EAAs vs. BCAAs

EAAs vs. BCAAs: What’s the Difference?

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Amino acid supplements have been popular for decades. At the turn of the 21st century, branched-chain amino acids (BCAAs) proliferated and took over the intra-workout and post-workout supplement niches.

Fast forward to now, and you’ll notice essential amino acids (EAAs) are following that same trend—often marketed as being superior to BCAAs.

So, what’s the difference between EAAs and BCAAs? Are EAAs better than BCAAs? Should you be taking EAAs? This article will answer all your questions about these popular amino acid supplements and detail how they impact muscle growth.

Essential Amino Acids vs. Nonessential Amino Acids

Before we dive into the EAAs vs. BCAAs debate, let’s briefly examine the 20 protein-creating amino acids that commonly occur in nature. These 20 amino acids are the veritable “building blocks” of proteins. Since muscle protein is a major constituent of muscle tissue, amino acids play a vital role in muscle building.

Nine of the 20 amino acids necessary for muscle protein synthesis are nutritionally “essential” for humans, meaning we must consume them in the diet or through amino acid supplements.

These nine EAAs include:

  • Histidine
  • Isoleucine (BCAA)
  • Leucine (BCAA)
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine (BCAA)

Three of the nine EAAs are branched-chain amino acids (BCAAs), which are so named due to their characteristic branching structure on a molecular level. Thus, BCAAs are a subgroup of EAAs. We will discuss the difference between the full spectrum of EAAs and the three BCAAs in just a bit.

Now, what about the remaining 11 amino acids that don’t classify as “essential”? Well, they are known as nonessential amino acids (NEAAs) since the body can synthesize them endogenously (a big word for “on its own”) from other molecules, such as glycerol from fat. If you happen to be lacking one (or several) of the NEAAs, your body can get by just fine for a while.

However, don’t misconstrue the above as saying the NEAAs are unnecessary in the diet. Quite the contrary, actually. Your body needs ample NEAAs for vital physiological processes, like creating neurotransmitters, enzymes, and peptide hormones. 

Moreover, your body will break down proteins and use certain amino acids for energy if necessary (not ideal if you’re trying to build muscle). Fortunately, NEAAs are typically abundant in nature, and most protein-rich foods have a high proportion of these amino acids.

Here are the 11 NEAAs:

  • Alanine
  • Arginine
  • Asparagine
  • Aspartic acid
  • Cysteine
  • Glutamic acid
  • Glutamine
  • Glycine
  • Proline
  • Serine
  • Tyrosine

Some of the NEAAs, notably L-alanine, L-glutamine, and L-arginine, are technically conditionally essential amino acids. This means they are a necessary component of the diet during certain stages of development and under adverse physiological stress, such as long bouts of intense strength training. 

Should You Take EAAs?

Essential amino acids, especially BCAAs, aren’t always easy to come by in whole foods, particularly if you follow a vegan diet. Mother Nature decided to make plants less-robust sources of EAAs and BCAAs compared to dairy and animal meat.

If you are on a strict vegan or plant-based diet, supplementing with EAAs or BCAAs may be prudent. However, you’ll want to find a product that provides fermented BCAAs/EAAs—these are vegan-friendly amino acids. If the label doesn’t explicitly state that the amino acids are fermented or vegan, they are likely derived from animal products.

Now, if you’re someone who eats a lot of animal-based protein (e.g., beef, chicken, and dairy), taking an EAA supplement can still prove beneficial for muscle building and recovery. Since the amino acids in EAA supplements are free-form, they are quickly absorbed and rapidly increase muscle protein synthesis (assuming the proper ratio of essential amino acids is included in the formula).

To date, much of the research behind EAAs has taken place in clinical studies of sarcopenia and cachexia—medical conditions associated with muscle wasting. The findings of these studies are consistently promising, showing that modest doses of EAAs stimulate protein synthesis, mitigate muscle protein breakdown, and encourage muscle growth (even in patients on bed rest). 

Technical jargon aside, EAAs enriched with BCAAs catalyze muscle building.

Naturally, essential amino acid supplements are growing in popularity as a pre-, intra-, and post-workout solution for muscle building and increasing strength. But are they better than BCAAs? Let’s see what research has to say about EAAs vs. BCAAs.

Are EAAs Better than BCAAs for Muscle Growth?

To reiterate, BCAAs are a subgroup of three EAAs: L-leucine, L-isoleucine, and L-valine. They are “branched-chain” amino acids due to their distinct chemical structures.

BCAAs have received considerable recognition in the sports supplement realm over the past decade due to their pivotal role in protein synthesis. Research suggests that BCAAs, especially L-leucine, are the “master regulators” of muscle protein synthesis. Studies corroborate that the proportion of L-leucine in a protein source directly affects the magnitude of muscle protein synthesis. In simpler terms: The more L-leucine in a complete protein source, the more muscle protein it creates.

But here’s the kicker…

While BCAAs are critical for initiating protein synthesis, they still need the help of the other six EAAs to create new muscle proteins. Hence, EAAs are taking over as the more applicable supplement for building muscle and promoting athletic performance.

BCAAs certainly have their place as a nutritional supplement, but the current body of evidence makes it pretty clear that all of the essential amino acids are necessary for optimal muscle protein synthesis, not just the BCAAs. If you lack any of the EAAs, protein synthesis will be limited accordingly.

Consider the analogy of making a pumpkin pie recipe from scratch, except you’re short on brown sugar. Is that pie going to taste as sweet and delicious as it normally would with all the ingredients? Of course not.

