Branched-Chain Amino Acids

Other Name(s):

Acide Isovalérique de Leucine, Acides Aminés à Chaîne Ramifiée, Acides Aminés Ramifiés, Aminoacidos Con Cadenas Laterales Ramificadas, BCAA, BCAAs, Branched Chain Amino Acid Therapy, Branched Chain Amino Acids, Isoleucine, Isoleucine Ethyl Ester HCl, Leucine, Leucine Ethyl Ester HCl, Leucine Isovaleric Acid, Leucine Methyl Ester HCl, L-Isoleucine, L-Leucine, L-Leucine Pyroglutamate, L-Valine, N-Acetyl Leucine, N-Acétyl Leucine, Valine, 2-amino-3-methylvaleric acid, 2-amino-4-methylvaleric acid, 2-amino-3-methylbutanoic acid.


Branched-chain amino acids are essential nutrients that the body obtains from proteins found in food, especially meat, dairy products, and legumes. They include leucine, isoleucine, and valine. “Branched-chain” refers to the chemical structure of these amino acids. People use branched-chain amino acids for medicine.

Branched-chain amino acids are used to treat amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease), brain conditions due to liver disease (chronic hepatic encephalopathy, latent hepatic encephalopathy), a movement disorder called tardive dyskinesia, a genetic disease called McArdle's disease, a disease called spinocerebellar degeneration, and poor appetite in elderly kidney failure patients and cancer patients. Branched-chain amino acids are also used to help slow muscle wasting in people who are confined to bed.

Some people use branched-chain amino acids to prevent fatigue and improve concentration.

Athletes use branched-chain amino acids to improve exercise performance and reduce protein and muscle breakdown during intense exercise.

Healthcare providers give branched-chain amino acids intravenously (by IV) for sudden brain swelling due to liver disease (acute hepatic encephalopathy) and also when the body has been under extreme stress, for example after serious injury or widespread infection.

How does it work?

Branched-chain amino acids stimulate the building of protein in muscle and possibly reduce muscle breakdown. Branched-chain amino acids seem to prevent faulty message transmission in the brain cells of people with advanced liver disease, mania, tardive dyskinesia, and anorexia.


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Uses & Effectiveness

Possibly Effective for...

  • Anorexia. Taking branched-chain amino acids by mouth seems to reduce anorexia and improve overall nutrition in older, undernourished people. There is also early evidence that taking branched-chain amino acids by mouth might be helpful for people with anorexia that is associated with cancer or liver disease.
  • Poor brain function related to liver disease. Although there are some conflicting results, most research suggests that taking branched-chain amino acids by mouth can improve liver and brain function in people with poor brain function caused by liver disease.
  • Mania. Consuming a drink containing the branched-chain amino acids leucine, isoleucine, and valine seems to reduce symptoms of mania.
  • Muscle breakdown. Taking branched-chain amino acids by mouth seems to reduce the breakdown of muscles during exercise
  • Movement disorder called tardive dyskinesia. Taking branched-chain amino acids by mouth seems to reduce symptoms of the muscle disorder called tardive dyskinesia.

Likely Ineffective for...

  • Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). Early studies showed promising results, but more recent studies show no benefit of branched chain amino acids in people with ALS. In fact, taking branched-chain amino acids might make lung function worse and increase the risk of death in people with this condition.

Insufficient Evidence to Rate Effectiveness for...

  • Liver disease caused by alcohol. Early research suggests that taking branched-chain amino acids daily along with a controlled diet does not reduce the risk of death in people with liver disease caused by drinking alcohol.
  • Athletic performance. There is inconsistent evidence about the effectiveness of branched-chain amino acids for athletic performance. Many studies suggest that taking branched-chain amino acids does not enhance exercise or athletic performance. However, other research suggests that it might reduce tiredness and muscle soreness associated with exercising.
  • Diabetes. Early research suggests that eating carbohydrates with an amino acid/protein mixture might improve insulin response in people with diabetes. However, it is not known if taking branched-chain amino acids as a supplement will provide the same benefits.
  • Liver cancer. Research suggests that drinking a beverage containing branched-chain amino acids daily for one year does not improve survival after surgical removal of liver cancer.
  • Liver cirrhosis. It is not clear if branched-chain amino acids benefit people with liver cirrhosis, the final phase of long-term liver disease. Early research suggests that branched-chain amino acids provide no benefit. However, there is some research that suggests branched-chain amino acids might improve quality of life in people with liver cirrhosis.
  • Genetic disorder that increases phenylalanine in the blood (Phenylketonuria). Taking branched-chain amino acids for up to 6 months seems to improve attention in children with phenylketonuria.
  • Disease of the spine called spinocerebellar degeneration (SCD). There are conflicting results about the effects of branched-chain amino acids in people with a disease of the spine called SCD. Some early research suggests that taking branched-chain amino acids by mouth might improve some symptoms of SCD. However, other research suggests that branched-chain amino acids do not improve muscle control in people with SCD.
  • Preventing fatigue.
  • Improving concentration.
  • Preventing muscle wasting in people confined to bed.
  • Other conditions.
More evidence is needed to rate the effectiveness of branched-chain amino acids for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

Side Effects

Branched-chain amino acids are LIKELY SAFE when injected intravenously (by IV) by a healthcare professional.

