(DL-Phenylalanine) Free Form Amino Acid Dietary Supplement Twinlab DLPA is a 50/50 (equimolar) mixture of D-Phenylalanine and L-Phenylalanine. Twinlab DLPA Capsules are easy to swallow and more bioavailable. Well tolerated by highly allergic individuals. This product is manufactured at our own state-of-the-art facility.