Nutricology Pyridoxine P5P (B-6) is a combination of pyridoxine hydrochloride & pyridoxal-5-phosphate (P-5-P, the coenzyme or activated form of B6). As P5P, vitamin B6 is extensively involved in the metabolism of amino acids, lipids & nucleic acids. Supplementation with vitamin B6 as P5P can be helpful for those unable to produce it efficiently from pyridoxine in the liver.