Branched-chain amino acids are POSSIBLY SAFE when taken by mouth appropriately. Some side effects are known to occur, such as fatigue and loss of coordination. Branched-chain amino acids should be used cautiously before or during activities where performance depends on motor coordination, such as driving.


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Special Precautions & Warnings

Pregnancy and breast-feeding: There is not enough reliable information about the safety of taking branched-chain amino acids if you are pregnant or breast feeding. Stay on the safe side and avoid use.

Children: Branched-chain amino acids are POSSIBLY SAFE for children when taken by mouth, short-term. Branched-chain amino acids have been used safely in children for up to 6 months.

Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease): The use of branched-chain amino acids has been linked with lung failure and higher death rates when used in patients with ALS. If you have ALS, do not use branched-chain amino acids until more is known.

Branched-chain ketoaciduria: Seizures and severe mental and physical retardation can result if intake of branched-chain amino acids is increased. Don't use branched-chain amino acids if you have this condition.

Chronic alcoholism: Dietary use of branched-chain amino acids in alcoholics has been associated with liver disease leading to brain damage (hepatic encephalopathy).

Low blood sugar in infants: Intake of one of the branched-chain amino acids, leucine, has been reported to lower blood sugar in infants with a condition called idiopathic hypoglycemia. This term means they have low blood sugar, but the cause is unknown. Some research suggests leucine causes the pancreas to release insulin, and this lowers blood sugar.

Surgery: Branched-chain amino acids might affect blood sugar levels, and this might interfere with blood sugar control during and after surgery. Stop using branched-chain amino acids at least 2 weeks before a scheduled surgery.


LevodopaInteraction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Branched-chain amino acids might decrease how much levodopa the body absorbs. By decreasing how much levodopa the body absorbs, branched-chain amino acids might decrease the effectiveness of levodopa. Do not take branched-chain amino acids and levodopa at the same time.

Medications for diabetes (Antidiabetes drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Branched-chain amino acids might decrease blood sugar. Diabetes medications are also used to lower blood sugar. Taking branched-chain amino acids 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.

Diazoxide (Hyperstat, Proglycem)Interaction Rating: Minor Be cautious with this combination.Talk with your health provider.

Branched-chain amino acids are used to help make proteins in the body. Taking diazoxide along with branched-chain amino acids might decrease the effects of branched-chain amino acids on proteins. More information is needed about this interaction.

Medications for inflammation (Corticosteroids)Interaction Rating: Minor Be cautious with this combination.Talk with your health provider.

Branched-chain amino acids are used to help make proteins in the body. Taking drugs called glucocorticoids along with branched-chain amino acids might decrease the effects of branched-chain amino acids on proteins. More information is needed about this interaction.

Thyroid hormoneInteraction Rating: Minor Be cautious with this combination.Talk with your health provider.

Branched-chain amino acids help the body make proteins. Some thyroid hormone medications can decrease how fast the body breaks down branched-chain amino acids. However, more information is needed to know the significance of this interaction.


The following doses have been studied in scientific research:


  • For a brain condition due to liver disease (hepatic encephalopathy): 240 mg/kg/day up to 25 grams of branched-chain amino acids.
  • For mania: a 60 gram branched-chain amino acid drink containing valine, isoleucine, and leucine in a ratio of 3:3:4 every morning for 7 days.
  • For tardive dyskinesia: a branched-chain amino acid drink containing valine, isoleucine, and leucine at a dose of 222 mg/kg taken three times daily for 3 weeks.
  • For anorexia and improving overall nutrition in elderly malnourished hemodialysis patients: granules of branched-chain amino acids consisting of valine, leucine, and isoleucine at a dose of 4 grams taken three times daily.
The estimated average requirement (EAR) of branched-chain amino acids is 68 mg/kg/day (leucine 34 mg, isoleucine 15 mg, valine 19 mg) for adults. However, some researchers think earlier testing methods may have underestimated this requirement and that the requirement is really about 144 mg/kg/day. Other researchers think the EARs for children are also low. EARs for branched-chain amino acids for children are: ages 7-12 months, 134 mg/kg/day; 1-3 years, 98 mg/kg/day; 4-8 years, 81 mg/kg/day; boys 9-13 years, 81 mg/kg/day; girls 9-13 years, 77 mg/kg/day; boys 14-18 years, 77 mg/kg/day; girls 14-18 years, 71 mg/kg/day.


  • Healthcare providers give branched-chain amino acids intravenously (by IV) for brain enlargement due to liver disease (hepatic encephalopathy).

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Askanazi, J., Furst, P., Michelsen, C. B., Elwyn, D. H., Vinnars, E., Gump, F. E., Stinchfield, F. E., and Kinney, J. M. Muscle and plasma amino acids after injury: hypocaloric glucose vs. amino acid infusion. Ann Surg. 1980;191(4):465-472. View abstract.

Bassit, R. A., Sawada, L. A., Bacurau, R. F., Navarro, F., and Costa Rosa, L. F. The effect of BCAA supplementation upon the immune response of triathletes. Med Sci Sports Exerc. 2000;32(7):1214-1219. View abstract.

Berry, H. K., Brunner, R. L., Hunt, M. M., and White, P. P. Valine, isoleucine, and leucine. A new treatment for phenylketonuria. Am J Dis Child 1990;144(5):539-543. View abstract.

