Supplements and Diclofenac sodium.
Diclofenac sodium, sold under the brand names Voltarol, Voltaren, Voltarol Pain-eze, is a non-steroidal anti-inflammatory drug (NSAID): it inhibits cyclooxygenase enzymes, with documented gastrointestinal and renal long-term risks.
Diclofenac sodium is an NSAID, a non-steroidal anti-inflammatory drug. The class inhibits cyclooxygenase enzymes (COX-1 and COX-2 depending on selectivity), reducing pain and inflammation driven by prostaglandins. It also reduces the protective gastric and renal prostaglandin signalling that drives the side effect profile. Use at high doses or sustained over time carries gastric ulceration risk (mitigated when a PPI is given alongside), reduced antihypertensive effect of ACE inhibitors and ARBs, additive renal stress in CKD3+, and additive antiplatelet effect with aspirin or clopidogrel. The supplement surface divides into two patterns. Compounds that target the same pathway (curcumin, boswellia, omega-3 EPA at higher doses) overlap mechanism with NSAIDs in the COX cascade. Additive effects are real but rarely problematic at OTC doses. Ginkgo, garlic extract, and fish oil at high doses add to bleeding risk when stacked with NSAIDs, especially around dental work or surgery.
Below are the 6 documented pairs we have explicitly assessed against Diclofenac sodium in the Distil database: 6 caution. The pairs cluster around 4 mechanisms: Absorption interference, Additive hyperkalaemia (raised potassium), Additive antiplatelet effect, and Reduced renal lithium clearance. 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
Last reviewed 12 November 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
Caution Does Hibiscus Extract interact with Diclofenac sodium?
A small human study found that drinking a hibiscus beverage alongside diclofenac changed how much of the drug appeared in the urine, which suggests hibiscus may slightly affect how diclofenac is handled by the body. The effect is not well characterised and may be minor, but if you take both regularly it is worth separating them by a couple of hours and mentioning it to your GP or pharmacist.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Additive hyperkalaemia (raised potassium)
Caution Does Potassium interact with Diclofenac sodium?
Anti-inflammatory painkillers like diclofenac can make the kidneys hold on to a little more potassium. On their own the effect is usually small, but added to a potassium supplement, and especially if your kidneys are not working at full strength or you take a blood-pressure medicine that also raises potassium, it can nudge your potassium higher. If you take diclofenac regularly, mention any potassium supplement to your GP or pharmacist.
Evidence: Supported by human study data.
Additive antiplatelet effect
Caution Does Garlic Extract interact with Diclofenac sodium?
High-dose garlic extract has its own mild antiplatelet effect on top of diclofenac's. For occasional pain relief at standard doses, this is rarely a problem. For chronic NSAID use or pre-surgery, the combined effect can mean more bleeding and bruising.
Evidence: Limited human data, from small studies or case reports.
Caution Does Ginkgo Biloba interact with Diclofenac sodium?
Diclofenac can make bleeding more likely, especially from the stomach, and ginkgo has been linked to reports of bleeding. In trials in people, ginkgo at the 120 to 240mg doses sold in the UK has not shown a meaningful effect on standard clotting tests, so the caution rests on those reports rather than on a proven blood-thinning effect. Used together for short periods at standard doses, any added risk is likely to be small; used at high doses for long periods, the two together may mean more bleeding and bruising. Stop ginkgo at least two weeks before any planned surgery.
Evidence: Limited human data, from small studies or case reports.
Caution Does Omega-3 EPA interact with Diclofenac sodium?
High-dose omega-3 has a mild antiplatelet effect that adds to diclofenac's. At typical supplement doses and short-course NSAID use, the combined effect is usually mild. At high doses or for chronic NSAID use, the additive bleeding tendency is worth knowing about.
Evidence: Limited human data, from small studies or case reports.
Reduced renal lithium clearance
Caution Does Lithium Orotate interact with Diclofenac sodium?
Anti-inflammatory painkillers such as diclofenac can make the kidneys hold on to lithium, which raises the lithium level in the blood. With prescription lithium this is a recognised caution. At the small amount of lithium in a typical lithium orotate supplement (around 5 mg) the effect is expected to be very small; it matters more for higher-strength products (around 20 mg) and for anyone whose kidney function is reduced. If you take regular anti-inflammatories, check with your pharmacist or GP before using a lithium supplement.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
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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How the checker decides
Every result has a source
Each pair we have assessed is cited to a published study (PMID) or the British National Formulary, so you can read the source yourself.
Four kinds of answer
Severe, caution, no known interaction, and not yet assessed. A pair we have not assessed is never shown as clear.
- Severe
- Caution
- No known interaction
- Not yet assessed
Nothing in our data is not a clearance
When nothing in our data records a problem with a pair, the result says no known interaction at typical doses, which is not a clearance: your pharmacist or GP can check the pair against your full medical history.
A 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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