Methionine is an amino acid found in many proteins, including the proteins in foods and those found in the tissues and organs of your body.

In addition to being a building block for proteins, it has several other unique features. One of these is its ability to be converted into important sulfur-containing molecules.

Sulfur-containing molecules have a variety of functions, including the protection of your tissues, modifying your DNA, and maintaining the proper functioning of your cells.

These important molecules must be made from amino acids that contain sulfur. Of the amino acids used to make proteins in the body, only methionine and cysteine contain sulfur.

Although your body can produce the amino acid cysteine on its own, methionine must come from your diet.

Additionally, methionine plays a critical role in starting the process of making new proteins inside your cells, something that is continuously occurring as older proteins break down.

Methionine starts the process of producing new proteins in your muscles after an exercise session that damages them.