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Pyritinol (Pyrithioxine) is a molecule that is, structurally, two Vitamin B6 molecules attached to each other. It is touted to be an anti-hangover pill and a brain booster, with subpar evidence for both claims; it is linked to a moderate amount of avoidable side-effects.

Our evidence-based analysis on pyritinol features 27 unique references to scientific papers.

Research analysis led by and reviewed by the Examine team.
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Research Breakdown on Pyritinol


Pyritinol is a semi-water soluble compound that is constructionally similar to Vitamin B6. Essentially, it is two pyridoxine(B6) molecules mirroring each other, in which they are bond not by their phosphorus side chains but instead a disulfide bridge.[1] It is commonly sold as pyritinol hydrochloride, or pyrithioxine hydrochloride.


It is implicated in recovery and repair of damaged cholinergic neurons[2] and may increase acetylcholine levels[3] and uptake[1] through lipid soluble metabolites.[4] It also increases glucose utilization and cGMP levels in the brain, although more clinically significant in aged subjects.[1]

In vivo, it has been used with some success in treatment of Tourette's[5] dementia[6][7] and general cognitive decline.[8][9][10]

It has been noted that these studies have their validity questioned due to small sample sizes.[11] Most literature has also been published in the 1980s and has not been replicated to a large degree.

3Pyritinol, Inflammation, and the Immune System

Pyritinol can stimulate neutrophil function[12] and cause an increase in neutrophil cGMP levels.

It has been used with moderate success in vivo for reduction of symptoms associated with rheumatoid arthritis.[13]

4Effects on alcohol metabolism and hangovers

Pyritinol is sometimes marketed as an anti-hangover pill through its prostaglandin inhibitory effects which result in a prevention of methanol and formeldehyde induced inflammation.[14] Only one study has been directly recorded, which showed some benefit.[15]

5Safety and Toxicity

Pyritinol has been linked to, and causality established, case study of acute pancreatitis (inflammation of the pancreas), the subject took 600mg daily for 3 months leading up to the initial inflammatory reaction, and then subsequent reactions were induced with minimal dosing.[16][17] It has been linked to causing acute hepatitis (inflammation of the liver) as well in over 5 case studies averaging 400-600mg daily and experiencing jaundice and hepatitis within 2 weeks of starting usage.[18][19] The mechanism of action for pyritinol's hepatotoxicity appears to be due to individual physiology (not applicable to everybody) and cholestatic in nature.[18]

It has historically been linked to drug-induced pemphigus[20] and occupational-contact dermatitis[21] and other topical outbursts have been noted.[22][23][24] A single case of auto-immune hypoglycemia has also been recorded.[25][26]

Most of these side effects are due to pyritinol belonging to a class of sulfhydryl compounds.[27]

Given its usage in Europe for over twenty years[18][16] for medicinal treatment, it is unlikely that these effects manifest themselves in the majority of persons; equally likely is underreporting in the past of pyritinol-induced hepatitis.[18]


  1. ^ a b c Greiner HE, Haase AF, Seyfried CA. Neurochemical studies on the mechanism of action of pyritinol. Pharmacopsychiatry. (1988)
  2. ^ Toledano A, Bentura ML. Pyritinol facilitates the recovery of cortical cholinergic deficits caused by nucleus basalis lesions. J Neural Transm Park Dis Dement Sect. (1994)
  3. ^ Martin KJ, Vyas S. Increase in acetylcholine concentrations in the brain of 'old' rats following treatment with pyrithioxin (Encephabol). Br J Pharmacol. (1987)
  4. ^ Martin KJ, Tucker L, Widdowson L. Effects of some metabolites of pyritinol (Encephabol) on ACH release from brain slices. Pharmacopsychiatry. (1988)
  5. ^ Zykov VP, Begasheva OI. Cognitive disturbances in patients with tics and Tourette's syndrome and their correction with encephabol. Zh Nevrol Psikhiatr Im S S Korsakova. (2003)
  6. ^ Fischhof PK, et al. Therapeutic efficacy of pyritinol in patients with senile dementia of the Alzheimer type (SDAT) and multi-infarct dementia (MID). Neuropsychobiology. (1992)
  7. ^ Cooper AJ, Magnus RV. A placebo-controlled study of pyritinol ('Encephabol') in dementia. Pharmatherapeutica. (1980)
  8. ^ Herrmann WM, Kern U, Röhmel J. On the effects of pyritinol on functional deficits of patients with organic mental disorders. Pharmacopsychiatry. (1986)
  9. ^ Slánská J. Controlled study of the effect of pyritinol in geronto-patients. Act Nerv Super (Praha). (1990)
  10. ^ Gonçalves N. Pyritinol in the ambulatory geriatric patient. A placebo controled combined study. Med Welt. (1979)
  11. ^ Gilbert D. Treatment of children and adolescents with tics and Tourette syndrome. J Child Neurol. (2006)
  12. ^ Elferink JG, de Koster BM. Differential stimulation of neutrophil functions by pyrithioxine. Int J Immunopharmacol. (1993)
  13. ^ Lemmel EM. Comparison of pyritinol and auranofin in the treatment of rheumatoid arthritis. The European Multicentre Study Group. Br J Rheumatol. (1993)
  14. ^ Khan MA, Jensen K, Krogh HJ. Alcohol-induced hangover. A double-blind comparison of pyritinol and placebo in preventing hangover symptoms. Q J Stud Alcohol. (1973)
  15. ^ Pittler MH, Verster JC, Ernst E. Interventions for preventing or treating alcohol hangover: systematic review of randomised controlled trials. BMJ. (2005)
  16. ^ a b Straumann A, et al. Acute pancreatitis due to pyritinol: an immune-mediated phenomenon. Gastroenterology. (1998)
  17. ^ Badalov N, et al. Drug-induced acute pancreatitis: an evidence-based review. Clin Gastroenterol Hepatol. (2007)
  18. ^ a b c d Maria V, et al. Severe cholestatic hepatitis induced by pyritinol. BMJ. (2004)
  19. ^ Macedo G, Sarmento JA, Allegro S. Acute hepatitis due to pyritinol. Gastroenterol Clin Biol. (1992)
  20. ^ Civatte J. Drug-induced pemphigus diseases. Dermatol Monatsschr. (1989)
  21. ^ Wigger-Alberti W, Elsner P. Occupational contact dermatitis due to pyritinol. Contact Dermatitis. (1997)
  22. ^ Nachbar F, Korting HC, Vogl T. Erythema multiforme-like eruption in association with severe headache following pyritinol. Dermatology. (1993)
  23. ^ Murata Y, et al. Photosensitive dermatitis caused by pyridoxine hydrochloride. J Am Acad Dermatol. (1998)
  24. ^ Tanaka M, et al. Photoallergic drug eruption due to pyridoxine hydrochloride. J Dermatol. (1996)
  25. ^ Faguer de Moustier B, et al. Auto-immune hypoglycemic syndrome induced by pyritinol. Diabete Metab. (1988)
  26. ^ Archambeaud-Mouveroux F, et al. Autoimmune hypoglycemia: the fault of pyritinol?. Presse Med. (1988)
  27. ^ Jaffe IA. Adverse effects profile of sulfhydryl compounds in man. Am J Med. (1986)