Is Vitamin B12 (Methylcobalamin) Safe with Paroxetine?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Patients on long-term paroxetine, particularly older adults or those on concurrent proton pump inhibitors, should have annual B12 screening. Supplement with methylcobalamin 1000 mcg/day sublingually or orally if levels are borderline or deficient. Report new neurological symptoms such as tingling, memory changes, or worsening mood.
Why this interaction occurs
Paroxetine's anticholinergic activity reduces gastric acid secretion, impairing B12 release from dietary protein-bound sources and reducing intrinsic factor availability over time. Combined with age-related absorption decline and potential concurrent PPI use, long-term paroxetine use may create a clinically meaningful risk for B12 depletion. B12 deficiency can produce neuropsychiatric symptoms that may be misattributed to depression relapse or medication failure.
Evidence
Evidence level: moderate.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 53,308 reports mentioning Paroxetine. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Paroxetine + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Vitamin B12 (Methylcobalamin) interactions → · All Paroxetine interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.