Iron and medications.
Iron is in the Distil supplement database, evidence Grade A. The page below lists every medication we have explicitly assessed it against.
Iron carries oxygen and underpins energy and clear thinking, and low ferritin tracks with worse ADHD symptoms and poor stamina. Ferrous bisglycinate is the best-tolerated form, ahead of gluconate and then sulfate, which is the one that tends to upset the gut. The single non-negotiable rule is the blood test: never supplement iron without a confirmed low ferritin, because iron overload does real harm and the body has no easy way to shed excess. A full blood count is not a substitute, because it is usually normal when iron stores are low but anaemia has not yet developed. Evidence is Grade A for correcting deficiency and Grade B for physical performance (Pasricha 2014). For ADHD it is Grade C: ferritin runs markedly lower in children with ADHD (Konofal 2004), but that is a case-control association rather than a trial, and the only supplementation study is a 23-person pilot in which both the parent and teacher rating scales fell short of significance. Timing drives most of the interactions. Separate iron from zinc, calcium and magnesium by two hours, from tea, coffee and dairy by one hour, and from antibiotics by two hours. Vitamin C taken alongside markedly improves absorption. Take it with food, and keep it well away from children.
Below are the 13 documented pairs we have explicitly assessed for Iron: 13 amber. The pairs cluster around 2 mechanisms: Absorption interference and Mineral chelation (absorption). Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication into our next curation pass.
Documented interactions
Last reviewed 14 June 2026. Each interaction below lists the evidence its assessment drew on: some rest on studies of the exact pair, others on mechanism evidence, where a citation may support one part of the reasoning rather than the exact combination. The evidence line on each entry says which.
Absorption interference
Amber Does interact with Esomeprazole?
Non-haem iron from supplements absorbs less well in a low-acid stomach, so chronic esomeprazole use reduces iron uptake from a standard ferrous sulphate or ferrous fumarate tablet. Iron bisglycinate is less pH-dependent and a better choice on a long-term PPI. Taking iron in the morning on an empty stomach with vitamin C also helps. Always confirm ferritin is in the deficient range before supplementing iron.
Evidence: Supported by human study data.
Amber Does interact with Famotidine?
Famotidine reduces stomach acid, and non-haem iron absorbs less well in a low-acid stomach, so it can lower iron uptake from a standard ferrous sulphate or ferrous fumarate tablet. The effect tends to be less marked than with a PPI like omeprazole, because famotidine suppresses acid less completely. Iron bisglycinate is less pH-dependent, and taking iron in the morning on an empty stomach with vitamin C helps. Always confirm ferritin is in the deficient range before supplementing iron.
Evidence: Supported by human study data.
Amber Does interact with Lansoprazole?
Non-haem iron from supplements absorbs less well in a low-acid stomach, so chronic lansoprazole use reduces iron uptake from a standard ferrous sulphate or ferrous fumarate tablet. Iron bisglycinate is less pH-dependent and a better choice on a long-term PPI. Taking iron in the morning on an empty stomach with vitamin C also helps. Always confirm ferritin is in the deficient range before supplementing iron.
Evidence: Supported by human study data.
Amber Does interact with Omeprazole?
Non-haem iron from supplements absorbs less well in a low-acid stomach, so chronic omeprazole use reduces iron uptake from a standard ferrous sulphate or ferrous fumarate tablet. Iron bisglycinate is less pH-dependent and a better choice on a long-term PPI. Always confirm ferritin is in the deficient range before supplementing iron.
Evidence: Supported by human study data.
Amber Does interact with Pantoprazole?
Non-haem iron from supplements absorbs less well in a low-acid stomach, so chronic pantoprazole use reduces iron uptake from a standard ferrous sulphate or ferrous fumarate tablet. Iron bisglycinate is less pH-dependent and a better choice on a long-term PPI. Taking iron in the morning on an empty stomach with vitamin C also helps. Always confirm ferritin is in the deficient range before supplementing iron.
Evidence: Supported by human study data.
Mineral chelation (absorption)
Amber Does interact with Alendronic acid?
Iron binds to alendronic acid in the gut and blocks absorption in the same way calcium does. Take alendronic acid first thing on an empty stomach with plain water, stay upright for 30 minutes, then wait at least two hours before any iron supplement.
Evidence: Supported by human study data.
Amber Does interact with Ciprofloxacin?
Iron binds to ciprofloxacin in the gut and can cut the amount of antibiotic you absorb by more than half, which may let an infection persist. Take ciprofloxacin at least two hours before, or six hours after, any iron supplement.
Evidence: Supported by human study data.
Amber Does interact with Co-beneldopa (Benserazide/levodopa)?
Iron binds levodopa in the gut and reduces how much you absorb, which can weaken your Parkinson's symptom control. Take your co-beneldopa dose and any iron supplement at least two hours apart. Only take iron if a blood test has confirmed your ferritin is low, as Distil does not recommend iron without confirmed deficiency.
Evidence: Supported by human study data.
Amber Does interact with Co-careldopa (Carbidopa/levodopa)?
Iron binds levodopa and carbidopa in the gut and reduces how much of each you absorb, which can weaken your Parkinson's symptom control. Take your co-careldopa dose and any iron supplement at least two hours apart. Only take iron if a blood test has confirmed your ferritin is low, as Distil does not recommend iron without confirmed deficiency.
Evidence: Supported by human study data.
Amber Does interact with Doxycycline?
Iron binds to doxycycline in the gut and can seriously reduce how much antibiotic you absorb, which may let an infection persist. Take doxycycline at least two hours before, or six hours after, any iron supplement.
Evidence: Supported by human study data.
Amber Does interact with Levothyroxine?
Iron can bind to levothyroxine in the gut and reduce how much you absorb. Separating doses by four hours usually solves it.
Evidence: Supported by human study data.
Amber Does interact with Minocycline?
Iron can bind to minocycline in the gut and lower how much antibiotic your body absorbs, which may make it less effective. Minocycline is absorbed better than older tetracyclines so the effect is smaller, but it is still worth keeping the two apart: take minocycline at least 2 hours before or 6 hours after your iron supplement.
Evidence: Limited human data, based on case reports and a known mechanism.
Amber Does interact with Risedronate sodium?
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.
Evidence: Supported by human study data.
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. Use the checker below to surface any medication, and submit a missing item if you take something we have not catalogued.
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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 methodologyA full supplement review, built around you, not a generic stack.
The free checker answers one interaction question at a time. A Distil report reviews the bigger picture: your goals, diet, medications, current supplements and any blood results you provide, then shows what appears worth keeping, changing, adding or leaving out.
- what your diet already covers, so you are not adding a capsule for something food is already handling
- which evidence-graded compounds are worth considering for your goals, and which were considered but left out
- what to keep, change or stop from what you already take, plus the order to introduce anything new
- how your medications and complete supplement stack fit together, with daily timing and a clear point for reassessment
The interaction check is one section of the full report. You also get the reasoning behind each recommendation and the evidence references used.
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