What Are BCAAs? Uses, Benefits, and Side Effects

BCAAs may be the key ingredient in your diet if you aim to increase muscle mass, enhance your fitness, and improve your overall health.

Sarah Zimmer, PT, DPT
— Signos
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Updated by

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Science-based and reviewed

May 17, 2024
September 25, 2023
— Updated:
September 26, 2023

Table of Contents

Amino acids are life's building blocks, with 20 amino acids composing all of the proteins throughout our body. Nine of the 20 are considered essential amino acids (versus “non-essential”). These amino acids are named "essential" because our bodies cannot produce them independently; thus, they must be obtained from our diets. They play a fundamental role in various physiological processes, influencing everything from muscle growth to hair growth to energy production. 

Three essential amino acids are chemically structured to form the Branched-Chain Amino Acids (BCAAs). BCAAs have garnered significant attention in recent years as a popular dietary supplement among athletes, fitness enthusiasts, and individuals seeking to optimize their overall health. 

In this article, we will explore the many benefits of BCAAs, their main uses in various aspects of health and fitness, and potential side effects that individuals should be aware of and those who should avoid taking them. Whether you're an athlete aiming to enhance your performance, a fitness enthusiast looking to build muscle, or simply someone interested in understanding the significance of essential amino acids, this article will provide you with the knowledge you need to make informed choices about incorporating BCAAs into a balanced healthy diet while targeting your fitness and health goals. 


What Are BCAAs and What Do They Do? 

Branched-Chain Amino Acids (BCAAs) are a group of three essential amino acids: leucine, isoleucine, and valine.1  What makes BCAAs unique is their branched chemical structure, which differentiates them from other amino acids. This structure allows BCAAs to be metabolized primarily in skeletal muscle rather than the liver, making them readily available for energy production and muscle protein synthesis while reducing the workload on your liver. 

Each of the three components of BCAAs has its role within the goal of energy production and muscle protein synthesis. Leucine is often considered the most important BCAA, as it helps stimulate the creation of new muscle tissue and serves as an energy source during prolonged exercise bouts. Isoleucine helps regulate blood sugar levels, promotes glucose uptake into cells, and contributes to the production of hemoglobin, which is vital for oxygen transport in the blood. Lastly, valine plays a crucial role in energy production and tissue repair. It can be converted into glucose for energy during exercise, contributes to muscle protein synthesis with other amino acids, and is involved with the balance of nitrogen levels, which is important for building proteins. 

Proteins are the backbone of the cells that make up muscles, tissues, and organs throughout the human body. Without them, our bodies would be unable to regrow, repair, and replenish tissues as we strive to maintain good overall health.  

BCAA vs. Protein 

Protein and Branched-Chain Amino Acids (BCAAs) are related components in nutrition and muscle health, but they serve different purposes and have distinct characteristics. The easiest way to differentiate the two is to remember that proteins are a macronutrient made up of many amino acids, while BCAAs are just a portion of the essential amino acids that makes up a protein. 

BCAAs are primarily associated with muscle health and exercise performance by stimulating muscle protein synthesis and reducing exercise fatigue. Proteins are involved in the health and formation of many other tissues besides muscle, including skin, hair, and organs. The protein required to boost muscle growth and performance is thus mostly comprised of BCAAs.  Both BCAAs and proteins are found within a variety of food sources such as meat, fish, dairy, eggs, lentils, tofu, and beans; however, many individuals find benefit in taking a BCAA supplement when their goal is to achieve greater muscle growth and exercise performance specifically. 

In summary, protein offers a broader range of amino acids and serves as a fundamental dietary component, while BCAAs, as a subset of amino acids, are often used for more targeted purposes, particularly in the context of exercise and muscle-specific goals. Most protein powders (i.e., whey protein powder) include BCCAs and many other amino acids, carbohydrates, and vitamins. Again, if you are solely focused on increasing your muscle mass and enhancing your muscle recovery after exercise, finding a BCAA-specific supplement may be more helpful than a generic protein powder. 


8 Benefits of Branched-Chain Amino Acids (BCAAs)

From promoting muscle growth, reducing exercise-induced fatigue, aiding in muscle recovery, and preserving lean mass while dieting, BCAAs have much to offer individuals looking to enhance their physical performance and well-being. These essential amino acids offer a range of advantages, making them a popular dietary supplement choice among athletes, bodybuilders, and those seeking to optimize their overall health. Check out this list of benefits of BCAAs:

