The reality, myths and fallacy of BCAA vs. EAA.

BCAAs We have written about the importance and benefits of essential amino acids before. Did you miss the article? Check it out here . So we already know that essential amino acids are better than any superfood or biohack. Today we're going to look at how BCAAs and EAAs differ. And we'll bust a few myths, too.

As we went down the rabbit hole and spent dozens of hours reading amino acid studies to formulate the best amino acid product on the market , we discovered something else very interesting and surprising.

But let's go step by step. To understand the context, we will start a little more broadly.

Branched chain amino acids (BCAAs)

BCAAs (Leucine, Isoleucine, Valine) have a branched chain molecular structure that allows them to bypass the liver after consumption (the so-called first-pass effect) and can thus be rapidly metabolized in muscle tissue [ 1 ], providing a direct fuel source for your muscles . This means that you can rely on BCAAs as a source of energy for your muscles during exercise without much of a digestive or "processing" requirement.

This fact has made BCAA a darling of not only the bodybuilding industry, but also an inexpensive favorite for all athletes looking to boost performance quickly. However….

…there are some big myths about BCAAs and their disadvantages when taken alone.

Most supplement manufacturers know that BCAAs are insanely cheap to produce, especially compared to EAAs. And therefore insanely profitable.

However, their benefits may not be as rosy as they may seem. In some cases, they can even be harmful, as you'll find out in a moment.

Benefits of BCAAs

However, despite their drawbacks, cost, and relative ineffectiveness, BCAAs have been shown in studies to have beneficial effects on a number of performance-related metrics, including:

  • - Prevention of muscle damage caused by exercise
  • - Reduction of post-exercise muscle soreness (DOMS)
  • - Support for regeneration after exercise
  • - Reduction of perceived exertion and mental fatigue during exercise

  • Nevertheless, there are still a lot of half-truths or even myths about BCAA. Here are some reasons to make you a more informed user of essential amino acids. As the icing on the cake, we will also serve you a few suggestions as to whether it makes sense to continue using separate BCAAs.

    Myths and side effects of BCAAs

    Do BCAAs really support muscle protein synthesis and therefore muscle growth?

    For decades, BCAAs were considered the "holy grail" for big muscles and a lean body. While all amino acids contribute to muscle protein synthesis, Leucine is probably the most effective. This is why many people not only in the fitness industry have started taking BCAAs.

    After all, why take all the amino acids when three are all you need? However, this thinking has led many people astray. Why? Because of one aspect of the physiology of the human body…

    Although BCAAs are the most important amino acids that ensure muscle protein synthesis, a 2017 meta-analysis found that almost none of the studies showed that BCAAs alone were responsible for more efficient muscle protein synthesis. [ 2 ] In fact, this meta-analysis discusses two studies that found that BCAAs actually decrease muscle protein synthesis and increase the rate of catabolism (breakdown) of lean tissue!

    So if you have an excess of BCAAs, the body will actually break down its own muscle tissue to free up other essential amino acids, balance BCAA levels and maintain homeostasis.

    Although leucine is able to stimulate muscle protein synthesis in the absence of other amino acids, it must be emphasized that protein synthesis will ultimately be limited by the availability of other essential amino acids .

    The potential muscle loss is reason enough to consider wasting your hard-earned muscle on BCAAs. What do you think?

    And unfortunately there is more. Let's take a look at BCAA side effects together.


    Unfortunate side effects of taking BCAAs alone

    Now you know that isolated BCAAs are less effective for building muscle. But there is also research that points to some potentially harmful side effects of regular high-dose BCAA supplementation.

    BCAAs can deplete vitamin B

    B vitamins - specifically B1, B2, B3, B5 and B6 - are necessary for the breakdown, synthesis and utilization of BCAAs. [ 3 ]

    Thus, taking high doses of BCAAs could deplete your B vitamin stores.

    That's bad news, especially considering that B vitamins are essential for converting food into energy, nervous system function, healthy hair, skin, and nails, DNA synthesis, hormone production, and more.

    BCAAs can lower serotonin levels

    BCAA and the amino acid tryptophan compete for the same carrier system for transport to the brain. [ 4 ]
    By reducing tryptophan uptake in the brain, this is exactly how BCAAs can help stave off fatigue during long-duration workouts. [ 4 ]

    This means that when BCAA concentrations in the body are abnormally high, the brain does not receive as much tryptophan. While that's good news during your workout, it also means you can inadvertently lower your levels of serotonin—the calming, mood-enhancing neurotransmitter—because tryptophan is its precursor.

