How many ammino acids are considered to be essential in that the human body cannot synthesize them?

Nine amino acids are considered essential for humans, meaning that they cannot be synthesized by the body and must be obtained from food. These essential amino acids are:

- Histidine

-Isoleucine

-Leucine

-Lysine

-Methionine

-Phenylalanine

-Threonine

-Tryptophan

-Valine