MedicinePOMEssential

Thiamine

Vitamin B1 tablets used to treat and prevent thiamine deficiency.

Clinical information

Common uses

treating vitamin B1 deficiency
preventing vitamin B1 deficiency
rare childhood conditions like maple syrup urine disease (specialist use)

Common side effects

feeling sick
diarrhoea
stomach ache

Cautions

avoid alcohol — it stops your body absorbing thiamine
tell your doctor before blood tests — it can affect results
rarely causes a serious allergic reaction

Interactions

fluorouracil (cancer medicine) — dose may need adjusting

Pregnancy: can be taken in pregnancy if recommended by a doctor

Reference information, not medical advice — always follow your doctor or pharmacist. Source: NHS Medicines A–Z, nhs.uk/medicines/thiamine-vitamin-b1 (accessed 2026-08-16)

Approved brands & formulations5

Brand name	Dosage form	Strength	Importer	Category
Thiamine	Tablet	500mg	—	POM
Thiamine	Tablet	250mg	—	POM
Thiamine	Tablet	100mg	—	POM
Thiamine	Parenteral ( Injection )	200mg/2 ml	MFDA designated importers with Pre Authorization approval before import	hospital
Thiamine	Tablet	50mg	—	POM