Bigard, A. X., Lavier, P., Ullmann, L., Legrand, H., Douce, P., and Guezennec, C. Y. Branched-chain amino acid supplementation during repeated prolonged skiing exercises at altitude. Int.J Sport Nutr 1996;6(3):295-306. View abstract.

Biolo, G., De, Cicco M., Dal, Mas, V, Lorenzon, S., Antonione, R., Ciocchi, B., Barazzoni, R., Zanetti, M., Dore, F., and Guarnieri, G. Response of muscle protein and glutamine kinetics to branched-chain-enriched amino acids in intensive care patients after radical cancer surgery. Nutrition 2006;22(5):475-482. View abstract.

Blomstrand, E. and Newsholme, E. A. Effect of branched-chain amino acid supplementation on the exercise-induced change in aromatic amino acid concentration in human muscle. Acta Physiol Scand. 1992;146(3):293-298. View abstract.

Blomstrand, E. and Saltin, B. BCAA intake affects protein metabolism in muscle after but not during exercise in humans. Am J Physiol Endocrinol.Metab 2001;281(2):E365-E374. View abstract.

Blomstrand, E., Andersson, S., Hassmen, P., Ekblom, B., and Newsholme, E. A. Effect of branched-chain amino acid and carbohydrate supplementation on the exercise-induced change in plasma and muscle concentration of amino acids in human subjects. Acta Physiol Scand. 1995;153(2):87-96. View abstract.

Blomstrand, E., Hassmen, P., Ekblom, B., and Newsholme, E. A. Administration of branched-chain amino acids during sustained exercise--effects on performance and on plasma concentration of some amino acids. Eur J Appl.Physiol Occup.Physiol 1991;63(2):83-88. View abstract.

Blomstrand, E., Moller, K., Secher, N. H., and Nybo, L. Effect of carbohydrate ingestion on brain exchange of amino acids during sustained exercise in human subjects. Acta Physiol Scand. 2005;185(3):203-209. View abstract.

Bodamer, O. A., Hussein, K., Morris, A. A., Langhans, C. D., Rating, D., Mayatepek, E., and Leonard, J. V. Glucose and leucine kinetics in idiopathic ketotic hypoglycaemia. Arch.Dis Child 2006;91(6):483-486. View abstract.

Borsheim, E., Bui, Q. U., and Wolfe, R. R. Plasma amino acid concentrations during late rehabilitation in patients with traumatic brain injury. Arch.Phys.Med Rehabil. 2007;88(2):234-238. View abstract.

Bossola, M., Scribano, D., Colacicco, L., Tavazzi, B., Giungi, S., Zuppi, C., Luciani, G., and Tazza, L. Anorexia and plasma levels of free tryptophan, branched chain amino acids, and ghrelin in hemodialysis patients. J Ren Nutr 2009;19(3):248-255. View abstract.

Brosnan, J. T. and Brosnan, M. E. Branched-chain amino acids: enzyme and substrate regulation. J Nutr 2006;136(1 Suppl):207S-211S. View abstract.

Calvey, H., Davis, M., and Williams, R. Controlled trial of nutritional supplementation, with and without branched chain amino acid enrichment, in treatment of acute alcoholic hepatitis. J Hepatol. 1985;1(2):141-151. View abstract.

Carli, G., Bonifazi, M., Lodi, L., Lupo, C., Martelli, G., and Viti, A. Changes in the exercise-induced hormone response to branched chain amino acid administration. Eur J Appl.Physiol Occup.Physiol 1992;64(3):272-277. View abstract.

Chuang, J. C., Yu, C. L., and Wang, S. R. Modulation of human lymphocyte proliferation by amino acids. Clin Exp.Immunol. 1990;81(1):173-176. View abstract.

Colker CM, Swain MA Fabrucini B Shi Q Kalman DS. Effects of supplemental protein on body composition and muscular strength in healthy athletic male adults. Current Therapeutic Research, Clinical & Experimental 2000;61(1):19-28.

Davis, J. M., Welsh, R. S., De Volve, K. L., and Alderson, N. A. Effects of branched-chain amino acids and carbohydrate on fatigue during intermittent, high-intensity running. Int.J Sports Med 1999;20(5):309-314. View abstract.

De Palo EF, Metus P Gatti R Previti O Bigon L De Palo CB. Branched chain amino acids chronic treatment and muscular exercise performance in athletes: a study through plasma acetyl-carnitine levels. Amino Acids 1993;4(3):255-266.

di, Luigi L., Guidetti, L., Pigozzi, F., Baldari, C., Casini, A., Nordio, M., and Romanelli, F. Acute amino acids supplementation enhances pituitary responsiveness in athletes. Med Sci Sports Exerc. 1999;31(12):1748-1754. View abstract.

Egberts, E. H., Schomerus, H., Hamster, W., and Jurgens, P. [Branched-chain amino acids in the treatment of latent porto-systemic encephalopathy. A placebo-controlled double-blind cross-over study]. Z.Ernahrungswiss. 1986;25(1):9-28. View abstract.

