What are amino acids?

Amino acids are organic compounds that form the building blocks of proteins in your body. These proteins make up many of your tissues, enzymes, hormones and immune components.

Your body uses twenty standard amino acids, each with a unique structure and role. Nine are classified as essential amino acids. Your body cannot produce these, so you need to get them from your diet.

The remaining eleven are non-essential amino acids. This does not mean they are unimportant. Your body can produce them from other compounds when it has the necessary nutrients.

Why amino acids are fundamental to health

Amino acids play many roles in your body beyond building and maintaining muscle. They are needed to produce digestive enzymes and neurotransmitters such as serotonin, dopamine and GABA.

They also help create immune proteins, including antibodies and cytokines. Amino acids support your body’s natural detoxification pathways and hormone production. They also help maintain healthy hair, skin, nails and connective tissue.

Having a regular supply of amino acids helps your body function, repair and adapt.

Branched-chain amino acids (BCAAs) include leucine, isoleucine, and valine. They have specific roles in muscle protein synthesis and recovery. Leucine in particular, helps signal the pathways involved in muscle protein synthesis. Getting enough leucine can support muscle maintenance or development. This can be especially relevant if you lead an active lifestyle or during periods of increased physical demand.

Dietary sources and requirements

A varied diet with good quality protein sources will generally provide all the essential amino acids your body needs. Complete protein sources contain all nine essential amino acids in adequate amounts. These include meat, fish, eggs and dairy products.

You can also get all the essential amino acids from a plant based diet. You may need to include a wider variety of protein sources. Most individual plant proteins contain lower levels of one or more essential amino acids.

Combining legumes with grains can provide a complementary amino acid profile. This includes combinations such as beans with rice or lentils with whole grains.

Amino acid supplementation

Amino acid supplements are available as essential amino acid (EAA) blends, branched-chain amino acid (BCAA) formulas or individual amino acids. These include L glutamine for digestive support, L tryptophan for sleep and mood, and L arginine for cardiovascular support.

You can explore these amino acids in more detail on their individual pages within this guide. Supplementation can be useful if you have higher protein requirements. It may also suit you if your diet does not provide optimal levels of all amino acids.