Niacin Does Not Accelerate PCP Elimination: Fact vs. Myth

Niacin (vitamin B3) does not accelerate the elimination of phencyclidine (PCP) from the body. This is a persistent myth with no scientific basis.

PCP Pharmacokinetics

• Primary metabolism: Hepatic oxidation via CYP2B6 and CYP3A4 to inactive metabolites.
• Excretion: Renal elimination of metabolites; <10% excreted unchanged in urine.
• Half-life: 7–46 hours (highly variable); chronic use prolongs detection due to lipid sequestration.
• Influencing factors: Urinary pH (acidification increases clearance), hydration, age, liver function, and body fat percentage.

Niacin's Actual Effects

Niacin causes cutaneous vasodilation ("niacin flush") via prostaglandin-mediated mechanisms. It has no effect on hepatic CYP enzymes, renal tubular secretion, or PCP protein binding. High-dose niacin carries its own risks: hepatotoxicity, glucose intolerance, hyperuricemia, and hypotension.

Clinical Reality

No supplement, detox drink, or regimen reliably "flushes" PCP for drug testing. Tampering with urine samples is detectable. The only reliable way to test negative is abstinence for a period exceeding the drug's detection window (urine: up to 7–14 days chronic use; hair: 90 days).

Individuals concerned about PCP use should seek professional substance use treatment rather than relying on unproven detox methods.