Thiamine Interactions

5 documented interactions5 warnings, 0 beneficial pairs.

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Interaction warnings

Thiamine + semaglutide

critical

Thiamine (vitamin B1) is the nutrient the brain exhausts fastest — reserves last only weeks. Semaglutide commonly reduces appetite and can cause prolonged nausea or vomiting, and where intake collapses for long enough, thiamine can run out. Running out causes Wernicke encephalopathy: confusion, unsteady walking and abnormal eye movements. It is reversible if treated within hours and can be permanent if missed. Eighteen cases have been published, fifteen of them following GLP-1 use, and in most the vomiting or poor intake came first.

Thiamine + tirzepatide

critical

Thiamine (vitamin B1) is the nutrient the brain exhausts fastest — reserves last only weeks. Tirzepatide commonly reduces appetite and can cause prolonged nausea or vomiting, and where intake collapses for long enough, thiamine can run out. Running out causes Wernicke encephalopathy: confusion, unsteady walking and abnormal eye movements. It is reversible if treated within hours and can be permanent if missed. Eighteen cases have been published, fifteen of them following GLP-1 use, and in most the vomiting or poor intake came first.

Thiamine + liraglutide

critical

Thiamine (vitamin B1) is the nutrient the brain exhausts fastest — reserves last only weeks. Liraglutide commonly reduces appetite and can cause prolonged nausea or vomiting, and where intake collapses for long enough, thiamine can run out. Running out causes Wernicke encephalopathy: confusion, unsteady walking and abnormal eye movements. It is reversible if treated within hours and can be permanent if missed. Eighteen cases have been published, fifteen of them following GLP-1 use, and in most the vomiting or poor intake came first.

Thiamine + alcohol

critical

Alcohol depletes thiamine (vitamin B1) at multiple levels — reducing its absorption from the gut, impairing the liver's ability to convert it to its active form, and increasing how much is lost in urine. In heavy drinkers this can lead to Wernicke encephalopathy, a neurologic emergency, which if untreated may progress to Korsakoff syndrome, a chronic and often irreversible memory disorder.

Thiamine + black tea

low

Black tea contains antithiamine factors - polyphenols such as tannins and chlorogenic acid - that can oxidise thiamine (vitamin B1) into biologically inactive forms in the gut before it is absorbed. Heavy habitual tea consumption has been linked to lower thiamine status, mainly in people whose dietary B1 intake is already marginal. For most well-nourished adults the effect is modest.

Related ingredients

Ingredients commonly checked alongside Thiamine.