Another way to look at it: Each team in a game of football is supposed to have 11 players on the field at a time. If a team is missing one or two key players on offense during the game, they won’t be able to execute their plays as effectively.

Muscle protein synthesis is no different. Every EAA is important; they are building blocks that work in concert to create new proteins. As such, the crown has to go to EAAs for muscle growth and recovery from exercise.

Intuitively then, gym-goers are quick to assume that slamming EAAs around the clock leads to “extra” muscle growth. Unfortunately, that’s not how things work, either. The body has an intrinsic “cap” to muscle protein synthesis after ingesting a sufficient amount of EAAs

For example, drinking 20 grams of leucine-rich EAAs won’t lead to more muscle protein being created than drinking three times that amount of EAAs. Maybe a more relatable example is that eating a massive 2-lb porterhouse steak won’t lead to more muscle growth than eating 4 oz of steak. This phenomenon is known as the “muscle-full” effect, and it’s suggested to last upwards of four hours after a meal.

Therefore, if your goal is to maximize muscle building, it’s wise to consume several ample—but not excessive—servings of protein/EAAs over the course of the day. For most people, this translates to about 30 grams of complete protein (e.g., whey protein, chicken breast, eggs) or 10 grams of pure EAAs.

The “muscle-full” phenomenon makes sense if you think about it: If there was no limit to muscle protein synthesis after consuming EAAs/protein, we could build infinite amounts of muscle mass simply by chugging EAAs once per day. The salient takeaway here is that building muscle takes time; no matter how frequently you lift weights, you can’t expedite the process by consuming excessive amounts of EAAs and protein.

When Should You Take EAAs or BCAAs?

Regardless if you take EAAs or BCAAs, these supplements are ideal before, during, and/or after exercise. Many gym-goers will sips on essential amino acids as they go through their workout to support stamina and recovery.

If you eat a wholesome pre-workout meal and start exercising about an hour later, it’s probably best to wait and take EAAs immediately post-workout. If you end up training 2 to 3 hours after eating a protein-rich meal, then drinking BCAAs during your workout can help encourage protein synthesis since you’ll still have plenty of the other essential amino acids to work with from the pre-workout meal.

In most cases, EAAs can supplant the use of BCAAs, but the inverse isn’t necessarily true. For example, it’s unlikely that BCAAs will stimulate protein synthesis to a high degree if you haven’t eaten a protein-rich meal for 6+ hours. In such instances, BCAAs would be relegated to the role of reducing muscle protein breakdown

EAAs, on the other hand, can provide the same anabolic response as complete protein sources, like whey protein. Some research has shown that taking  EAAs after a workout stimulates protein synthesis as effectively as whey protein despite providing the same proportions of essential amino acids.


What’s the Best Ratio of EAAs for Muscle Growth?

Extrapolating from research, the ideal ratio of EAAs for muscle protein synthesis is:

  • Isoleucine: 10%
  • Leucine: 20%
  • Valine: 10%
  • Threonine: 14%
  • Lysine: 15%
  • Methionine: 5%
  • Tryptophan: 5%
  • Histidine: 11%
  • Phenylalanine: 10%

It’s not the end of the world if the ratio in your EAA supplement is slightly different. However, the BCAAs in a 2:1:1 ratio of leucine to isoleucine and valine is crucial. Make sure you find an EAA supplement that provides plenty of L-leucine; having “more than enough” is better than not enough.

Should I Take EAAs or BCAAs While Fasting to Protect Against Muscle Loss?

EAAs would be the more fitting option if you are following an intermittent-fasting regimen. However, be aware that protein synthesis is an energy-consuming process that counteracts fat-burning pathways. Consuming EAAs during a fast will help protect against muscle tissue breakdown, but it will also reduce the use of fat for energy. You have to decide if the trade-off is worth it.

Do I Still Need to Eat Protein if I Take EAAs?

Yes! EAAs are not a replacement for a balanced diet with plenty of protein from whole foods. Use EAAs as a supplement to your diet, not a substitute.

What’s Better for Post-Workout: EAAs or Whey Protein?

This is a question that has no clear-cut answer since it depends on a range of factors. If anything, we can safely say that it’s a draw between EAAs and whey protein—both are great options as post-workout supplements for kickstarting the muscle-repair process. The main difference is that the amino acids in an EAA supplement are not bonded together like they are in whey protein, so the former requires minimal digestion and is absorbed rapidly. However, this doesn’t appear to make much of a difference in the context of building muscle.

What’s the Best EAA Supplement?

Now that you know the differences between EAAs and BCAAs, the next step is finding the right amino acid supplement for your needs. To help make the process easier, be sure to check out our list of the best EAA supplements if you’re on the hunt for a quality EAA formula to replenish you before, during, and after workouts!

Elliot Reimers

Elliot Reimers is a NASM Certified Nutrition Coach (CNC) and M.S. candidate at Michigan State University, where he is studying Molecular Pharmacology and Toxicology. He has been a freelance science writer since 2013, centering on the topics of nutritional science, dietary supplementation, fitness, and exercise physiology. He received his B.S. in Biochemistry from the University of Minnesota and is an inveterate “science nerd” who loves fitness. He is passionate about coaching and educating people about how to live healthier, be smarter about what they put in their bodies, and perform better. In his spare time, you’re most likely to find Elliot hoisting barbells, hiking the mountains of beautiful Colorado, or working on content for Simply Shredded.