L-Phenylalanine jẹ amino acid pataki ati pe o jẹ iṣaju ti amino acid tyrosine.Ara ko le ṣe phenylanie ṣugbọn o nilo phenylalanie lati ṣe agbejade awọn ọlọjẹ.Nitorinaa, eniyan nilo lati gba phenylanie lati ounjẹ.Awọn fọọmu phenylalanie mẹta ni a rii ninu ẹda: D-phenylalanine, L-phenylalanine, ati DL-phenylalanine.Lara awọn fọọmu mẹta wọnyi, L-phenylalanine jẹ fọọmu adayeba ti a rii ni ọpọlọpọ awọn ounjẹ ti o ni awọn ọlọjẹ ninu, pẹlu eran malu, adie, ẹran ẹlẹdẹ, ẹja, wara, wara, ẹyin, awọn warankasi, awọn ọja soyi, ati awọn eso ati awọn irugbin kan.