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Branched Chain Amino Acids vs Essential Amino Acids

Branched Chain Amino Acids vs Essential Amino Acids

For years the dietary supplementation industry has profited from the common individuals lack of knowledge, bombarding customers and merchants with technical jargon that serves little purpose other than to leer one into a false sense of being educated. From ketones, to fat burners and a plethora of other so called “fat loss essentials” none have been quite as fruitful to the industry as Branched Chain Amino Acids (BCAA’s).


So what are they?

BCAA’s, formally known as Branched Chain Amino Acids, consist of Leucine, isoleucine and valine. These amino acids are three out of the nine essential amino acids not endogenously produced by the body, thus in order to elicit an “anabolic” response, companies have pushed the oral intake of this supplement. While it has been suggested that leucine is a precursor to muscle protein synthesis (the process In which the body produces protein in order to repair tissue damaged by exercise), there have been zero direct studies resulting in a positive correlation between the oral supplementation of a BCAA product and an increase in MPS.

A journal produced in 2017 by the International Society of Sports Nutrition stated:

“An extensive search of the literature has revealed no studies in human subjects in which the response of muscle protein synthesis to orally-ingested BCAAs alone was quantified, and only two studies in which the effect of intravenously infused BCAAs alone was assessed. Both of these intravenous infusion studies found that BCAAs decreased muscle protein synthesis as well as protein breakdown, meaning a decrease in muscle protein turnover. The catabolic state in which the rate of muscle protein breakdown exceeded the rate of muscle protein synthesis persisted during BCAA infusion. We conclude that the claim that consumption of dietary BCAAs stimulates muscle protein synthesis or produces an anabolic response in human subjects is unwarranted.”

Having said this, there are many studies suggesting a link between the dietary supplementation of leucine to an increase in MPS, however this is yet to proven or falsified. The suggestion that BCAA supplementation links positively to MPS is suggested when leucine is dosed at roughly 75% of the total BCAA make up.



The proverbial new kid on the block in recent years, brewing contempt amongst fitness gurus, professionals and amateurs alike. The industry has brought out yet another amino acid supplement, so what is the difference?

EAA stands for Essential Amino Acid and yet again, these are not produced endogenously by the body so the gap in the market left by BCAA’s has now been filled. These supplements typically consist of 9 amino acids:

  • Isoleucine
  • Leucine
  • Histadine
  • Tryptophan
  • Lysine
  • Methionine
  • Phenylalinine
  • Valine
  • Threonine

The idea of having a product that allows for a full essential amino acid profile in one serving is the main selling point for this product. However, surely that would prove that using a BCAA product is in fact redundant?


Do you need BCAAs/EAAs?

There are many studies to suggest the necessity for BCAA/EAA supplementation throughout all forms of exercise, however correlations have been moderate to low when considering the benefits of this product. It is also important to consider that these studies are all undertaken using clinical dosages of pure product, this may not be the case for your over the counter product. Having a subjective approach to testing as opposed to group studies may prove fruitful as this could relate effectiveness to individual and personal factors e.g. sleep, diet, recovery capabilities etc.

In order for you to truly understand whether or not BCAA/EAA is going to benefit you or your client, it is important to carefully monitor limiting factors such as sleep, diet and training intensity, ensuring these stay as consistent as possible and monitoring the supplementation over a set time will provide somewhat of an individual study more subjective to you or your client.


Special considerations

In some instances, the supplementation of a BCAA/EAA product may be beneficial, the main consideration being diet. Those who have adopted a vegan/vegetarian diet will not be able to retrieve a full amino acid profile from the food sources they have at their disposal. Seeing as the majority of dietary protein comes from meat sources/ animal products e.g. eggs, chicken, beef and fish etc. These foods are known as being “complete” proteins as they contain most, if not all essential amino acids the body requires from external sources. Plant sources of protein e.g. nuts, pulses and lentils etc are known as “incomplete” proteins as they contain few of the essential amino acids required by the body. For people adopting these diets, along with food specific allergies/ intolerances e.g. dairy, eggs, fish etc, it may be useful to supplement a BCAA/ EAA product in order to get a complete amino acid profile in your diet.



In conclusion, due to inconclusive research/ limited supporting data, I feel BCAA/ EAA supplementation is not necessary for the everyday gym goer or client, provided there are no limiting factors or specific dietary requirements, I feel it would be more beneficial to aim for a varied diet with multiple protein sources to achieve one’s full amino acid profile, (this may also prove more cost efficient).

If you enjoyed this article you may enjoy our article on Creatine: Improving Your Strength and Performance.

Tireoghain O’Neill Fitbook Writer


By Tireoghain O’Neill





Wolfe, RR, (2017). Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?,

 (Date accessed: 19/09/20) 

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