Engelen, M. P., Rutten, E. P., De Castro, C. L., Wouters, E. F., Schols, A. M., and Deutz, N. E. Supplementation of soy protein with branched-chain amino acids alters protein metabolism in healthy elderly and even more in patients with chronic obstructive pulmonary disease. Am J Clin Nutr 2007;85(2):431-439. View abstract.

Eriksson, L. S., Persson, A., and Wahren, J. Branched-chain amino acids in the treatment of chronic hepatic encephalopathy. Gut 1982;23(10):801-806. View abstract.

Essen-Gustavsson, B. and Blomstrand, E. Effect of exercise on concentrations of free amino acids in pools of type I and type II fibres in human muscle with reduced glycogen stores. Acta Physiol Scand. 2002;174(3):275-281. View abstract.

Evangeliou, A., Spilioti, M., Doulioglou, V., Kalaidopoulou, P., Ilias, A., Skarpalezou, A., Katsanika, I., Kalamitsou, S., Vasilaki, K., Chatziioanidis, I., Garganis, K., Pavlou, E., Varlamis, S., and Nikolaidis, N. Branched chain amino acids as adjunctive therapy to ketogenic diet in epilepsy: pilot study and hypothesis. J Child Neurol. 2009;24(10):1268-1272. View abstract.

Freyssenet, D., Berthon, P., Denis, C., Barthelemy, J. C., Guezennec, C. Y., and Chatard, J. C. Effect of a 6-week endurance training programme and branched-chain amino acid supplementation on histomorphometric characteristics of aged human muscle. Arch.Physiol Biochem 1996;104(2):157-162. View abstract.

Gaine, P. C., Pikosky, M. A., Bolster, D. R., Martin, W. F., Maresh, C. M., and Rodriguez, N. R. Postexercise whole-body protein turnover response to three levels of protein intake. Med Sci Sports Exerc. 2007;39(3):480-486. View abstract.

Gamrin, L., Berg, H. E., Essen, P., Tesch, P. A., Hultman, E., Garlick, P. J., McNurlan, M. A., and Wernerman, J. The effect of unloading on protein synthesis in human skeletal muscle. Acta Physiol Scand. 1998;163(4):369-377. View abstract.

Ganzit GP, Benzio S Filippa M Goitra B Severin B Gribaudo CG. Effects of oral branched-chain amino acids supplementation in bodybuilders. Medicina Dello Sport 1997;50(3):293-303.

Gibala, M. J. Regulation of skeletal muscle amino acid metabolism during exercise. Int.J Sport Nutr Exerc.Metab 2001;11(1):87-108. View abstract.

Gil R and Neau JP. A double-blind placebo controlled study of branched chain amino acids and L-threonine for the short-term treatment of signs and symptoms of amyotrophic lateral sclerosis. La semaine des (Paris) 1992;68:1472-1475.

Gomez-Merino, D., Bequet, F., Berthelot, M., Riverain, S., Chennaoui, M., and Guezennec, C. Y. Evidence that the branched-chain amino acid L-valine prevents exercise-induced release of 5-HT in rat hippocampus. Int.J Sports Med 2001;22(5):317-322. View abstract.

Greer, B. K., Woodard, J. L., White, J. P., Arguello, E. M., and Haymes, E. M. Branched-chain amino acid supplementation and indicators of muscle damage after endurance exercise. Int.J Sport Nutr Exerc.Metab 2007;17(6):595-607. View abstract.

Grungreiff K, Kleine F-D Musil HE Diete U Franke D Klauck S Page I Kleine S Lossner B Pfeiffer KP. Valine enriched branched-chain amino acids in the treatment of hepatic encephalopathy. Enzephalopathie Z.Gastroenterol. 1993;31(4):235-241.

Habu, D., Nishiguchi, S., Nakatani, S., Lee, C., Enomoto, M., Tamori, A., Takeda, T., Ohfuji, S., Fukushima, W., Tanaka, T., Kawamura, E., and Shiomi, S. Comparison of the effect of BCAA granules on between decompensated and compensated cirrhosis. Hepatogastroenterology 2009;56(96):1719-1723. View abstract.

Hood, D. A. and Terjung, R. L. Amino acid metabolism during exercise and following endurance training. Sports Med 1990;9(1):23-35. View abstract.

Hoppe, C., Molgaard, C., Vaag, A., Barkholt, V., and Michaelsen, K. F. High intakes of milk, but not meat, increase s-insulin and insulin resistance in 8-year-old boys. Eur J Clin Nutr 2005;59(3):393-398. View abstract.

Jackman, S. R., Witard, O. C., Jeukendrup, A. E., and Tipton, K. D. Branched-chain amino acid ingestion can ameliorate soreness from eccentric exercise. Med Sci Sports Exerc. 2010;42(5):962-970. View abstract.

Jimenez Jimenez, F. J., Ortiz, Leyba C., Garcia Garmendia, J. L., Garnacho, Montero J., Rodriguez Fernandez, J. M., and Espigado, Tocino, I. [Prospective comparative study of different amino acid and lipid solutions in parenteral nutrition of patients undergoing bone marrow transplantation]. Nutr Hosp. 1999;14(2):57-66. View abstract.

Kalkan, Ucar S., Coker, M., Habif, S., Saz, E. U., Karapinar, B., Ucar, H., Kitis, O., and Duran, M. The first use of N-carbamylglutamate in a patient with decompensated maple syrup urine disease. Metab Brain Dis 2009;24(3):409-414. View abstract.

