Hibiscus Extract and medications.
Hibiscus Extract is in the Distil supplement database, evidence Grade B. The page below lists every medication we have explicitly assessed it against.
Hibiscus extract comes from the dried calyces of Hibiscus sabdariffa, the same plant behind sour or roselle tea. It has Grade B evidence for lowering blood pressure, both systolic and diastolic, and offers some antioxidant and mild lipid effects. A 2015 meta-analysis of five RCTs found systolic reductions of around 7.6 mmHg, and trials in prehypertensive and diabetic hypertensive adults showed meaningful drops, so it may support people working on blood pressure alongside diet. The honest limit is that effect sizes vary with dose and baseline, and the strongest results come from people who already had raised pressure. On interactions, the effect that matters is additive: taken with antihypertensive medicines it can lower pressure further, so monitoring is sensible, and there is some pharmacokinetic interaction with hydrochlorothiazide. Hepatotoxicity is only a concern at very high doses. If you take blood pressure medication, it is worth flagging to your GP and keeping an eye on readings rather than assuming the two simply add up safely.
Below are the 11 documented pairs we have explicitly assessed for Hibiscus Extract: 11 caution. The pairs cluster around 2 mechanisms: Absorption interference and Additive blood-pressure lowering. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication into our next curation pass.
Documented interactions
Last reviewed 15 June 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 blood-pressure lowering
Caution Does Hibiscus Extract interact with Amlodipine?
Hibiscus tends to lower blood pressure on its own, and amlodipine lowers it by relaxing blood vessels. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. If symptoms appear, tell your GP.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Hibiscus Extract interact with Bendroflumethiazide?
Hibiscus tends to lower blood pressure on its own, and bendroflumethiazide is a water tablet used to lower it. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. If symptoms appear, tell your GP.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Hibiscus Extract interact with Bisoprolol?
Hibiscus tends to lower blood pressure on its own, and bisoprolol is a beta blocker that lowers it too. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. If symptoms appear, tell your GP.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Hibiscus Extract interact with Candesartan cilexetil?
Hibiscus tends to lower blood pressure on its own, and candesartan lowers it by blocking the angiotensin receptor. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. If symptoms appear, tell your GP.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Hibiscus Extract interact with Clonidine?
Hibiscus tends to lower blood pressure on its own, and clonidine lowers it too. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. If symptoms appear, tell your GP.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Hibiscus Extract interact with Guanfacine?
Hibiscus tends to lower blood pressure on its own, and guanfacine lowers it too. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. If symptoms appear, tell your GP.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Hibiscus Extract interact with Indapamide?
Hibiscus tends to lower blood pressure on its own, and indapamide is a water tablet used to lower it. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. If symptoms appear, tell your GP.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Hibiscus Extract interact with Lisinopril?
Hibiscus tends to lower blood pressure on its own, and lisinopril lowers it by blocking the angiotensin-converting enzyme. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. If symptoms appear, tell your GP.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Hibiscus Extract interact with Losartan?
Hibiscus tends to lower blood pressure on its own, and losartan lowers it by blocking the angiotensin receptor. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. If symptoms appear, tell your GP.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Hibiscus Extract interact with Ramipril?
Hibiscus tends to lower blood pressure on its own, and ramipril lowers it by blocking the angiotensin-converting enzyme. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. If symptoms appear, tell your GP.
Evidence: Limited human data, from small studies or case reports.
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. Use the checker below to surface any medication, 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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