  1. Promote muscle growth: BCAAs, especially leucine, are potent triggers for producing new muscle tissue, making them valuable for athletes and individuals looking to build and repair muscle tissue.1,4 
  2. Reduce muscle soreness: After intense workouts,  BCAAs are often used to support muscle recovery by reducing post-exercise soreness and accelerating the repair process.3
  3. Decrease exercise fatigue: BCAAs can decrease the perception of fatigue during exercise by reducing the uptake of tryptophan, an amino acid associated with feelings of tiredness.2
  4. Prevent muscle injuries: BCAAs can be used as an energy source during prolonged physical activity, helping to preserve muscle glycogen and reduce the risk of muscle breakdown.3
  5. May help people with liver diseases: BCAAs help people with liver disease because they can bypass the liver's usual metabolic pathways and provide an alternative energy source for the body, reducing the workload on the liver. They may also improve liver function by promoting the synthesis of albumin, a crucial protein in maintaining blood volume and preventing complications associated with liver disease.8
  6. Maintain Lean Muscle: During periods of calorie restriction or intense training, BCAAs can help prevent the breakdown of lean muscle mass, making them valuable for weight management and overall body composition.4
  7. Enhanced Fat Oxidation: BCAAs can improve the body's ability to burn fat for energy, especially during endurance activities like long-distance running or cycling. This helps spare muscle glycogen and reduces the risk of muscle breakdown.9
  8. Improved Immune Function: Intense exercise can temporarily suppress the immune system. BCAAs may help support immune function by reducing exercise-induced inflammation and oxidative stress, ultimately aiding overall health and recovery.10

It's important to note that while BCAAs offer several benefits, they do not replace a balanced diet. Whole foods provide a wide range of essential nutrients, including BCAAs, and should be the primary source of nutrition. BCAA supplementation is often used to complement a healthy diet and exercise routine, especially for individuals with specific fitness goals or intense training regimens.

Are There Any Risks or Side Effects to BCAAs? 

While Branched-Chain Amino Acids (BCAAs) are generally considered safe for most people when used in moderation, their consumption has potential risks and side effects. It's important to be aware of these considerations, and certain groups, such as pregnant and breastfeeding women, should exercise caution or avoid BCAA supplementation altogether.7 

Some examples of adverse side effects from BCAAs include GI distress, an imbalance of other amino acid levels and protein synthesis, liver and kidney dysfunction, and poor glucose metabolism.5 It is important to understand appropriate dosage levels and stay within this range to reduce the above potential side effects. 

In addition, BCAAs can interfere with certain medications, especially ones that help control blood sugar levels. This includes medications like insulin or oral hypoglycemic drugs. Other medications that interfere with BCAA include Levodopa for Parkinson’s disease, anti-epileptic drugs (i.e., valproate), or medications that contain other amino acids and amino acid derivatives. 

It's crucial to remember that individual responses to BCAA supplementation and medication interactions can vary, and not everyone will experience adverse effects. However, anyone taking medication and considering BCAA supplementation should seek guidance from a healthcare professional to assess potential interactions and make informed decisions about their supplement regimen. 

Is It Good to Take BCAA Everyday?

Taking BCAAs daily is generally considered safe when used in moderation and following recommended dosages. However, for individuals with a typical, sedentary lifestyle and a balanced diet, daily BCAA supplementation may not be necessary, and it's essential to use them in moderation while prioritizing whole-food sources of essential nutrients. 

Research studies have found daily dosages of 10-20g/day and up to 60g/day to be a safe and effective dosage with minimal side effects.5  Make sure to consult a health professional to assess if and how much BCAAs are safe to consume daily for your specific needs and goals. 

7 Foods High in BCAAs 

BCAAs are naturally present in a wide variety of protein-rich foods, and incorporating these foods into your diet can help you meet your BCAA needs. Here is a list of foods that are high in BCAAs

  • Meat, poultry, and fish: Lean cuts of red meat and skinless poultry like chicken or turkey are great health options if you choose animal sources of BCAAs. Fish are also a great animal source of BCAAs, with salmon, tuna, and trout being amongst the highest in BCAAs. 
  • Eggs: The egg white and egg yolk contain a high source of BCAAs. Eating the whole egg allows for a complete protein containing all other essential amino acids. 
  • Dairy products: Finding dairy products with high protein concentrations will ensure you get BCAAs (i.e., Greek yogurt and cottage cheese). All types of milk contain BCAAs, but skim milk has the most BCAA per calorie!
  • Whey Protein: Whey protein supplements are derived from milk and are particularly high in BCAAs. They are a convenient way to boost your BCAA intake, especially for athletes and fitness enthusiasts.
  • Nuts and seeds: Of all the available nuts and seeds, almonds, walnuts and sunflower seeds contain the highest amounts of protein and BCAAs specifically.6 
  • Soy products: Tofu and tempeh are great plant-based options for obtaining protein and BCAAs as they are both derived from the soybean.
  • Legumes, including beans, peas, and lentils: Another great plant-based option is choosing legumes or beans to provide sufficient amounts of protein and BCAAs. Try adding lentils or chickpeas into a stew or adding it to a stirfry with rice for a well-balanced meal. 

When incorporating these foods into your diet, it's essential to maintain a balanced and varied approach to ensure you receive a wide spectrum of nutrients. Depending on your dietary preferences and restrictions, you can choose from animal and plant-based sources to meet your BCAA needs.

Learn More About How to Achieve Better Health Through Exercise with Signos’ Expert Advice.

If you have more questions on improving your health, fitness, and nutrition, seek the expert advice of the Signos continuous glucose monitor and Signos team. A continuous glucose monitor (CGM) can give you the insights to make smarter nutrition and exercise choices. The Signos app provides a unique, personalized program to help you lose weight and reach your health goals. Take this quiz to see if Signos is a good fit for you and reach your goals faster than ever before.  


