Amino acids are the building blocks of proteins and are essential for the growth, repair, and maintenance of the body's tissues. As an ingredient in skincare products, amino acids can provide numerous benefits for the skin. "There are 20 amino acids, 11 of which are considered 'nonessential' and nine that are considered 'essential,' yet all are vital for the body’s survival. Nonessential means that the body can make them on its own. Essential amino acids must be obtained through the diet (the body cannot make them on its own)." In other words: amino acids are vital components in making our bodies work, so it stands to reason that they would also be vital in anything happening on a skin level, too. You can only get their benefits from eating certain foods or supplements. Examples of essential amino acids include leucine, isoleucine, phenylalanine, histidine, threonine, lysine, methionine, tryptophan, and valine. They are found in animal meat (beef, poultry, seafood), animal products (dairy, eggs), and certain high-protein plant foods (nuts, legumes, soy products, and beans).