What are the key amino acids needed for muscle growth?

Posted by Dayne Hudson in Muscle Building

Estimated reading time: 5mins

What are the key amino acids needed for muscle growth?

Amino acids for muscle growth

In nutrition, we classify amino acids as either essential or non-essential.

So, let's start with the essential amino acids; they are simply the amino acids we cannot make in our body, so we have to eat them.

Whilst our bodies are pretty amazing, they lack the metabolic pathways required to make this happen.

This is compared to something like carbohydrates, which we technically don't have to eat, because our bodies can create the glucose from within the body for energy. This fancy process is called gluconeogenesis, and obviously happens when we're not eating enough carbs to supply our bodies with glucose.

Anyway, there are nine essential amino acids:

  • Phenylalanine
  • Valine
  • Tryptophan
  • Threonine
  • Isoleucine
  • Methionine
  • Histidine
  • Leucine
  • Lysine

Don't worry, you won't be marked on all these essential amino acids in a looming test. But if you wanna impress your friends, the mnemonic PVT TIM HaLL ("private Tim Hall") is commonly relied upon to remember them all!

And eating them all in one go is easy, because you'll find them all (usually) in animal products. Foods that contain all nine of these essential amino acids are called complete sources of protein.

The essential amino acids are also available from incomplete proteins, which are usually plant-based foods, but just not in a dosage that's high enough.

Great, so now you know all about PVT TIM HaLL and essential amino acids.

Branched-chain amino acids

And hiding within the essential amino acids are the branched-chain amino acids, which I'm sure you've heard about many times. They are:

  • Leucine
  • Isoleucine
  • Valine

Also called BCAAs for short, they get a lot of attention because they are the main amino acids utilised in your muscle.

Now we've got non-essential amino acids; the ones our bodies CAN produce without needing to be fed them. They are:

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

So now we've gone through all twenty amino acids together.

Now we're ready to see which ones you need for muscle growth.

Eggs are also a complete protein source
Eggs are also a complete protein source

Amino acids for muscle growth

Here's what we do know: leucine is one of the keys that unlocks the door to muscle growth.

And you'll remember we worked out that leucine is one of the three BCAAs, and of course, an essential amino acid.

And BCAAs alone DO allow for muscle growth, but nowhere near as successfully as other strategies.

For example, this study concluded that taking BCAAs alone without taking the other essential amino acids, allowed for a 22% greater muscle growth response after resistance training compared to nothing at all.

Yep, well that's something at least. We know that works.

But then, the same researchers put the BCAAs with the essential amino acids -- our friend PVT TIM HaLL we just learned about.

And let's just say Timmy boy stormed the battlefield of muscle growth, and should have been awarded for his honour and accomplishments!

When the essential amino acids WERE NOT present, the "muscle myofibrillar protein synthesis was approximately 50% less."

50 per cent less!

So, you need ALL essential amino acids for the best muscle growth results: essential amino acids are at least 50% MORE EFFECTIVE at building muscle than BCAA's in isolation.

And remember, you can get all your essential amino acids them from:

  • Whey protein
  • Animal food products
  • Plant food products (just not quite in a high enough dose, and sometimes with a few missing. This is why vegans rely quite heavily on supplements for all essential amino acids).
Bulk Nutrients has you covered with all essential amino acids in their whey protein powder range.
Bulk Nutrients has you covered with all essential amino acids in their whey protein powder range.

So that's it

There are 9 essential amino acids (and within those the three BCAAs) and 11 non essential amino acids; 20 in total. Leucine, one of the three BCAAs and an essential amino acid, is very important for muscle growth. However, it can't carry the muscle growth show on its own. For optimal muscle growth, we need all essential amino acids, which we can get from complete sources of protein: whey, or animal products like meat, fish, and dairy. We need to focus on complete sources of protein for optimal muscle growth.


  1. Lopez MJ, Mohiuddin SS. Biochemistry, Essential Amino Acids. 2021 Mar 26. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan–. PMID: 32496725.
  2. Melkonian EA, Asuka E, Schury MP. Physiology, Gluconeogenesis. 2021 May 9. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan–. PMID: 31082163.
  3. Platell C, Kong SE, McCauley R, Hall JC. Branched-chain amino acids. J Gastroenterol Hepatol. 2000 Jul;15(7):706-17. doi: 10.1046/j.1440-1746.2000.02205.x. PMID: 10937674.
  4. Layne E. Norton, Donald K. Layman, Leucine Regulates Translation Initiation of Protein Synthesis in Skeletal Muscle after Exercise, The Journal of Nutrition, Volume 136, Issue 2, February 2006, Pages 533S–537S.
  5. Jackman SR, Witard OC, Philp A, Wallis GA, Baar K, Tipton KD. Branched-Chain Amino Acid Ingestion Stimulates Muscle Myofibrillar Protein Synthesis following Resistance Exercise in Humans. Front Physiol. 2017 Jun 7;8:390. doi: 10.3389/fphys.2017.00390. PMID: 28638350; PMCID: PMC5461297.
  6. Hoffman JR, Falvo MJ. Protein - Which is Best? J Sports Sci Med. 2004 Sep 1;3(3):118-30. PMID: 24482589; PMCID: PMC3905294.
  7. Images from unsplash.com 1, 2.

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