    So the whole equation is:
    High BCAA intake = low tryptophan absorption = reduced serotonin levels

    Chronically low serotonin can lead to serious neurological imbalances that increase the risk of depression, anxiety, sleep problems, attention deficit disorder, and more. [ 5 ]

    BCAAs may lead to a higher risk of metabolic diseases

    BCAAs are known to influence insulin activity and support glucose uptake by muscles, which ultimately has a positive effect on athletic performance.

    However, when BCAAs are taken in high doses and in isolation from other amino acids, as research shows, BCAAs can actually lead to blood sugar dysregulation, or even insulin resistance, thereby increasing the risk of more serious metabolic diseases such as diabetes.

    Several studies confirm this fact:

    - Adding BCAA to a high-fat diet contributes to the development of insulin resistance and impaired glucose homeostasis. [ 6 ]

    - Higher BCAA levels have a significant association with the future development of diabetes. [ 7 ]

    - Increased fasting circulating BCAA concentrations are associated with increased risk of type 2 diabetes and insulin resistance. [ 8 ]

    BCAAs can lead to overeating and weight gain

    High levels of BCAAs are also associated with obesity. [ 6 ] More recent research shows that high levels of BCAAs can disrupt appetite signaling, leading to overeating and obesity, which then causes metabolic dysfunction.

    Although this is an animal study, in 2019 researchers found that mice given higher levels of BCAAs (200% compared to the control group) experienced hyperphagia – an abnormal state of intense hunger and overeating. The mice thus gained more weight (fat mass) than the control group (in which there was no increase in muscle mass). Additionally, these mice had a 10% shortened overall life span. [ 9 ]

    The researchers concluded that these effects were not due to the high levels of BCAAs, but a result of the body compensating for the amino acid imbalance caused by the BCAAs. In fact, the researchers found that by adding certain essential amino acids back into the mice's diet (specifically tryptophan and threonine), they were able to reverse the effects of BCAAs and significantly reduce hyperphagia.

    What you probably didn't know about EAA?

    Combining all the essential amino acids together (including the three BCAAs mentioned) prevents the potential side effects caused by the amino acid imbalance caused by the excess of BCAAs while providing you with a full spectrum of benefits.

    Remember how we promised something wow at the beginning of the article? We think the time has come to reveal a little secret that not many people know.

    Based on the latest research, it can be said that EAAs are even more effective when they contain a relatively higher ratio of leucine (again in combination with other amino acids, not alone). These essential amino acids enriched with leucine are sometimes referred to as (L)EAAs.

    Why are (L)EAAs even better for muscle and sports recovery?

    The key to (L)EAA's magic, as you now know, is the leucine content, as indicated by the "L".

    Leucine is undoubtedly the most effective amino acid when it comes to muscle building and athletic recovery.

    Mechanically, leucine supports muscle and recovery in a number of ways:

    - It increases the rate of muscle protein synthesis (but as you already know, it does not work effectively in isolation). [ 10 ]

    - Regulates the production of anabolic endocrine hormones. [ 11 ]

    - It stimulates the release of insulin, which increases the absorption of other amino acids and suppresses the breakdown of muscle proteins. [ 12 ]

    - Modulates the mTor pathway (metabolic pathway affecting cell growth and survival) which monitors nutrient availability, cellular energy and oxygen levels and triggers muscle hypertrophy (increase and growth of muscle cells). [ 13 ]


    In no case is it out of place to say that BCAAs are bad at all costs. However, we should keep in mind that BCAAs are not effective for building muscle when taken in doses that are common in most supplements today. On the contrary, they can cause the problems mentioned above.

    But there's no need to completely damn amino acid supplements, because the solution is actually quite simple. Make sure you consume all EAAs that include the appropriate ratio of BCAAs plus other essential amino acids to provide the benefits of the full spectrum of essential amino acids. For example, just like our premium essential amino acids EAA Flow .

    Thanks to the use of essential amino acids, you can experience huge benefits in the field of sports performance, energy, mood, satiety and much more. If you take essential amino acids enriched with leucine, as we have created here at Flow, you can count on more efficient muscle protein synthesis, lean muscle mass growth and sports recovery.

    PS : We were so excited about the final formulation of (L)EAA and their real effect on sports regeneration that we also used this ratio for our comprehensive product Recovery drink for faster muscle mass regeneration, replenishment of depleted glycogen reserves and rehydration of the body to balance the electrolyte balance bodies. In short, comprehensive support for the regeneration of athletes.