Why gelatinis an incomplete protein?

Gelatin is considered an incomplete protein because it lacks certain essential amino acids that the body cannot synthesize on its own. Specifically, it is low in tryptophan and lacks several other essential amino acids, such as isoleucine and leucine. While gelatin can provide some amino acids, it does not offer a complete profile necessary for supporting all bodily functions. As a result, it is often recommended to combine gelatin with other protein sources to achieve a balanced amino acid intake.