Herb Profile
Grapefruit
Grapefruit carries a Grade C rating — limited evidence.
Last reviewed: Report a correctionProfile-wide ·C Limited
Use extra caution — Major food drug interaction risk: can raise exposure of statins, calcium channel blockers, immunosuppressants, antiarrhythmics, and other CYP3A4/OATP substrates. Details
- Evidence
- Limited Evidence
- Typical onset
- Varies by prep
- Safety rating
- High caution
- Best for
- Digestive, Metabolic health
- Avoid / review if
- Avoid Or Medically Supervise With Drugs Labeled For Grapefruit Interaction, Narrow Therapeutic Index Drugs, And Complex Cardiovascular/Transplant Regimens.
Safety
Safety & Cautions
Major food drug interaction risk: can raise exposure of statins, calcium channel blockers, immunosuppressants, antiarrhythmics, and other CYP3A4/OATP substrates.
High caution
Caution level: High. Multiple caution categories apply, or the record uses avoid/contraindication language.
- Interaction-AwareMedication or interaction context is explicitly noted.
Detailed safety fields
Pregnancy, breastfeeding, and contraindications
- Avoid Or Medically Supervise With Drugs Labeled For Grapefruit Interaction
- Narrow Therapeutic Index Drugs
- And Complex Cardiovascular/Transplant Regimens.
- CYP3A4
- P Gp
- And OATP Mediated Interactions
- Effects May Persist Beyond A Single Serving.
Safety classifications
- Interaction-Aware: Medication or interaction context is explicitly noted.
Full safety note
- Major food drug interaction risk: can raise exposure of statins, calcium channel blockers, immunosuppressants, antiarrhythmics, and other CYP3A4/OATP substrates.
Safety labels
- Interaction-Aware
Evidence
Evidence Summary
Evidence lens
Read as directional context, not settled clinical proof.
LimitedLimited Evidence
Human clinical evidence: Not the primary signal
Mechanistic / preclinical: Mechanism mapped — Metabolic Regulation
Research maturity: Theoretical / mechanistic research — Mechanistic or unresolved evidence is kept separate from established human outcomes.
Safety boundary: Safety note available — Major food drug interaction risk: can raise exposure of statins, calcium channel blockers, immunosuppressants, antiarrhythmics, and other CYP3A4/OATP substrates.
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
- No standardized dose
- Preparation specific; use standardized product label for Interaction risk varies by whole fruit and require source backed dosage review before therapeutic claims.
How Grapefruit works
Simplified mechanism pathway based on preclinical and pharmacological evidence. Does not confirm clinical efficacy.
Mechanism Pathway — How Grapefruit Works
CompoundTarget / ReceptorMechanismEffect / Outcome
Mechanisms & biological pathways (preclinical)
- Metabolic Regulation
Active Compounds
Key constituents studied in Grapefruit, with full pharmacology and safety profiles.
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.
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