Kalogeropoulou, D., Lafave, L., Schweim, K., Gannon, M. C., and Nuttall, F. Q. Leucine, when ingested with glucose, synergistically stimulates insulin secretion and lowers blood glucose. Metabolism 2008;57(12):1747-1752. View abstract.

Kawamura, E., Habu, D., Morikawa, H., Enomoto, M., Kawabe, J., Tamori, A., Sakaguchi, H., Saeki, S., Kawada, N., and Shiomi, S. A randomized pilot trial of oral branched-chain amino acids in early cirrhosis: validation using prognostic markers for pre-liver transplant status. Liver Transpl. 2009;15(7):790-797. View abstract.

Koivusalo, A. M., Teikari, T., Hockerstedt, K., and Isoniemi, H. Albumin dialysis has a favorable effect on amino acid profile in hepatic encephalopathy. Metab Brain Dis 2008;23(4):387-398. View abstract.

Koopman, R., Verdijk, L. B., Beelen, M., Gorselink, M., Kruseman, A. N., Wagenmakers, A. J., Kuipers, H., and van Loon, L. J. Co-ingestion of leucine with protein does not further augment post-exercise muscle protein synthesis rates in elderly men. Br.J Nutr 2008;99(3):571-580. View abstract.

Koopman, R., Verdijk, L., Manders, R. J., Gijsen, A. P., Gorselink, M., Pijpers, E., Wagenmakers, A. J., and van Loon, L. J. Co-ingestion of protein and leucine stimulates muscle protein synthesis rates to the same extent in young and elderly lean men. Am J Clin Nutr 2006;84(3):623-632. View abstract.

Kutsuzawa, T., Shioya, S., Kurita, D., and Haida, M. Plasma branched-chain amino acid levels and muscle energy metabolism in patients with chronic obstructive pulmonary disease. Clin Nutr 2009;28(2):203-208. View abstract.

Long-term oral administration of branched chain amino acids after curative resection of hepatocellular carcinoma: a prospective randomized trial. The San-in Group of Liver Surgery. Br.J Surg. 1997;84(11):1525-1531. View abstract.

Madsen, K., MacLean, D. A., Kiens, B., and Christensen, D. Effects of glucose, glucose plus branched-chain amino acids, or placebo on bike performance over 100 km. J Appl.Physiol 1996;81(6):2644-2650. View abstract.

Malgorzewicz, S., Debska-Slizien, A., Rutkowski, B., and Lysiak-Szydlowska, W. Serum concentration of amino acids versus nutritional status in hemodialysis patients. J Ren Nutr 2008;18(2):239-247. View abstract.

Marchesini, G., Bianchi, G., Merli, M., Amodio, P., Panella, C., Loguercio, C., Rossi, Fanelli F., and Abbiati, R. Nutritional supplementation with branched-chain amino acids in advanced cirrhosis: a double-blind, randomized trial. Gastroenterology 2003;124(7):1792-1801. View abstract.

Matsumoto, K., Koba, T., Hamada, K., Sakurai, M., Higuchi, T., and Miyata, H. Branched-chain amino acid supplementation attenuates muscle soreness, muscle damage and inflammation during an intensive training program. J Sports Med Phys.Fitness 2009;49(4):424-431. View abstract.

Matsumoto, K., Koba, T., Hamada, K., Tsujimoto, H., and Mitsuzono, R. Branched-chain amino acid supplementation increases the lactate threshold during an incremental exercise test in trained individuals. J Nutr Sci Vitaminol.(Tokyo) 2009;55(1):52-58. View abstract.

Mendenhall, C., Bongiovanni, G., Goldberg, S., Miller, B., Moore, J., Rouster, S., Schneider, D., Tamburro, C., Tosch, T., and Weesner, R. VA Cooperative Study on Alcoholic Hepatitis. III: Changes in protein-calorie malnutrition associated with 30 days of hospitalization with and without enteral nutritional therapy. JPEN J Parenter.Enteral Nutr 1985;9(5):590-596. View abstract.

Mikulski, T., Ziemba, A, Chmura J., Wisnik P., Kurek Z., Kaciuba, Uscilko H., and Nazar, K. The effect of supplementation with branched chain amino acids (BCAA) on psychomotor performance during graded exercise in human subjects. Biology of sport (Warsaw), 2002;19(4):295-301.

Mittleman, K. D., Ricci, M. R., and Bailey, S. P. Branched-chain amino acids prolong exercise during heat stress in men and women. Med Sci Sports Exerc. 1998;30(1):83-91. View abstract.

Moore, D. R., Robinson, M. J., Fry, J. L., Tang, J. E., Glover, E. I., Wilkinson, S. B., Prior, T., Tarnopolsky, M. A., and Phillips, S. M. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am J Clin Nutr 2009;89(1):161-168. View abstract.

Morgan, M. Y., Hawley, K. E., and Stambuk, D. Amino acid tolerance in cirrhotic patients following oral protein and amino acid loads. Aliment.Pharmacol.Ther 1990;4(2):183-200. View abstract.

