The short answer
A reliable quercetin dose or timing rule for cyclosporine has not been established. Animal studies show altered cyclosporine exposure, while the complete results of a published human report were unavailable for this review. Have concentrated quercetin supplements reviewed before use; uncertainty does not establish that the combination is safe.
What this answer covers
Oral quercetin supplements with systemic oral cyclosporine. This assessment does not assign the same effect to ordinary dietary amounts, rutin, quercetin glycosides or enhanced-bioavailability formulations. Animal cyclosporine preparations are identified separately.
- Supplement or preparation
- Quercetin
- Medication ingredient
- cyclosporine
What did the accessible experiments show?
Experiments in pigs and rats found lower cyclosporine exposure when quercetin was given with it. A later rat study also found lower peaks after repeated quercetin dosing. The animals received substantial doses, and one experiment gave diluted cyclosporine injection concentrate by mouth. These conditions do not establish what happens with a patient’s usual capsules.
Has this combination been studied in people?
A human report on oral cyclosporine and quercetin was published in 2004. Its bibliographic record could be verified, but no abstract or complete original text was accessible. Consequently, numerical human results quoted elsewhere cannot be independently confirmed here. It would be misleading either to repeat those percentages as verified or to say no human study exists.
Can a laboratory mechanism decide the answer?
Quercetin can affect enzymes and transport systems involved in drug handling, but those effects do not reliably predict the net change in the body. In one animal study, a separate intestinal experiment showed transporter inhibition even though overall cyclosporine exposure fell. A mechanism alone cannot determine a personal dose adjustment or prove that separating doses will help.
What is the practical next step?
Ask the prescribing team to review the exact supplement, dose and reason for taking it. Cyclosporine requires blood-level and kidney monitoring, so a new concentrated product or a major change deserves discussion. No verified quercetin requirement or protective interval is established here. Do not change cyclosporine or restrict ordinary foods based only on the animal results.
Evidence and practical considerations
Timing & monitoring
A reliable quercetin dose or timing rule for cyclosporine has not been established. Animal studies show altered cyclosporine exposure, while the complete results of a published human report were unavailable for this review. Have concentrated quercetin supplements reviewed before use; uncertainty does not establish that the combination is safe.
- Exact scope
- Oral quercetin supplements with systemic oral cyclosporine. This assessment does not assign the same effect to ordinary dietary amounts, rutin, quercetin glycosides or enhanced-bioavailability formulations. Animal cyclosporine preparations are identified separately. with Cyclosporine, RxCUI 3008, IN, systemic oral use. Neoral modified microemulsion and conventional Sandimmune are distinguished; neither is automatically dose-equivalent to the other. The Neoral label identifies cyclosporine as the active ingredient and basis of strength. Intravenous reference experiments are identified separately; ophthalmic and topical use are excluded.
- Medication form and route
- oral
- Timing or duration
- Only the durations described in the sources are established; no untested persistence or dose-spacing interval is inferred.
What remains uncertain
- Human publication access gap; animal models, high doses and nonstandard oral preparation. No established supplement requirement, exact human direction, dose correction or spacing interval.
Factors that may matter: concentrated versus dietary exposure; quercetin formulation; cyclosporine formulation; unavailable original human results.
Read the supporting source summaries
Source 1: regulatory prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients prescribed systemic oral cyclosporine, including transplant recipients.
Requires clinical and blood-level monitoring, recognizes nephrotoxicity and hyperkalemia, cautions with potassium-containing drugs and explicitly advises avoiding grapefruit and grapefruit juice. Neoral and Sandimmune are not bioequivalent.
How this applies: Direct exact-medication identity and oral monitoring guidance. Pair-specific applicability is restricted to the named food or potassium-containing products; other supplements require their own evidence.
A regulatory label does not quantify each supplement interaction. Botanical effects and absolute event rates cannot be inferred from cyclosporine toxicity alone. Formulation-specific findings must be retained.
Source 2: primary animal pharmacokinetic experiment
pmc.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Twenty-four male rats in the pharmacokinetic experiment, eight per quercetin dose group; separate tissue experiments.
Peak cyclosporine fell about 46-50%. Exposure fell numerically across groups, with the high-dose AUC decrease about 33-34% statistically significant. The paper discusses a separate human study but does not provide its original data.
How this applies: Exact chemicals but nonhuman and unusual oral preparation. Supports uncertainty and a possible interaction, not a proven human separation rule.
Animal dosing, Cremophor-containing oral gavage preparation, and no human timing comparison. Animal decreases cannot establish the direction or a dose correction in patients. The referenced human results were not independently accessible.
Source 3: primary animal pharmacokinetic experiment
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Pigs and rats, plus an isolated intestinal-sac experiment; no human participants.
Cyclosporin AUC over 0-3 hours decreased 56% in pigs; AUC to the final sample decreased 43% in rats. The separate intestinal experiment showed transporter inhibition, illustrating that mechanism alone did not predict the net effect.
How this applies: Potential interaction signal for concentrated quercetin, with no transfer to routine dietary exposure or related glycosides such as rutin.
Abstract only; animal findings and differing AUC windows cannot establish a human effect size. No clinical supplement requirement, food restriction, or spacing interval was studied.
Source 4: primary-study bibliographic record without accessible results
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Not verified from accessible original methods; indexed as a human study.
The publication and bibliographic identity were verified. No original quantitative clinical result was available for assessment.
How this applies: Establishes that human research exists; it does not support or refute the clinical interaction claim, quantify it or supply management instructions.
Bibliographic record only, no abstract and no accessible original full text. Numerical summaries in later papers or AI pages are excluded as independently verified human evidence.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Original studies and regulatory sources checked; a new article prepared with exact formulation and access limits. No independent clinical review is recorded. | |
| Research summary published |
Article revision: 36415cef22fb2f6f
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.