reducing the risk of preeclampsia in the pregnant mother.[7][8][9] Additionally, arginine can reduce blood triglycerides,[10][11] particularly in people older than 50 or in people with metabolic syndrome or type 2 diabetes.[10]
In men with erectile dysfunction, daily supplementation with arginine can alleviate symptoms.[12] Furthermore, the combination of arginine with phosphodiesterase type 5 inhibitors (PDE5Is), like Viagra, improves sexual function in men with erectile dysfunction more than treatment with PDE5Is alone.[13]
Evidence also shows that daily supplementation with arginine might increase VO2max, but the magnitude of improvement is negligible and unlikely to be clinically meaningful.[14] Furthermore, most studies find no beneficial effect of arginine on exercise performance.[15] It is only when highly-varied types of exercise (aerobic, anaerobic, resistance, etc.) and performance outcomes (time-to-exhaustion, time-trials, sprint time, 1-rep-max, reps-to-failure, etc.) are inappropriately pooled that meta-analyses find a performance benefit from arginine.[15]
What are arginine’s main drawbacks?
Animal studies show that neither oral nor intravenous delivery of arginine causes toxicity, even at high doses.[16][17] However, supplementation with arginine has been reported to cause adverse gastrointestinal effects in humans, including nausea, vomiting, and diarrhea.[18] For this reason, upper-limit guidelines of approximately 20 to 30 grams per day have been proposed for supplemental arginine intake,[19][20] but more long-term safety data in humans are needed to accurately define a tolerable upper intake level.
How does arginine work?
Nitric oxide is a key molecule involved in vasodilation (the relaxation and widening of blood vessels to increase blood flow to tissues that lack oxygen or nutrients).[21][2] The beneficial effects of arginine on high blood pressure[4][7][8] and erectile dysfunction[12][13] are likely related to vasodilation because arginine increases nitric oxide synthesis.[21][2][3]
A similar mechanism may explain how arginine might increase VO2max.[22][23][14] Additionally, nitric oxide might have direct effects on muscle contractile function.[22][24] Furthermore, arginine’s role in the urea cycle helps with the excretion of ammonia[1], the accumulation of which might induce fatigue during exercise.[25][26][27]
What are other names for Arginine
- L-Arginine
Dosage information
The standard preworkout dose for arginine is 3–6 grams.
Taking more than 10 grams of arginine at once can result in gastrointestinal distress and diarrhea, but it is possible to maintain elevated arginine levels throughout the day by taking three spaced doses (15–18 grams/day). However, citrulline supplementation is more effective at maintaining elevated arginine levels for long periods of time.
Examine Database: Arginine
Research FeedRead all studies
In this randomized controlled trial, regularly taking arginine before resistance training did not lead to greater gains in muscle mass and strength compared to resistance training alone. However, multiple issues limit our confidence in the study.
Frequently asked questions
Arginine, also called L-arginine, is an amino acid used by the body as a protein building block. It’s also an intermediate metabolite in the urea cycle and the nitric oxide cycle.[1][2][3] The urea cycle removes excess ammonia, a toxic molecule, from the body, and the nitric oxide cycle produces nitric oxide, which is an important signaling molecule involved in vascular function.[1][2][3] Although the body can synthesize arginine, arginine can also be obtained in the diet through protein-containing foods or dietary supplements.[1][2][3]
Daily supplementation with arginine can reduce blood pressure in people with healthy blood pressure and people with hypertension (high blood pressure).[4] Evidence also supports the use of arginine to help improve birth outcomes in pregnant women who have conditions like hypertension and preeclampsia, or who have a history of poor pregnancy outcomes. The improved outcomes include a reduced risk of small for gestational age infants[5] and a reduced risk of intrauterine growth restriction of the baby.[6] Arginine can also improve maternal outcomes by reducing the risk of preeclampsia in the pregnant mother.[7][8][9] Additionally, arginine can reduce blood triglycerides,[10][11] particularly in people older than 50 or in people with metabolic syndrome or type 2 diabetes.[10]
In men with erectile dysfunction, daily supplementation with arginine can alleviate symptoms.[12] Furthermore, the combination of arginine with phosphodiesterase type 5 inhibitors (PDE5Is), like Viagra, improves sexual function in men with erectile dysfunction more than treatment with PDE5Is alone.[13]
Evidence also shows that daily supplementation with arginine might increase VO2max, but the magnitude of improvement is negligible and unlikely to be clinically meaningful.[14] Furthermore, most studies find no beneficial effect of arginine on exercise performance.[15] It is only when highly-varied types of exercise (aerobic, anaerobic, resistance, etc.) and performance outcomes (time-to-exhaustion, time-trials, sprint time, 1-rep-max, reps-to-failure, etc.) are inappropriately pooled that meta-analyses find a performance benefit from arginine.[15]
Animal studies show that neither oral nor intravenous delivery of arginine causes toxicity, even at high doses.[16][17] However, supplementation with arginine has been reported to cause adverse gastrointestinal effects in humans, including nausea, vomiting, and diarrhea.[18] For this reason, upper-limit guidelines of approximately 20 to 30 grams per day have been proposed for supplemental arginine intake,[19][20] but more long-term safety data in humans are needed to accurately define a tolerable upper intake level.
