BCAA Injection

Branched-chain amino acids (isoleucine, leucine, and valine) are considered essential nutrients.^[1] Essential nutrients are those that cannot be made by the human body and must instead be obtained through diet.^[1]

Branched-chain amino acids (BCAAs) are usually obtained in the diet from protein.^[2] To maintain muscle mass, the standard recommended protein consumption is 0.8 g/kg daily.^[2] However, modern recommendations are even higher.^[2] In males, the average daily protein intake is 1.7g/kg.^[2] Per Neinast et al., BCAAs make up about 2-5% of energy sources from the diet.^[2] According to the Institute of Medicine, the Estimated Average Requirements for leucine, isoleucine, and valine are 34, 15, and 19 mg/kg per day, respectively.^[1]

In the body, BCAAs may contribute to the formation of new proteins.^[2] Per Neinast et al., BCAAs assist with the anabolic signal needed for protein synthesis.^[2] In an animal study, leucine was the most potent BCAA in stimulating protein synthesis in skeletal muscle.^[3] This effect on protein synthesis has generated an interest in the potential use of BCAAs as a supplement to exercise.^[2] However, a study that focused on BCAA infusion in humans suggested that BCAAs reduce protein breakdown, but do not affect protein synthesis.^[4] These conflicting results may be due to differences in animal and human physiology.^[4]

The balance between muscle protein breakdown and protein synthesis influences muscle mass.^[5] If the rate of muscle protein synthesis is greater than the rate of protein breakdown, the result is a gain of muscle mass.^[5] The human body depends on the availability of essential amino acids to synthesize protein.^[5] These essential amino acids may be obtained from the breakdown of other proteins or through supplementation but cannot be newly synthesized by the body.^[5]

One study found that the addition of BCAAs to a 6.25 g whey protein drink increased muscle protein synthesis to a similar level achieved by a larger 25 g whey protein drink administered alone.^[5] The whey protein provided the essential amino acids necessary for protein creation, suggesting that BCAAs may be rate limiting for muscle protein formation by whey protein.^[5] The administration of BCAA alone in humans may not increase protein synthesis due to a lack of available essential amino acids.^[5]

Muscle protein synthesis in the body requires the presence of amino acids.^[5] When these necessary amino acids are present, BCAAs may help increase protein synthesis by activating the anabolic signaling pathway.^[5] The human body’s processes are complex, so more research is needed to understand the role of BCAA therapy.

Patients with maple syrup urine disease (MSUD) should also avoid BCAAs. Maple syrup urine disease is a rare condition in which your body can’t break down certain amino acids.^{[6] [7]}

BCAA supplements may put additional strain on the kidneys, particularly in individuals with existing kidney issues. If you have kidney problems or a history of kidney disease, it’s important to consult with a healthcare professional before taking BCAA supplements.

Some individuals may have allergies or sensitivities to BCAAs or other ingredients commonly found in BCAA supplements. It’s important to check the ingredients list and consult with a healthcare provider if you have any concerns about potential allergic reactions.^[8]

BCAAs may interact with medications, including thyroid hormones, drugs for Parkinson’s, and medicines for diabetes.

Common side effects can include fatigue, loss of coordination, nausea, headaches, and increased insulin resistance. BCAAs side effects may affect blood sugar levels, requiring caution from those patients with diabetes or prediabetes. BCAAs should be avoided for a period before and after surgery. Studies have suggested BCAAs could influence serotonin synthesis.^[11]

BCAA’s should not be used in pregnant women. Pre-clinical studies have shown abnormal fetal and placental growth in the first few weeks of pregnancy. Another study showed an increased risk in gestational diabetes when taken in early pregnancy.^[9]

The safety of BCAA injection has not been well evaluated in women who are breastfeeding. Due to this lack of safety data, women who are breastfeeding and should avoid BCAA injection.^[10]

Store this medication at 68°F to 77°F (20°C to 25°C) and away from heat, moisture and light. Keep all medicine out of the reach of children. Throw away any unused medicine after the beyond-use date. Do not flush unused medications or pour down a sink or drain.

1. Institute of Medicine (US) Committee on Nutrition, Trauma, and the Brain; Erdman J, Oria M, Pillsbury L, editors. Nutrition and Traumatic Brain Injury: Improving Acute and Subacute Health Outcomes in Military Personnel. Washington (DC): National Academies Press (US); 2011. 8, Branched-Chain Amino Acids. Available from: https://www.ncbi.nlm.nih.gov/books/NBK209312/
2. Neinast M, Murashige D, Arany Z. Branched Chain Amino Acids. Annu Rev Physiol. 2019 Feb 10;81:139-164. doi: 10.1146/annurev-physiol-020518-114455. Epub 2018 Nov 28. PMID: 30485760; PMCID: PMC6536377.
3. Anthony JC, Yoshizawa F, Anthony TG, Vary TC, Jefferson LS, Kimball SR. Leucine stimulates translation initiation in skeletal muscle of postabsorptive rats via a rapamycin-sensitive pathway. J Nutr. 2000 Oct;130(10):2413-9. doi: 10.1093/jn/130.10.2413. PMID: 11015466.
4. Matthews DE. Observations of branched-chain amino acid administration in humans. J Nutr. 2005 Jun;135(6 Suppl):1580S-4S. doi: 10.1093/jn/135.6.1580S. PMID: 15930473; PMCID: PMC2268017.
5. Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? J Int Soc Sports Nutr. 2017 Aug 22;14:30. doi: 10.1186/s12970-017-0184-9. PMID: 28852372; PMCID: PMC5568273.
6. Blackburn PR, Gass JM, Vairo FPE, et al. Maple syrup urine disease: Mechanisms and management. Appl Clin Genet. 2017 Sep 6;10:57-66. doi:10.2147/TACG.S125962
7. Genetics Home Reference. Maple syrup urine disease. U.S. National Library of Medicine.
8. Poortmans JR, Dellalieux O. Do regular high protein diets have potential health risks on kidney function in athletes? Int J Sport Nutr Exerc Metab. 2000;10(1):28-38.
9. To CY, Freeman M, Van Winkle LJ. Consumption of a Branched-Chain Amino Acid (BCAA) during Days 2-10 of Pregnancy Causes Abnormal Fetal and Placental Growth: Implications for BCAA Supplementation in Humans. Int J Environ Res Public Health. 2020 Apr 3;17(7):2445. doi: 10.3390/ijerph17072445. PMID: 32260232; PMCID: PMC7178017.
10. Li N, Li J, Wang H, Liu J, Li W, Yang K, Huo X, Leng J, Yu Z, Hu G, Fang Z, Yang X. Branched-Chain Amino Acids and Their Interactions With Lipid Metabolites for Increased Risk of Gestational Diabetes. J Clin Endocrinol Metab. 2022 Jun 16;107(7):e3058-e3065. doi: 10.1210/clinem/dgac141. PMID: 35271718; PMCID: PMC9891107.
11. AbuMoh’d MF, Matalqah L, Al-Abdulla Z. Effects of Oral Branched-Chain Amino Acids (BCAAs) Intake on Muscular and Central Fatigue During an Incremental Exercise. J Hum Kinet. 2020 Mar 31;72:69-78. doi: 10.2478/hukin-2019-0099. PMID: 32269649; PMCID: PMC7126259.