Your Side Effects May IncludeMetformin (Glucophage) side effects
This side effect is printed on the FDA label for Metformin. It was a question in our daily quiz, where you pick the real side effect from four choices.
Low vitamin B12
In one trial, about 7% of people saw their B12 levels drop below normal.
“a decrease to subnormal levels of previously normal serum vitamin B12 levels was observed in approximately 7% of patients”
Ask about checking your B12. Get help right away for unusual muscle pain, trouble breathing or extreme sleepiness, signs of a rare but serious problem called lactic acidosis.
716 reports to the FDA's adverse event system mention vitamin B12 deficiency. A report is not proof the drug caused it. See the query
From quiz No. 6 · September 30, 2026 · Play that quiz →
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