High-Dose Vitamin B5 (Pantothenic Acid) for Acne: The Leung Hypothesis

The use of pantothenic acid (Vitamin B5) at gram-scale oral doses for acne vulgaris traces to a 1995 paper by Lit-Hung Leung in the Journal of Orthomolecular Medicine. Leung proposed that sebum overproduction in acne reflects an inadequate supply of Coenzyme A (CoA), which is required both for fatty acid synthesis and for fatty acid beta-oxidation. When CoA is limiting, the body prioritizes synthesis over breakdown, leading to sebum accumulation in the pilosebaceous unit. Since pantothenic acid is the rate-limiting precursor to CoA, megadose supplementation should restore the balance. Leung's open-label trial gave 100 Chinese patients 10 grams oral B5 daily plus a 20% topical B5 cream and reported near-complete clearance over four to eight weeks. The methodology was weak (no placebo arm, no blinding, ethnically homogeneous cohort) but the result was striking enough to circulate. A 2014 double-blind randomized controlled trial by Yang and colleagues with 41 participants tested 2.2 grams of pantothenic acid per day for 12 weeks. The active arm showed roughly 68% greater lesion reduction versus placebo, with no serious adverse events. This is one of the few placebo-controlled trials of any acne supplement. Safety: pantothenic acid has no established Tolerable Upper Intake Level. Even at 10 grams/day, the most common side effects reported are loose stools and mild flushing. There are no reports of organ toxicity, which is unusual for a vitamin at 5,000x the RDA of 5mg. Water-soluble excretion explains much of the tolerance. The mechanism remains debated and the trial base is small, but B5 megadosing is one of the few biohacker-popular acne interventions with both a plausible mechanism and a positive RCT.