Supplements and Risedronate sodium.
Risedronate sodium, sold under the brand names Actonel, Actonel Once a Week, is a bisphosphonate. Oral absorption is reduced by polyvalent cations including calcium, magnesium and iron.
Below are the 3 documented pairs we have explicitly assessed against Risedronate sodium in the Distil database: 3 amber. The pairs cluster around 1 mechanism: Mineral chelation (absorption). Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not on this list is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by supplement, and the missing-item form at the bottom of the page routes any uncatalogued supplement into our next curation pass.
Documented interactions
Mineral chelation (absorption)
Calcium binds to risedronate in the gut and almost completely blocks how much you absorb. Take risedronate first thing on an empty stomach with plain water, stay upright for 30 minutes, then wait at least two hours before any calcium-containing food, drink or supplement.
Iron binds to risedronate in the gut and blocks absorption. Take risedronate first thing on an empty stomach with plain water, stay upright for 30 minutes, then wait at least two hours before any iron supplement.
Magnesium binds to risedronate in the gut and blocks absorption. Take risedronate first thing on an empty stomach with plain water, stay upright for 30 minutes, then wait at least two hours before any magnesium supplement.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope (food-supplement interactions only; for drug-drug interactions, the BNF is authoritative). Use the checker below to surface any supplement, and submit a missing item if you take something we have not catalogued.
For adults over 18.
This tool gives evidence-graded information, not medical advice. Always discuss changes with your GP, pharmacist, or specialist before making them, especially if you take any medication, are pregnant, breastfeeding, or have a serious health condition.
How we grade severity, choose what's in scope, and what we exclude.
Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.
Read the full methodologySomething missing?
If a supplement or medication you take isn't in our autocomplete, tell us and we'll add it in the next quarterly update.