Amino Acid Supplements

Amino acids are the building blocks of protein, and some of them are also used in forming neurotransmitters. In practice the products here fall into two groups. Some are commonly used within sports nutrition — glutamine, L-carnitine, L-citrulline and L-arginine. Others are commonly used outside any training context — L-theanine, glycine, L-tyrosine, taurine and GABA. The collection also includes close derivatives such as NAC, an acetylated form of the amino acid cysteine, along with 5-HTP and TMG. Available as capsules, tablets and powders from NOW, Nutricost and other brands. Related: sports nutrition, sleep, stress & mood, and brain & memory.