Supplements and Verapamil hydrochloride.
Verapamil hydrochloride, sold under the brand names Securon, Cordilox, Univer, Calan, Verelan, Isoptin, is a calcium channel blocker: it relaxes vascular smooth muscle and reduces afterload.
Verapamil hydrochloride is a calcium channel blocker. The dihydropyridines (amlodipine, felodipine, nifedipine) mainly block arterial L-type channels and are prescribed for hypertension. Verapamil and diltiazem also slow conduction through the heart and are used for arrhythmia control. CYP3A4 clears the whole class, so CYP3A4 inhibitors may raise levels, least for amlodipine, which loses little to first-pass metabolism. Grapefruit juice is the known example; schisandra and berberine may act the same way, and so may bergamot, whose bergamottin, a CYP3A4 inhibitor, raised felodipine levels in volunteers, though no bergamot product has been tested. With verapamil and diltiazem a raised level can slow the pulse as well as lower blood pressure. Ankle oedema, common with the dihydropyridines, scales with dose. Beetroot, hibiscus, garlic and taurine may add to the blood-pressure fall. CoQ10 lowers systolic pressure by about 5 mmHg in cardiometabolic conditions (Zhao 2022), though a Cochrane review of two small trials found no significant effect in primary hypertension and no study has tested it alongside a blood-pressure drug, so watch readings rather than treat it as a known interaction.
Below are the 5 documented pairs we have explicitly assessed against Verapamil hydrochloride in the Distil database: 5 caution. The pairs cluster around 2 mechanisms: Additive blood-pressure lowering and CYP3A4 inhibition. 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 13 October 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.
Additive blood-pressure lowering
Caution Does Beetroot Extract interact with Verapamil hydrochloride?
Beetroot lowers blood pressure through the nitric oxide pathway. Verapamil lowers blood pressure through calcium-channel blockade and also slows the heart rate. Used together, the combined blood-pressure effect tends to be larger than either alone. Watch for dizziness on standing in the first two weeks. If symptoms appear, tell your GP.
Evidence: Limited human data, from small studies or case reports.
Caution Does Garlic Extract interact with Verapamil hydrochloride?
Garlic supplements may lower blood pressure a little, mostly when it is above target, and verapamil lowers it too, so together they may bring it down a bit further. Verapamil also slows the heart, and garlic has not been shown to add to that in people. If you feel dizzy or light-headed, especially when you stand up, check your blood pressure and tell your GP; garlic's effect tends to build over several weeks.
Evidence: Limited human data, from small studies or case reports.
Caution Does Spirulina interact with Verapamil hydrochloride?
Spirulina has a mild blood-pressure-lowering effect of its own, shown in human trials. Verapamil lowers blood pressure through calcium-channel blockade and also slows the heart rate. Used together, the combined effect tends to be a little larger than the medicine alone. Watch for dizziness on standing in the first couple of weeks, and tell your GP if it happens so your dose can be reviewed.
Evidence: Limited human data, from small studies or case reports.
Caution Does Taurine interact with Verapamil hydrochloride?
Taurine may lower blood pressure a little on its own, and verapamil lowers blood pressure and slows the heart, so taken together the blood-pressure effects may add up. Watch for dizziness on standing, unusual tiredness or a pulse that feels slower than usual, especially in the first couple of weeks of taking both, and tell your GP if that happens. Taurine's own effect on blood pressure is small.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
CYP3A4 inhibition
Caution Does Berberine interact with Verapamil hydrochloride?
Berberine may raise verapamil blood levels by slowing the enzyme that clears it, so your pulse and blood pressure may fall further than intended, and berberine may also lower blood pressure a little on its own. If you take both, check your pulse and blood pressure when you start berberine and tell your GP, especially if you feel dizzy, faint, unusually tired or short of breath.
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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