2. Methionine
As mentioned earlier, methionine is essential in producing other amino acids such as cysteine. It is classified as an essential amino acid which helps maintain multiple cell functions. Methionine is important for helping organs such as the liver and is used for healing wounds, which is very important in muscle growth. The increased healing it provides is also great for those who want to prevent or recover from hair loss. According to research, taking in methionine orally or by IV seems to be the best method, but it is not to be taken without medical supervision.