The most popular amino acid supplements are perhaps BCAA, EAA and glutamine. However, several other amino acids enjoy popular appeal in the fitness and bodybuilding markets. Citrulline is used to boost levels of nitric oxide in the blood. This can lead to more noticeable muscle pumps, while also reducing soreness when lifting weights. L-carnitine and the related acetyl-L-carnitine (ALCAR) are said to raise alertness and reduce fatigue – which is perhaps why they are found in many pre-workout formulas. Other amino acids found in standalone form include lysine – an essential amino acid thought to promote wound healing, lower anxiety and even reduce cold sores.