Frequently Asked Questions:

What do BCAAs do for your body?

BCAAs, or Branched-Chain Amino Acids, are pivotal in muscle health and exercise performance. They stimulate muscle protein synthesis, aiding in muscle repair and growth while reducing the perception of fatigue during physical activity, enhancing endurance, and supporting overall muscle recovery.

Is it good to take BCAA every day?

Taking BCAAs daily can benefit individuals with specific fitness goals, such as athletes and those engaged in regular, intense exercise, as they can help support muscle recovery and performance. However, for individuals with a typical, sedentary lifestyle and a balanced diet, daily BCAA supplementation may not be necessary, and it's essential to use them in moderation while prioritizing whole-food sources of essential nutrients. 

Does BCAA help you lose belly fat?

BCAAs alone are not a direct solution for losing belly fat. However, when combined with a balanced diet and regular exercise, BCAAs may help support weight loss by preserving lean muscle mass during calorie restriction, which can contribute to a healthier body composition and reduced abdominal fat.

Is BCAA a creatine?

No, BCAAs and creatine are not the same. BCAAs are essential amino acids that play a role in muscle protein synthesis and exercise performance, while creatine is a compound that helps produce energy during short bursts of intense activity. Simply put, creatine is a direct energy source during high-intensity, short bursts of exercise, whereas BCAAs are proteins that help with muscle growth and recovery.  

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Topics discussed in this article:


  1. Shimomura, Y., Yamamoto, Y., Bajotto, G., Sato, J., Murakami, T., Shimomura, N., Kobayashi, H., & Mawatari, K. (2006). Nutraceutical effects of branched-chain amino acids on skeletal muscle. The Journal of nutrition, 136(2), 529S–532S. https://doi.org/10.1093/jn/136.2.529S
  2. Cordeiro, L. M. S., Rabelo, P. C. R., Moraes, M. M., Teixeira-Coelho, F., Coimbra, C. C., Wanner, S. P., & Soares, D. D. (2017). Physical exercise-induced fatigue: the role of serotonergic and dopaminergic systems. Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas, 50(12), e6432. https://doi.org/10.1590/1414-431X20176432
  3. Fouré, A., & Bendahan, D. (2017). Is Branched-Chain Amino Acids Supplementation an Efficient Nutritional Strategy to Alleviate Skeletal Muscle Damage? A Systematic Review. Nutrients, 9(10), 1047. https://doi.org/10.3390/nu9101047
  4. Reidy, P. T., Walker, D. K., Dickinson, J. M., Gundermann, D. M., Drummond, M. J., Timmerman, K. L., Fry, C. S., Borack, M. S., Cope, M. B., Mukherjea, R., Jennings, K., Volpi, E., & Rasmussen, B. B. (2013). Protein blend ingestion following resistance exercise promotes human muscle protein synthesis. The Journal of nutrition, 143(4), 410–416. https://doi.org/10.3945/jn.112.168021
  5. Holeček, M. (2022). Side effects of amino acid supplements. Physiological research, 71(1), 29-45.
  6. Tuccinardi, D., Perakakis, N., Farr, O. M., Upadhyay, J., & Mantzoros, C. S. (2021). Branched-Chain Amino Acids in relation to food preferences and insulin resistance in obese subjects consuming walnuts: A cross-over, randomized, double-blind, placebo-controlled inpatient physiology study. Clinical Nutrition, 40(5), 3032-3036.
  7. To, C. Y., Freeman, M., & Van Winkle, L. J. (2020). 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. International Journal of Environmental Research and Public Health, 17(7), 2445.
  8. Park, J. G., Tak, W. Y., Park, S. Y., Kweon, Y. O., Chung, W. J., Jang, B. K., ... & Lee, W. K. (2020). Effects of branched-chain amino acid (BCAA) supplementation on the progression of advanced liver disease: a Korean nationwide, multicenter, prospective, observational, cohort study. Nutrients, 12(5), 1429.
  9. Stoppani, J., Scheett, T. P., Pena, J., Rudolph, C., Charlebois, D., & Charleston, S. C. (2009). Consuming branched-chain amino acid supplement during a resistance training program increases lean mass, muscle strength and fat loss. Journal of the International Society of Sports Nutrition, 6(Suppl 1), P1.
  10. Gu, C., Mao, X., Chen, D., Yu, B., & Yang, Q. (2019). Isoleucine plays an important role for maintaining immune function. Current Protein and Peptide Science, 20(7), 644-651.

About the author

Sarah is a Doctor of Physical Therapy, graduating from the University of Wisconsin Madison in 2017.

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Please note: The Signos team is committed to sharing insightful and actionable health articles that are backed by scientific research, supported by expert reviews, and vetted by experienced health editors. The Signos blog is not intended to diagnose, treat, cure or prevent any disease. If you have or suspect you have a medical problem, promptly contact your professional healthcare provider. Read more about our editorial process and content philosophy here.

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