P-5-P (B6)
Active coenzyme form of B6. Required for 100+ enzymatic reactions: transamination (amino acid metabolism), neurotransmitter synthesis (serotonin, dopamine, GABA), and homocysteine clearance. P-5-P requires no hepatic conversion - unlike pyridoxine HCl in most supplements.
Mechanism
Pyridoxal-5-phosphate (P-5-P) is the biologically active cofactor form of vitamin B6, serving as a coenzyme for over 100 aminotransferases and decarboxylases. Its functions include: transamination (the metabolic shuffling of amino groups between amino acids); decarboxylation of 5-HTP → serotonin, DOPA → dopamine, and glutamate → GABA; and methylation of homocysteine via cystathionine beta-synthase (in conjunction with B12 and folate).
Most B6 supplements use pyridoxine hydrochloride - the cheapest form, which requires two hepatic enzyme steps to convert to P-5-P. This conversion is rate-limited and can be impaired in individuals with hepatic dysfunction. P-5-P bypasses this entirely.
Key Benefits
- Active form - no hepatic conversion required
- Required for serotonin, dopamine, and GABA synthesis
- Key participant in homocysteine clearance with B12 and folate
- Cofactor for 100+ aminotransferases and decarboxylases
- Supports red blood cell haemoglobin synthesis
P-5-P (B6)
2.8mgPyridoxal-5-phosphate - active coenzyme form
Any time of day with food. P-5-P is the active coenzyme form - no hepatic activation step required, unlike pyridoxine HCl.