Supplement interactions: questions for your pharmacist
Updated 3 November 2026 · Root & Evidence editorial content · No independent clinical review claimed
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Bring a complete list
Include prescription and over-the-counter medicines, herbs, vitamins, powders, doses, and frequency. Include occasional products, not just daily ones.
Separate kinds of risk
Some products affect medicine absorption; others add to a medicine’s effects or change its metabolism. An online list cannot rule out every interaction.
When to ask first
Ask before adding supplements if pregnant or breastfeeding, preparing for surgery, treating a chronic condition, or taking medicines. Kidney or liver disease can change risk.
Use the ingredient-specific notes
Our guides flag selected concerns: magnesium and absorption, ashwagandha and thyroid/sedative medicines, berberine and cyclosporine, and omega-3s with anticoagulants. They are starting points, not a complete safety clearance.