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 in women of reproductive age (Pasricha 2014, a synthesis of trials run in women). 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. Calcium can reduce how much iron you absorb, zinc can do the same when the two are taken together on an empty stomach, and the evidence for magnesium is thin and comes mostly from antacids, so keeping all three about two hours away from your iron is a simple precaution. The NHS advises leaving two hours after taking iron before having tea, coffee, eggs or dairy. Some antibiotics need a different gap, because iron can cut how much of the antibiotic you absorb, which may let an infection persist. Take ciprofloxacin or doxycycline at least two hours before, or six hours after, any iron supplement. Vitamin C does increase how much iron you absorb from a tablet, but trials comparing iron with and without it found little or no difference in haemoglobin or ferritin, so there is no need to buy it specially or time it with your iron. Iron is absorbed best on an empty stomach, but taking it with or after food is fine if it upsets your stomach. Keep it well away from children.
Below are the 24 documented pairs we have explicitly assessed for Iron: 23 amber and 1 green. 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 31 August 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 Iron 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 Iron 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 Iron 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 Iron 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 Iron 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 Iron 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 Iron interact with Bictegravir?
Iron can bind to Bictegravir in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. Bictegravir is usually taken at least 2 hours BEFORE a magnesium or aluminium antacid, and taking it 2 hours after is not equivalent. Taking it with food at the same time is the other option. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Supported by human study data.
Amber Does Iron interact with Bictegravir with emtricitabine and tenofovir alafenamide?
Iron can bind to Biktarvy in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. Bictegravir is usually taken at least 2 hours BEFORE a magnesium or aluminium antacid, and taking it 2 hours after is not equivalent. Taking it with food at the same time is the other option. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Supported by human study data.
Amber Does Iron 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 Iron 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 Iron 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 Iron interact with Dolutegravir?
Iron can bind to Dolutegravir (Tivicay) in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. When fasted, the HIV medicine is usually taken at least 2 hours before, or 6 hours after, the supplement. Taking them at the same time with food is also an option and works for calcium, iron and magnesium. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Supported by human study data.
Amber Does Iron interact with Dolutegravir with abacavir and lamivudine?
Iron can bind to Triumeq in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. When fasted, the HIV medicine is usually taken at least 2 hours before, or 6 hours after, the supplement. Taking them at the same time with food is also an option and works for calcium, iron and magnesium. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Supported by human study data.
Amber Does Iron interact with Dolutegravir with lamivudine?
Iron can bind to Dovato in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. When fasted, the HIV medicine is usually taken at least 2 hours before, or 6 hours after, the supplement. Taking them at the same time with food is also an option and works for calcium, iron and magnesium. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Supported by human study data.
Amber Does Iron interact with Dolutegravir with rilpivirine?
Iron can bind to Juluca in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. When fasted, the HIV medicine is usually taken at least 2 hours before, or 6 hours after, the supplement. Taking them at the same time with food is also an option and works for calcium, iron and magnesium. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Supported by human study data.
Amber Does Iron 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 Iron interact with Elvitegravir?
Iron can bind to Elvitegravir in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. The UK label asks for at least 4 hours between the two, in either direction. Taking them together with food is NOT offered as an alternative here, unlike dolutegravir and bictegravir. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Limited human data, from small studies or case reports.
Amber Does Iron interact with Elvitegravir with cobicistat, emtricitabine and tenofovir alafenamide?
Iron can bind to Genvoya in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. The UK label asks for at least 4 hours between the two, in either direction. Taking them together with food is NOT offered as an alternative here, unlike dolutegravir and bictegravir. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Limited human data, from small studies or case reports.
Amber Does Iron interact with Elvitegravir with cobicistat, emtricitabine and tenofovir disoproxil?
Iron can bind to Stribild in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. The UK label asks for at least 4 hours between the two, in either direction. Taking them together with food is NOT offered as an alternative here, unlike dolutegravir and bictegravir. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Limited human data, from small studies or case reports.
Amber Does Iron 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 Iron 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, from small studies or case reports.
Amber Does Iron interact with Raltegravir?
Iron can bind to Raltegravir (Isentress) in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. Spacing the doses apart may not be enough on its own for raltegravir, so this is one to settle with the HIV team rather than to manage with a gap. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Limited human data, from small studies or case reports.
Amber Does Iron 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.
Other
Green Does Iron interact with Doravirine?
Iron and doravirine can be taken together. Doravirine was studied alongside an aluminium and magnesium antacid and the amount absorbed stayed the same. Unlike the integrase inhibitor HIV medicines, doravirine works without binding metal ions, so there is no reason to space them apart.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
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.
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