• Types of Amino Acids

The Types of Amino Acids (and how to choose between them)

There’s a lot of talk in nutrition and fitness circles about amino acids, via foods and supplementation. Many people aren’t sure what amino acids are, exactly, so this article is aimed at clearing up that confusion, and digging a bit deeper into 5 common types of amino acids that you need, and how to choose between them.

What are Amino Acids?

Amino acids are the building blocks of protein, to put it simply. Protein is necessary to our survival, as it plays a critical role in everything from acting as the raw material for our tendons, skin, muscles and organs to making hormones and neurotransmitters. Without protein, we would cease to exist.

Amino acids are smaller molecules that are linked together to form proteins (like a row of beads). These links form long chains, which connect together to form shapes. The human body produces certain amino acids on its own, and others must be obtained from food sources. This is why they are called essential amino acids.

Amino acids are the building blocks of protein

Optimally, your food sources of protein not only contains some, but all essential amino acids (of which there are nine) in the correct ratios for us to be able to most effectively absorb and assimilate them. This is why protein quality really matters, and is basically what is meant when the quality of a protein is referred to.

It’s important to know that animal protein sources almost always offer all essential amino acids in the correct ratios, which makes getting adequate dietary protein much easier than if you follow a vegetarian (and even more-so) vegan diet.

Without further ado, read on to learn about 5 important amino acids, which foods you can get them from, and how to choose between them, in the case of supplementation. As with any supplement, always discuss proper usage and dosage with your healthcare provider.

5 Types of Amino Acids


You’ve probably heard of this one, as it’s become a popular supplement for supporting insomnia and mood. 5-HTP is a compound that is a precursor to serotonin, which is one of the primary neurotransmitters responsible for feelings of happiness. Without it, depression can result.

While 5-HTP can be (potentially) extremely useful in supporting depression, anxiety and insomnia, it can be dangerous when taken alongside an SSRI and other anti-depressant medications. Interestingly, studies show that can also take it alongside a meal, as it works to increase satiety (feelings of fullness), so might be useful for weight loss, as well.

You can’t get 5-HTP from foods, but the amino acid, tryptophan, is what helps your body form 5-HTP. This is found in pumpkin, turkey, chicken, sunflower seeds, milk and seaweed.


L-arginine is an essential amino acid that is often taken as a supplement by athletes, as it supports blood flow and the production of nitric oxide (NO) levels.

Nitric Oxide (NO) is a simple molecule with two atoms, nitrogen and oxygen. It serves many essential functions in the body, and has becoming the secret weapon of body- builders and athletes.

In fact, NO plays such a key role that it was awarded ‘molecule of the year’ by Science Magazine in 1992, and the 1998 Nobel prize in medicine was given to the discovery that NO is a signaling molecule in the cardiovascular system.

L-arginine is also especially important for supporting chronic illnesses like type 2 diabetes and high blood pressure.


This amino acid can be produced by the body, but should be obtained from food, as well. It is well known for its unique anti-aging effects, and also works to support fat-burning and increase alertness. Lesser known benefits of L-carnitine are its benefits for increased insulin sensitivity, which can make it a great supplement for diabetics, in some cases.

Red meat is the best source of this amino acid, along with seafood and dairy.


L-glutamine is known as a conditionally essential amino acid, meaning that the body can usually produce enough, but during periods of extreme stress will need more from food sources. It is usually used as a supplement only by those who are deficient, such as vegans and vegetarians. While not backed by solid research, anecdotal evidence points to this amino acid also lessening sugar cravings.

Interestingly, glutamine works effectively to support digestive and immune health. The cells of these systems use glutamine as their preferred fuel source (over glucose), and has also been shown to play a role in cancer support and wound healing after an injury.

Whey and casein proteins are excellent sources of glutamine (the proteins found in dairy).


Lysine is one of the essential amino acids, and is often paired with vitamin C as a supplement. Research shows that taking lysine works to reduce the symptoms of herpes simplex infection, which is the main reason you would supplement with this amino acid.

Other Amino Acids

While the five amino acids discussed above are of particular importance because many people use them for supplementation, you should know that the essential amino acids include isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine and arginine. The ten non-essential amino acids include alanine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, proline, serin and tyrosine.

The words “essential” and “non-essential” does not speak to one group being more important than the other. The body’s ability to produce sufficient amounts of non-essential amino acids depends on our nutrient stores and overall health (among other factors).

If you eat a whole foods diet with plenty of high quality animal products (organic, pasture raised and/or grass-fed red meat, poultry, seafood and dairy), you probably don’t need to consider supplementing with amino acids unless you are an athlete (or your doctor recommends doing so). If you are a vegetarian or vegan, you are more likely to be deficient in certain amino acids, and supplementation could be important for your health.

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