Pyridoxal-5-phosphate (P-5-P)
Synopsis of pyridoxal-5-phosphate (P-5-P)
Pyridoxal-5-phosphate (P-5-P) is the active, coenzyme form of vitamin B6, which also includes pyridoxine, pyridoxal, and pyridoxamine. Unlike these precursor forms, P-5-P does not require conversion in the liver and is immediately bioavailable, making it especially useful for individuals with liver dysfunction, genetic variations, or impaired B6 metabolism. It plays a critical role as a cofactor in over 100 enzymatic reactions, especially those involving amino acid metabolism, neurotransmitter synthesis, and homocysteine regulation.
Key functions of P-5-P include:
- Supporting neurotransmitter production (serotonin, dopamine, GABA)
- Assisting in the synthesis of heme, the oxygen-carrying component of red blood cells
- Converting homocysteine to cysteine, thereby protecting cardiovascular health
- Enhancing immune system function
- Promoting glucose metabolism by assisting in glycogen breakdown
Because it crosses the blood-brain barrier more efficiently than pyridoxine, P-5-P is often used in cases of neurological symptoms, PMS, mood disorders, autism spectrum support, epilepsy adjunct therapy, and metabolic conditions that impair vitamin B6 processing.
Historical Use:
While vitamin B6 was first identified in the 1930s, the active coenzyme form—P-5-P—was more clearly defined in biochemical research by the mid-20th century. For decades, pyridoxine hydrochloride was the standard supplemental form, but emerging research into methylation pathways, genetic SNPs (e.g., MTHFR, ALPL), and functional medicine approaches has highlighted the advantages of using bioactive forms like P-5-P.
Historically, vitamin B6 deficiencies were treated with pyridoxine, but some individuals—especially those with liver disease, alcohol dependence, renal issues, or certain genetic polymorphisms—show poor conversion to P-5-P. This has led to the therapeutic use of P-5-P in conditions such as:
- Peripheral neuropathy
- Carpal tunnel syndrome
- Seizure disorders in infants (pyridoxine-dependent epilepsy)
- Mood dysregulation, including depression and anxiety
- Hormone-related symptoms like PMS and morning sickness
In modern integrative medicine, P-5-P is valued for its efficacy in sensitive populations, its neurological support, and its role in reducing inflammation and oxidative stress linked to dysfunctional methylation and homocysteine elevation. It is typically included in B-complex supplements, mood-support formulas, and neurological health protocols in precisely measured doses to ensure safety and effectiveness.
Pyridoxal-5-phosphate (P-5-P) is used for these health conditions
Alcoholism (Scientific)
Anemia (Scientific)
Anxiety (Scientific)
Anxiety Disorders (Scientific)
Athletic and Exercise Aids (Scientific)
Cardiovascular Disease (Scientific)
Chemotherapy (reducing side effects) (Scientific)
Confusion (Scientific)
pyridoxal-5-phosphate (P-5-P) is used to support these body systems
Blood (Scientific)
Brain (Scientific)
Digestive System (Scientific)
Glandular System (Scientific)
Immune System (Scientific)
Mitochondria (Scientific)
Nerves (Scientific)
Serotonin (Scientific)
Specific Neurotransmitters (Scientific)