Mori, M., Adachi, Y., Mori, N., Kurihara, S., Kashiwaya, Y., Kusumi, M., Takeshima, T., and Nakashima, K. Double-blind crossover study of branched-chain amino acid therapy in patients with spinocerebellar degeneration. J Neurol.Sci 3-30-2002;195(2):149-152. View abstract.

Nakaya, Y., Okita, K., Suzuki, K., Moriwaki, H., Kato, A., Miwa, Y., Shiraishi, K., Okuda, H., Onji, M., Kanazawa, H., Tsubouchi, H., Kato, S., Kaito, M., Watanabe, A., Habu, D., Ito, S., Ishikawa, T., Kawamura, N., and Arakawa, Y. BCAA-enriched snack improves nutritional state of cirrhosis. Nutrition 2007;23(2):113-120. View abstract.

Nilsson, M., Holst, J. J., and Bjorck, I. M. Metabolic effects of amino acid mixtures and whey protein in healthy subjects: studies using glucose-equivalent drinks. Am J Clin Nutr 2007;85(4):996-1004. View abstract.

Nozaki, S., Tanaka, M., Mizuno, K., Ataka, S., Mizuma, H., Tahara, T., Sugino, T., Shirai, T., Eguchi, A., Okuyama, K., Yoshida, K., Kajimoto, Y., Kuratsune, H., Kajimoto, O., and Watanabe, Y. Mental and physical fatigue-related biochemical alterations. Nutrition 2009;25(1):51-57. View abstract.

Poortmans, J., Parry, Billings M., Duchateau, J., Leclercq, R., Brasseur, M., and Newsholme, E. Plasma amino acid and cytokine concentrations following a marathon race. Portuguese journal of human performance studies (Lisboa) 1993;9(1):9-14.

Portier, H., Chatard, J. C., Filaire, E., Jaunet-Devienne, M. F., Robert, A., and Guezennec, C. Y. Effects of branched-chain amino acids supplementation on physiological and psychological performance during an offshore sailing race. Eur J Appl.Physiol 2008;104(5):787-794. View abstract.

Rossi-Fanelli, F., Riggio, O., Cangiano, C., Cascino, A., De, Conciliis D., Merli, M., Stortoni, M., and Giunchi, G. Branched-chain amino acids vs lactulose in the treatment of hepatic coma: a controlled study. Dig.Dis Sci 1982;27(10):929-935. View abstract.

Saito, Y., Saito, H., Nakamura, M., Wakabayashi, K., Takagi, T., Ebinuma, H., and Ishii, H. Effect of the molar ratio of branched-chain to aromatic amino acids on growth and albumin mRNA expression of human liver cancer cell lines in a serum-free medium. Nutr Cancer 2001;39(1):126-131. View abstract.

Schena, F., Guerrini, F., Tregnaghi, P., and Kayser, B. Branched-chain amino acid supplementation during trekking at high altitude. The effects on loss of body mass, body composition, and muscle power. Eur J Appl.Physiol Occup.Physiol 1992;65(5):394-398. View abstract.

Scholl-Burgi, S., Haberlandt, E., Heinz-Erian, P., Deisenhammer, F., Albrecht, U., Sigl, S. B., Rauchenzauner, M., Ulmer, H., and Karall, D. Amino acid cerebrospinal fluid/plasma ratios in children: influence of age, gender, and antiepileptic medication. Pediatrics 2008;121(4):e920-e926. View abstract.

Schon, M. R., Heil, W., Lemmens, H. P., Padval, D., Matthes, M., Puhl, G., Neuhaus, P., and Hammer, C. Xenogeneic, extracorporeal liver perfusion in primates improves the ratio of branched-chain amino acids to aromatic amino acids (Fischer's ratio). Eur Surg.Res 1999;31(3):230-239. View abstract.

Sun, L. C., Shih, Y. L., Lu, C. Y., Hsieh, J. S., Chuang, J. F., Chen, F. M., Ma, C. J., and Wang, J. Y. Randomized, controlled study of branched chain amino acid-enriched total parenteral nutrition in malnourished patients with gastrointestinal cancer undergoing surgery. Am Surg. 2008;74(3):237-242. View abstract.

Watson, P., Shirreffs, S. M., and Maughan, R. J. The effect of acute branched-chain amino acid supplementation on prolonged exercise capacity in a warm environment. Eur J Appl.Physiol 2004;93(3):306-314. View abstract.

Young, V. R., Bier, D. M., and Pellett, P. L. A theoretical basis for increasing current estimates of the amino acid requirements in adult man, with experimental support. Am J Clin Nutr 1989;50(1):80-92. View abstract.

Zanetti, M., Barazzoni, R., Kiwanuka, E., and Tessari, P. Effects of branched-chain-enriched amino acids and insulin on forearm leucine kinetics. Clin Sci (Lond) 1999;97(4):437-448. View abstract.

Zello, G. A., Wykes, L. J., Ball, R. O., and Pencharz, P. B. Recent advances in methods of assessing dietary amino acid requirements for adult humans. J Nutr 1995;125(12):2907-2915. View abstract.

Anon. Branched-chain amino acids and amyotrophic lateral sclerosis: a treatment failure? The Italian ALS Study Group. Neurology 1993;43:2466-70. View abstract.

Anthony JC, Anthony TG, Kimball SR, Jefferson LS. Signaling pathways involved in translational control of protein synthesis in skeletal muscle by leucine. J Nutr 2001;131:856S-60S.. View abstract.

