Medication · other drugs for genitourinary disorders

Supplements and Sildenafil (Erectile Dysfunction).

Every documented pair, every citation. Below: 2 documented pairs grouped by mechanism.

Sildenafil (Erectile Dysfunction), sold under the brand names Viagra, Granpidam, Revatio, is classified under "drugs for genitourinary disorders" in the BNF.

Sildenafil (Erectile Dysfunction) (UK brand names Viagra, Granpidam, Revatio) sits at NHSBSA prescribing rank 72 in the 2024/25 PCA statistics. The BNF classifies it under "drugs for genitourinary disorders". 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 Sildenafil (Erectile Dysfunction) with a regular supplement stack benefits from explicit GP or pharmacist awareness rather than assuming no interaction exists by default.

Below are the 2 documented pairs we have explicitly assessed against Sildenafil (Erectile Dysfunction) in the Distil database: 2 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

Amber Beetroot Extract

Sildenafil and beetroot both increase nitric-oxide-driven vasodilation, by different routes. Prescription organic nitrate medications (GTN spray, isosorbide) are strictly contraindicated with sildenafil because of severe blood pressure drops. Beetroot acts through the same downstream nitric oxide pathway but produces much lower nitric oxide levels than prescription nitrates. The theoretical risk is additive vasodilation and symptomatic low blood pressure. Tell your GP if you take both.

PMID 25421976 · BNF: Sildenafil

Reviewer-flagged: awaiting clinical-reviewer sign-off.

Amber L-Citrulline

L-citrulline raises nitric oxide, which widens blood vessels, and sildenafil works on the same nitric oxide pathway. Combining them could add up to a larger drop in blood pressure, so watch for dizziness, flushing, or faintness, particularly in the few hours after a sildenafil dose. Tell your GP if you take both.

PMID 30029482 · PMID 31336573 · PMID 21195829 · BNF: Sildenafil

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.

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For adults over 18. This tool gives evidence-graded information, not medical advice. Always discuss changes with your GP, especially if you take any medication, are pregnant, breastfeeding, or have a serious health condition.

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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.

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Distil's interactions database is reviewed and updated every quarter. We grade evidence transparently and publish our methodology, including every database change, at /about/methodology. This tool is information, not a substitute for clinical judgement. If you take medication and supplements together, your GP or pharmacist can review your full regimen against your medical history. If you want a full personalised stack reasoned against this same database, the Distil report is the next step up.