Nitric oxide is a key molecule involved in vasodilation (the relaxation and widening of blood vessels to increase blood flow to tissues that lack oxygen or nutrients).[21][2] The beneficial effects of arginine on high blood pressure[4][7][8] and erectile dysfunction[12][13] are likely related to vasodilation because arginine increases nitric oxide synthesis.[21][2][3]
A similar mechanism may explain how arginine might increase VO2max.[22][23][14] Additionally, nitric oxide might have direct effects on muscle contractile function.[22][24] Furthermore, arginine’s role in the urea cycle helps with the excretion of ammonia[1], the accumulation of which might induce fatigue during exercise.[25][26][27]
Update History
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Research Breakdown
References
Examine Database References
- Blood glucose - Monti LD, Setola E, Lucotti PC, Marrocco-Trischitta MM, Comola M, Galluccio E, Poggi A, Mammì S, Catapano AL, Comi G, Chiesa R, Bosi E, Piatti PMEffect of a long-term oral l-arginine supplementation on glucose metabolism: a randomized, double-blind, placebo-controlled trialDiabetes Obes Metab.(2012 Oct)
- Nitric Oxide - Lucotti P, Setola E, Monti LD, Galluccio E, Costa S, Sandoli EP, Fermo I, Rabaiotti G, Gatti R, Piatti PBeneficial effects of a long-term oral L-arginine treatment added to a hypocaloric diet and exercise training program in obese, insulin-resistant type 2 diabetic patientsAm J Physiol Endocrinol Metab.(2006 Nov)
- Oxidative Stress Biomarkers - Jabłecka A, Bogdański P, Balcer N, Cieślewicz A, Skołuda A, Musialik KThe effect of oral L-arginine supplementation on fasting glucose, HbA1c, nitric oxide and total antioxidant status in diabetic patients with atherosclerotic peripheral arterial disease of lower extremitiesEur Rev Med Pharmacol Sci.(2012 Mar)
- Insulin - Isidori A, Lo Monaco A, Cappa MA study of growth hormone release in man after oral administration of amino acidsCurr Med Res Opin.(1981)
- Growth Hormone - Collier SR, Casey DP, Kanaley JAGrowth hormone responses to varying doses of oral arginineGrowth Horm IGF Res.(2005 Apr)
- Nitric Oxide - Liu TH, Wu CL, Chiang CW, Lo YW, Tseng HF, Chang CKNo effect of short-term arginine supplementation on nitric oxide production, metabolism and performance in intermittent exercise in athletesJ Nutr Biochem.(2009 Jun)
- Plasma Arginine - Wilson AM, Harada R, Nair N, Balasubramanian N, Cooke JPL-arginine supplementation in peripheral arterial disease: no benefit and possible harmCirculation.(2007 Jul 10)
- Nitric Oxide - Willoughby DS, Boucher T, Reid J, Skelton G, Clark MEffects of 7 days of arginine-alpha-ketoglutarate supplementation on blood flow, plasma L-arginine, nitric oxide metabolites, and asymmetric dimethyl arginine after resistance exerciseInt J Sport Nutr Exerc Metab.(2011 Aug)
- Nitric Oxide - Schwedhelm E, Maas R, Freese R, Jung D, Lukacs Z, Jambrecina A, Spickler W, Schulze F, Böger RHPharmacokinetic and pharmacodynamic properties of oral L-citrulline and L-arginine: impact on nitric oxide metabolismBr J Clin Pharmacol.(2008 Jan)
- Endothelial Function - Fahs CA, Heffernan KS, Fernhall BHemodynamic and vascular response to resistance exercise with L-arginineMed Sci Sports Exerc.(2009 Apr)
- Plasma Arginine - Bode-Böger SM, Böger RH, Galland A, Tsikas D, Frölich JCL-arginine-induced vasodilation in healthy humans: pharmacokinetic-pharmacodynamic relationshipBr J Clin Pharmacol.(1998 Nov)
- Nitric Oxide - Stephen J. Bailey, Paul G. Winyard, Anni Vanhatalo, Jamie R. Blackwell, Fred J. DiMenna, Daryl Paul Wilkerson, and Andrew M. JonesAcute L-arginine supplementation reduces the O2 cost of moderate-intensity exercise and enhances high-intensity exercise toleranceJournal of Applied Physiology.()
- Growth Hormone - Marcell TJ, Taaffe DR, Hawkins SA, Tarpenning KM, Pyka G, Kohlmeier L, Wiswell RA, Marcus ROral arginine does not stimulate basal or augment exercise-induced GH secretion in either young or old adultsJ Gerontol A Biol Sci Med Sci.(1999 Aug)
- Heart Rate - Wax B, Kavazis AN, Webb HE, Brown SPAcute L-arginine alpha ketoglutarate supplementation fails to improve muscular performance in resistance trained and untrained menJ Int Soc Sports Nutr.(2012 Apr 17)
- Blood Flow - Böger RH, Bode-Böger SM, Thiele W, Creutzig A, Alexander K, Frölich JCRestoring vascular nitric oxide formation by L-arginine improves the symptoms of intermittent claudication in patients with peripheral arterial occlusive diseaseJ Am Coll Cardiol.(1998 Nov)
- Growth Hormone - Abel T, Knechtle B, Perret C, Eser P, von Arx P, Knecht HInfluence of chronic supplementation of arginine aspartate in endurance athletes on performance and substrate metabolism - a randomized, double-blind, placebo-controlled studyInt J Sports Med.(2005 Jun)