Anthony JC, Lang CH, Crozier SJ, et al. Contribution of insulin to the translational control of protein synthesis in skeletal muscle by leucine. Am J Physiol Endocrinol Metab 282:E1092-101.. View abstract.

Aquilani R. Oral amino acid administration in patients with diabetes mellitus: supplementation or metabolic therapy? Am J Cardiol 2004;93:21A-22A.. View abstract.

Blomstrand E, Ek S, Newsholme EA. Influence of ingesting a solution of branched-chain amino acids on plasma and muscle concentrations of amino acids during prolonged submaximal exercise. Nutrition 1996;12:485-90. View abstract.

Blomstrand E, Hassmen P, Ek S, et al. Influence of ingesting a solution of branched-chain amino acids on perceived exertion during exercise. Acta Physiol Scand 1997;159:41-9. View abstract.

Branchey L, Branchey M, Shaw S, Lieber CS. Relationship between changes in plasma amino acids and depression in alcoholic patients. Am J Psychiatry 1984;141:1212-5. View abstract.

Cangiano C, Laviano A, Meguid MM, et al. Effects of administration of oral branched-chain amino acids on anorexia and caloric intake in cancer patients. J Natl Cancer Inst 1996;88:550-2.

Chuah SY, Ellis BJ, Mayberry JF. Exacerbation of hepatic encephalopathy by branched-chain amino acids-a case report. J Hum Nutr Diet 1992;5:53-6.

DiPiro JT, Talbert RL, Yee GC, et al; eds. Pharmacotherapy: A pathophysiologic approach. 4th ed. Stamford, CT: Appleton & Lange, 1999.

Egberts EH, Schomerus H, Hamster W, Jurgens P. Branched chain amino acids in the treatment of latent portosystemic encephalopathy. A double-blind, placebo-controlled, crossover study. Gastroenterology 1985;88:887-95. View abstract.

Fabbri A, Magrini N, Bianchi G, et al. Overview of randomized clinical trials of oral branched-chain amino acid treatment in chronic hepatic encephalopathy. JPEN J Parenter Enteral Nutr 1996;20:159-64. View abstract.

Facts and Comparisons staff. Drug Facts and Comparisons. St Louis: Wolters Kluwer Company (updated monthly).

Food and Drug Administration. A Catalog of FDA Approved Drug Products. Available at: (Accessed 28 June 2005).

Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients). Washington, DC: National Academy Press, 2002. Available at:

Gietzen DW, Magrum LJ. Molecular mechanisms in the brain involved in the anorexia of branced-chain amino acid deficiency. J Nutr 2001;131:851S-5S.. View abstract.

Harris RA, Kobayashi R, Murakami T, Shimomura Y. Regulation of branched-chain alpha-keto acid dehydrogenase kinase expression in rat liver. J Nutr 2001;131:841S-5S.. View abstract.

Hiroshige K, Sonta T, Suda T, et al. Oral supplementation of branched-chain amino acid improves nutritional status in elderly patients on chronic haemodialysis. Nephrol Dial Transplant 2001;16:1856-62.. View abstract.

Hutson SM, Harris RA. Introduction. Symposium: Leucine as a nutritional signal. J Nutr 2001;131:839S-40S.

Hutson SM, Lieth E, LaNoue KF. Function of leucine in excitatory neurotransmitter metabolism in the central nervous system. J Nutr 2001;131:846S-50S.. View abstract.

Institute of Medicine. The role of protein and amino acids in sustaining and enhancing performance. Washington, DC: National Academy Press, 1999. Available at:

Kimball SR, Farrell PA, Jefferson LS. Invited review: Role of insulin in translational control of protein synthesis in skeletal muscle by amino acids or excercise. J Appl Physiol 2002;93:1168-80.. View abstract.

Kimball SR, Jefferson LS. Control of protein synthesis by amino acid availability. Curr Opin Clin Nutr Metab Care 2002;5:63-7.. View abstract.

Layman DK. The role of leucine in weight loss diets and glucose homeostasis. J Nutr 2003;133:261S-7S.. View abstract.

Lynch CJ, Hutson SM, Patson BJ, et al. Tissue-specific effects of chronic dietary leucine and norleucine supplementation on protein synthesis in rats. Am J Physiol Endocrinol Metab 2002; 283:E824-35.. View abstract.

Lynch CJ. Role of leucine in the regulation of mTOR by amino acids: revelations from structure-activity studies. J Nutr 2001;131:861S-5S.. View abstract.

MacLean DA, Graham TE, Saltin B. Branched-chain amino acids augment ammonia metabolism while attenuating protein breakdown during exercise. Am J Physiol 1994;267:E1010-22. View abstract.

MacLean DA, Graham TE. Branched-chain amino acid supplementation augments plasma ammonia responses during exercise in humans. J Appl Physiol 1993;74:2711-7. View abstract.

Mager DR, Wykes LJ, Ball RO, Pencharz PB. Branched-chain amino acid requirements in school-aged children determined by indicator amino acid oxidation (IAAO). J Nutr 2003;133:3540-5. View abstract.

Majumdar SK, Shaw GK, Thomson AD, et al. Changes in plasma amino acid patterns in chronic alcoholic patients during ethanol withdrawal syndrome: their clinical implications. Med Hypotheses 1983;12:239-51. View abstract.

