Supplements and Felodipine.
Felodipine, sold under the brand names Plendil, Cardioplen XL, Felogen XL, Felotens XL, Vascalpha, Delofine, is a calcium channel blocker: it relaxes vascular smooth muscle and reduces afterload.
Felodipine 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 4 documented pairs we have explicitly assessed against Felodipine in the Distil database: 4 caution. The pairs cluster around 3 mechanisms: Reduced blood-pressure-medicine effect, CYP3A4 induction, 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 9 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.
Reduced blood-pressure-medicine effect
Caution Does Melatonin interact with Felodipine?
Melatonin has been shown to raise blood pressure and heart rate in people taking the related blood-pressure drug nifedipine, working against it. Felodipine is in the same drug family, so the same effect may apply. If you take felodipine, it is worth discussing melatonin with your prescriber and monitoring your blood pressure rather than starting it on your own.
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.
CYP3A4 induction
Caution Does St John's Wort interact with Felodipine?
St John's Wort may lower the amount of felodipine in your blood by speeding up its breakdown, so your blood pressure may be less well controlled. If you take felodipine, talk to your prescriber before starting St John's Wort, as your dose may need checking.
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.
CYP3A4 inhibition
Caution Does Berberine interact with Felodipine?
Berberine may raise felodipine blood levels by slowing the liver and gut enzyme that clears it, and it may also lower blood pressure a little on its own, so the combination can push blood pressure lower than intended. If you take both, check your blood pressure when you start berberine and tell your GP, especially if you notice dizziness, flushing, headache, a racing pulse or ankle swelling.
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.
Caution Does Bergamot Extract (BPF / Bergavit40) interact with Felodipine?
Bergamot is a citrus fruit related to grapefruit and contains bergamottin, one of the compounds behind grapefruit's effect on medicines, so it may raise felodipine blood levels. Felodipine is among the calcium-channel blockers most affected by grapefruit, so speak to your GP before combining, and watch for dizziness, flushing, headache or ankle swelling.
Evidence: Limited human data, from small studies or case reports.
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.
£49 until 30 June 2027 · £79 from 1 July 2027.
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