Supplements and Isosorbide mononitrate.
Isosorbide mononitrate, sold under the brand names Imdur, Monosorb XL, Modisal XL, Chemydur 60XL, Zemon XL, is classified under "nitrate" in the BNF.
Isosorbide mononitrate (UK brand names Imdur, Monosorb XL, Modisal XL, Chemydur 60XL, Zemon XL) sits at NHSBSA prescribing rank 53 in the 2024/25 PCA statistics. The BNF classifies it under "nitrate". This means it sits outside the high-volume therapeutic classes (statins, PPIs, ACE inhibitors, SSRIs) where supplement-interaction surfaces are densely studied, and the published evidence base for specific supplement pairs is correspondingly thinner. Where interactions are documented in the Distil database, they are listed below with their clinical-reference citation; where pairs have not been explicitly assessed, the missing-item form at the bottom of the page routes them into our next curation pass. Anyone combining Isosorbide mononitrate with a regular supplement stack benefits from explicit GP or pharmacist awareness rather than assuming no interaction exists by default.
Below are the 3 documented pairs we have explicitly assessed against Isosorbide mononitrate in the Distil database: 3 amber. The pairs cluster around 1 mechanism: Additive vasodilation. 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
Additive vasodilation
Isosorbide mononitrate is an organic nitrate that widens blood vessels by releasing nitric oxide. Beetroot acts on the same nitric oxide pathway by a different route. Taken together the blood-pressure-lowering effects can add up, so you may notice more dizziness, lightheadedness or a headache. This is additive rather than the dangerous amplified drop seen when nitrates are combined with erection medicines such as sildenafil. Keep your beetroot intake steady and tell your GP or cardiologist you take it.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Isosorbide mononitrate is an organic nitrate that widens blood vessels by releasing nitric oxide. L-citrulline raises nitric oxide by a different route, by feeding the arginine pathway. Taken together the blood-pressure-lowering effects can add up, so you may notice more dizziness, lightheadedness or a headache. This is additive rather than the dangerous amplified drop seen when nitrates are combined with erection medicines such as sildenafil. Keep your citrulline dose steady and tell your GP or cardiologist you take it.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
NAC is a sulfur-rich compound, and nitrate medicines like isosorbide mononitrate rely on sulfur groups in the body to work. Taking the two together may make the nitrate act more strongly, which can mean a more pronounced headache and a larger drop in blood pressure than the nitrate alone. If you take isosorbide mononitrate and want to use NAC, watch for dizziness, faintness on standing, or worse headaches, and tell your GP or pharmacist so they can review the timing or doses.
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 (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.
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.
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- the same graded, cited interaction check across your whole stack, not just the pairs you thought to type in
- where your current routine may be leaving you short of your goals
- the evidence-backed compounds worth adding, and the ones worth dropping
It's a paid report: £79, or £49 for the first 25 customers. The interactions check is one section of it, and you can read a real one in full before you buy.
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