Marchesini G, Bianchi G, Rossi B, et al. Nutritional treatment with branched-chain amino acids in advanced liver cirrhosis. J Gastroenterol 2000;35:7-12. View abstract.

Marchesini G, Dioguardi FS, Bianchi GP, et al. Long-term oral branched-chain amino acid treatment in chronic hepatic encephalopathy. A randomized double-blind casein-controlled trial. The Italian Multicenter Study Group. J Hepatol 1990;11:92-101. View abstract.

Michel H, Bories P, Aubin JP, et al. Treatment of acute hepatic encephalopathy in cirrhotics with a branched-chain amino acids enriched versus a conventional amino acids mixture. A controlled study of 70 patients. Liver 1985;5:282-9. View abstract.

Mori N, Adachi Y, Takeshima T, et al. Branched-chain amino acid therapy for spinocerebellar degeneration: a pilot clinical crossover trial. Intern Med 1999;38:401-6. View abstract.

Naylor CD, O'Rourke K, Detsky AS, Baker JP. Parenteral nutrition with branched-chain amino acids in hepatic encephalopathy. A meta-analysis. Gastroenterology 1989;97:1033-42. View abstract.

O'Keefe SJ, Ogden J, Dicker J. Enteral and parenteral branched chain amino acid-supplemented nutritional support in patients with encephalopathy due to alcoholic liver disease. JPEN J Parenter Enteral Nutr 1987;11:447-53. View abstract.

Partin JF, Pushkin YR. Tachyarrhythmia and hypomania with horny goat weed. Psychosomatics 2004;45:536-7. View abstract.

Plaitakis A, Smith J, Mandeli J, Yahr MD. Pilot trial of branched-chain aminoacids in amyotrophic lateral sclerosis. Lancet 1988;1:1015-8. View abstract.

Plauth M, Egberts EH, Hamster W, et al. Long-term treatment of latent portosystemic encephalopathy with branched-chain amino acids. A double-blind placebo-controlled crossover study. J Hepatol 1993;17:308-14. View abstract.

Proud CG. Regulation of mammalian translation factors by nutrients. Eur J Biochem 2002;269:5338-49.. View abstract.

Richardson MA, Bevans ML, Read LL, et al. Efficacy of the branched-chain amino acids in the treatment of tardive dyskinesia in men. Am J Psychiatry 2003;160:1117-24.. View abstract.

Richardson MA, Bevans ML, Weber JB, et al. Branched chain amino acids decrease tardive dyskinesia symptoms. Psychopharmacology (Berl) 1999;143:358-64. View abstract.

Richardson MA, Small AM, Read LL, et al. Branched chain amino acid treatment of tardive dyskinesia in children and adolescents. J Clin Psychiatry 2004;65:92-6. View abstract.

Riordan SM, Williams R. Treatment of Hepatic Encephalopathy. N Engl J Med 1997;337:473-9.

Rosen HM, Yoshimura N, Hodgman JM, Fischer JE. Plasma amino acid patterns in hepatic encephalopathy of differing etiology. Gastroenterology 1977;72:483-7. View abstract.

Rossi Fanelli F, Cangiano C, Capocaccia L, et al. Use of branched chain amino acids for treating hepatic encephalopathy: clinical experiences. Gut 1986;27:111-5. View abstract.

Scarna A, Gijsman HJ, McTavish SF, et al. Effects of a branched-chain amino acid drink in mania. Br J Psychiatry 2003;182:210-3.. View abstract.

Stein TP, Schluter MD, Leskiw MJ, Boden G. Attenuation of the protein wasting associated with bed rest by branched-chain amino acids. Nutrition 1999;15:656-60. View abstract.

Suryawan A, Hawes JW, Harris RA, et al. A molecular model of human branched-chain amino acid metabolism. Am J Clin Nutr 1998;68:72-81. View abstract.

Tandan R, Bromberg MB, Forshew D, et al. A controlled trial of amino acid therapy in amyotrophic lateral sclerosis: I. Clinical, functional, and maximum isometric torque data. Neurology 1996;47:1220-6. View abstract.

Testa D, Caraceni T, Fetoni V. Branched-chain amino acids in the treatment of amyotrophic lateral sclerosis. J Neurol 1989;236:445-7. View abstract.

van Hall G, Raaymakers JS, Saris WH. Ingestion of branched-chain amino acids and tryptophan during sustained exercise in man: failure to affect performance. J Physiol (Lond) 1995;486:789-94. View abstract.

van Loon LJ, Kruijshoop M, Menheere PP, et al. Amino acid ingestion strongly enhances insulin secretion in patients with long-term type 2 diabetes. Diabetes Care 2003;26:625-30. View abstract.

Vilstrup H, Gluud C, Hardt F, et al. Branched chain enriched amino acid versus glucose treatment of hepatic encephalopathy. A double-blind study of 65 patients with cirrhosis. J Hepatol 1990;10:291-6. View abstract.

Wahren J, Denis J, Desurmont P, Eriksson LS, et al. Is intravenous administration of branched chain amino acids effective in the treatment of hepatic encephalopathy? A multicenter study. Hepatol 1983;3:475-80. View abstract.

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