As nutritional supplement,L-phenylalanine can be viewed as a benzyl group substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of alanine.
ໃນຖານະທີ່ເປັນສານອາຫານເສີມ, L-phenylalanine ສາມາດເບິ່ງໄດ້ວ່າກຸ່ມ benzyl ທົດແທນ ສໍາ ລັບກຸ່ມ alanine ຂອງກຸ່ມ methyl, ຫຼືກຸ່ມ phenyl ແທນທີ່ຈະເປັນ hydrogen hydrogen ຂອງ alanine.