Essential Amino Acids Vs. Non-Essential Amino Acids

Chalk board displaying the difference between essential & non-essential amino acids
Amino acids are the “building blocks” of protein. While there are around 100 total amino acids naturally-occurring, humans only need about 20 of them. Many know amino acids play a vital role in protein synthesis, but they’re also necessary for nutrient storage, neurotransmitter production, energy generation, and nucleotide synthesis. They’re also needed for tissue repair and metabolism maintenance too. But within the robust family of amino acids, there are some that are especially important you could even say they're essential. Ahead, we've got a quick primer on which amino acids you need to optimize performance, maintain health, and grow muscle!

Types of Amino Acids

Amino acids are divided into two categories: essential and non-essential.

Essential Amino Acids

Of the 20 amino acids needed by the human body, nine of them are considered essential. That is, these essential amino acids (EAAs) are those amino acids the body cannot synthesize and therefore must consume them through food or supplementation. These nine essential amino acids must be consumed through the diet (via food or supplementation) to maintain protein synthesis, build muscle, and survive. The nine EAAs are:
  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine
Unlike carbohydrates or fats, the body doesn't store amino acids for use later on. Instead, it's constantly using them to create new proteins, which means you want to provide a steady stream of essential amino acids to keep things running as they should.

Non-Essential Amino Acids

Along with the nine essential amino acids of the human body, there are also 11 nonessential amino acids. These amino acids are termed "non-essential" because the body can create them from other amino acids and nutrients in the body. The 11 non-essential amino acids are:
  • Alanine
  • Arginine
  • Asparagine
  • Aspartate
  • Cysteine
  • Glutamate
  • Glutamine
  • Proline
  • Serine
  • Tyrosine
Within the category of non-essential amino, eight of them are considered "conditionally" essential. The reason they're classified as "conditionally essential" is that under normal circumstances, the body can produce sufficient amounts of these amino acids to perform the variety of functions required of them. However, during times of illness or extreme stress (i.e., weightlifting), the body cannot produce enough to keep up with demand, and that's when consuming food or an amino acid supplement containing the conditionally essential amino acids may be useful.

Sources of Amino Acids

As we stated up, the essential amino acids must be obtained through the diet, which means consuming food in some form or fashion for most people. The best way to ensure you’re getting in the required amounts of amino acids each day is by consuming adequate amounts of protein from a variety of sources. Animal proteins are “complete” proteins in that they contain all nine essential amino acids humans require on a daily basis. Plant proteins (beans, grains, vegetables, etc.) are often missing one or more of the essential amino acids, and are therefore “incomplete” proteins. If you are a vegetarian and looking to get all of your EAAs from only food, you’ll have to do some mixing and matching. For example, eating beans and rice provides the complete amino acid profile you need, as does consuming quinoa. Of course, there’s always vegan protein powders and amino acid supplements if you get in a bind and need to hit your protein numbers on the go.


Amino acids provide the basis for all of your muscle-building aspirations as well as thousands of other functions in the body. Whether you’re an herbivore, carnivore, or omnivore, make sure to eat a diverse diet so the amino acid pool in your body is always fully stocked and your body is primed for the big time.

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