Last Updated: September 28 2022

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.

Pyritinol is most often used for

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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.


Pyritinol, 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]


Effects 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]


Safety 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.^Greiner HE, Haase AF, Seyfried CANeurochemical studies on the mechanism of action of pyritinolPharmacopsychiatry.(1988 Aug)
4.^Martin KJ, Tucker L, Widdowson LEffects of some metabolites of pyritinol (Encephabol) on ACH release from brain slicesPharmacopsychiatry.(1988 Aug)
6.^Fischhof PK, Saletu B, Rüther E, Litschauer G, Möslinger-Gehmayr R, Herrmann WMTherapeutic efficacy of pyritinol in patients with senile dementia of the Alzheimer type (SDAT) and multi-infarct dementia (MID)Neuropsychobiology.(1992)
7.^Cooper AJ, Magnus RVA placebo-controlled study of pyritinol ('Encephabol') in dementiaPharmatherapeutica.(1980)
9.^Slánská JControlled study of the effect of pyritinol in geronto-patientsAct Nerv Super (Praha).(1990 Mar)
12.^Elferink JG, de Koster BMDifferential stimulation of neutrophil functions by pyrithioxineInt J Immunopharmacol.(1993 Jul)
16.^Straumann A, Bauer M, Pichler WJ, Pirovino MAcute pancreatitis due to pyritinol: an immune-mediated phenomenonGastroenterology.(1998 Aug)
17.^Badalov N, Baradarian R, Iswara K, Li J, Steinberg W, Tenner SDrug-induced acute pancreatitis: an evidence-based reviewClin Gastroenterol Hepatol.(2007 Jun)
18.^Maria V, Albuquerque A, Loureiro A, Sousa A, Victorino RSevere cholestatic hepatitis induced by pyritinolBMJ.(2004 Mar 6)
19.^Macedo G, Sarmento JA, Allegro SAcute hepatitis due to pyritinolGastroenterol Clin Biol.(1992)
20.^Civatte JDrug-induced pemphigus diseasesDermatol Monatsschr.(1989)
21.^Wigger-Alberti W, Elsner POccupational contact dermatitis due to pyritinolContact Dermatitis.(1997 Aug)
23.^Murata Y, Kumano K, Ueda T, Araki N, Nakamura T, Tani MPhotosensitive dermatitis caused by pyridoxine hydrochlorideJ Am Acad Dermatol.(1998 Aug)
24.^Tanaka M, Niizeki H, Shimizu S, Miyakawa SPhotoallergic drug eruption due to pyridoxine hydrochlorideJ Dermatol.(1996 Oct)
25.^Faguer de Moustier B, Burgard M, Boitard C, Desplanque N, Fanjoux J, Tchobroutsky GAuto-immune hypoglycemic syndrome induced by pyritinolDiabete Metab.(1988 Jul-Aug)
26.^Archambeaud-Mouveroux F, Canivet B, Fressinaud C, de Buhan B, Treves R, Laubie BAutoimmune hypoglycemia: the fault of pyritinol?Presse Med.(1988 Oct 8)