Herb Profile
Hibiscus
Hibiscus sabdariffa
Hibiscus (Hibiscus sabdariffa), also called roselle or sour tea, yields tart red calyces rich in anthocyanins and organic acids that are brewed as a tea.
Last reviewed: Report a correctionProfile-wide ·Unassigned
Standard caution — Generally safe; mild hypotension Details
- Evidence
- Editorial Grade Not Demonstrated By Recorded Studies
- Typical onset
- Varies by prep
- Safety rating
- Low caution
- Best for
- Stress Relief, Cardiovascular, Diuretic
- Avoid / review if
- Antihypertensives (Additive)
Safety
Safety & Cautions
Generally safe; mild hypotension
Standard caution
Caution level: Standard. No specific caution categories were detected in the source record.
Detailed safety fields
Pregnancy, breastfeeding, and contraindications
- Antihypertensives (Additive)
Full safety note
- Generally safe; mild hypotension
Evidence-based safety
Caution when combined
Severity and certainty are shown separately. A high-priority caution can still be theoretical: these pairings are screened from shared contraindication mechanisms and are not automatically documented clinical interactions. Provenance identifies the source fields that produced each flag; it does not upgrade the certainty of the pairwise claim.
Moderate Caution
81 flagged pairingsBlood-pressure effects
Moderate Caution
81 flagged pairingsBlood-pressure effects
Representative pairings are shown below. Large mechanism groups are intentionally summarized to keep profiles focused and crawl-efficient.
Blood-pressure effectsCertainty: Theoretical
Data provenance recorded for 81 of 81 pairings in this mechanism group.
- Agmatine sulfate — Theoretical interaction certainty
- ajoene — Theoretical interaction certainty
- Allicin — Theoretical interaction certainty
- American Ginseng Extract — Theoretical interaction certainty
- Andrographis — Theoretical interaction certainty
- Angelica Dahurica — Theoretical interaction certainty
- Astaxanthin — Theoretical interaction certainty
- Astragalus Membranaceus — Theoretical interaction certainty
- Beetroot extract — Theoretical interaction certainty
- Berberis — Theoretical interaction certainty
- Bicarbonate — Theoretical interaction certainty
- Black Seed — Theoretical interaction certainty
+69 more pairings share this mechanism. Use the Safety Checker to review a specific combination.
Evidence
Evidence Summary
Evidence lens
Treat this profile as unresolved until source review is complete.
Needs reviewEditorial Grade Not Demonstrated By Recorded Studies
Human clinical evidence: Not the primary signal
Mechanistic / preclinical: Mechanism mapped — Vascular Function Support · Stress Response Modulation
Research maturity: Theoretical / mechanistic research — Mechanistic or unresolved evidence is kept separate from established human outcomes.
Safety boundary: Safety note available — Generally safe; mild hypotension
How evidence grades work
Each grade reflects the strength and consistency of published human evidence — not marketing claims. Grades are based on study count, design quality, effect size, consistency, and recency.
- Strong
- Multiple RCTs, consistent direction, adequate effect size
- Moderate
- Some RCTs or consistent observational data in humans
- Preliminary / Mixed
- Animal or in-vitro only, or conflicting human data
- Traditional / Theoretical
- Traditional use only; no controlled human trials
Dosing & Timing
- Dose guidance
- 1.25 3 g tea/day or extract equivalent
How Hibiscus works
Simplified mechanism pathway based on preclinical and pharmacological evidence. Does not confirm clinical efficacy.
Mechanism Pathway — How Hibiscus Works
CompoundTarget / ReceptorMechanismEffect / Outcome
Mechanisms & biological pathways (preclinical)
- Vascular Function Support
- Stress Response Modulation
Compare related active botanicals
Explore botanicals with similar chemistry, effects, or safety considerations in the Botanical Activity Atlas.
Compare & Sourcing
Compare side-by-side tradeoffs or verify active marker guidelines.
Safety first · Harm reduction
This information is educational and not medical advice. Start low, avoid risky combinations, and consult a licensed clinician before making health decisions—especially if you use medications, have diagnosed conditions, or are pregnant/breastfeeding.
Learn how we evaluate confidence, safety, and intensity on the methodology page.
Founder & Head Researcher · Oak Ridge, TN · Last reviewed August 2026
Editorial Review
Checked against primary sources, cited evidence, and contraindication language before publication. Evidence claims, safety language, and affiliate modules are reviewed independently. Not personal medical advice.
Help improve this profile
Was this useful for your research?
These controls record only the page and the structured choice you make when analytics consent is enabled. Please don’t include personal medical information in research requests.
Was this evidence summary clear?
Did you find what you were researching?
Free safety checklist
Get the Hibiscus research notes
Evidence summaries, dosing context, and safety updates for this herb — straight to your inbox.
We use your email to send the checklist and occasional evidence-first supplement updates. Unsubscribe anytime. Privacy policy.