The short answer
Avoid starting red yeast rice with oral ketoconazole without the prescriber’s review. Some products contain monacolin K, the same compound as lovastatin, which is contraindicated with oral ketoconazole because of muscle-toxicity risk.
What this answer covers
Monacolin-containing red yeast rice with oral ketoconazole. Monacolin K identity with lovastatin is explicit; content varies and not all products contain detectable amounts.
- Supplement or preparation
- Red yeast rice
- Medication ingredient
- ketoconazole
Check the exact medicine and regimen
This review applies to oral ketoconazole tablets, whose use is limited because of serious systemic risks. It does not assign the same interactions to ketoconazole shampoo or skin cream. Keep the prescribed indication, other medicines and liver-monitoring plan in view.
The active constituent matters
Red yeast rice can contain monacolin K, chemically identical to lovastatin. The ketoconazole label contraindicates lovastatin because inhibiting its metabolism can increase exposure and muscle toxicity. This is a defined-constituent bridge, not a measured trial of every red yeast rice product.
Product weight does not establish the dose
An analytical study found large differences in monacolin K among 28 brands, including two without detectable amounts. A label showing only milligrams of fermented rice cannot reliably identify the active dose. Those findings do not demonstrate that an untested product is safe.
A time gap is not a substitute
Discuss the cholesterol-treatment plan and exact product with the prescriber. A few hours of separation has not been shown to prevent this metabolic interaction. New muscle pain or marked weakness warrants prompt assessment; continue the prescribed monitoring for oral ketoconazole’s separate liver risks.
Evidence and practical considerations
Side effects & toxicity
A constituent-based muscle-toxicity precaution is supported for monacolin-containing products; a universal combined liver/muscle toxicity rate is not established.
- Exact scope
- Monacolin-containing red yeast rice with oral ketoconazole. Monacolin K identity with lovastatin is explicit; content varies and not all products contain detectable amounts. with RxNorm 6135 IN ketoconazole. Exact oral 200 mg base tablets; topical creams, shampoos and other local routes are not comparable systemic exposure.
- Medication form and route
- Oral
What remains uncertain
- Analytical constituent identity plus lovastatin contraindication, not an exact red-yeast-rice combination trial. Original bundled liver/muscle/elevated-level claim exceeds measured exact-pair evidence; no universal product event rate.
Factors that may matter: Exact oral regimen and formulation; Booster or fixed-combination context; Mineral preparation and dosing order; Food requirements.
Read the supporting source summaries
Source 1: Current original prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients prescribed the specified oral regimen.
Reduced acidity impairs absorption; acid-neutralizing drugs at least one hour before or two hours after. Serious liver toxicity warning and contraindication with lovastatin/simvastatin.
How this applies: RxNorm 6135 IN ketoconazole. Exact oral 200 mg base tablets; topical creams, shampoos and other local routes are not comparable systemic exposure.
No automatic topical route transfer, fruit-extract interaction or every-mineral binding effect. Constituent bridges and liver-risk precaution distinct from exact-pair clinical event data.
Source 2: Original clinical research
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: 28 commercial red yeast rice brands.
Monacolin K, chemically identical to lovastatin, varied markedly; absent in two brands.
How this applies: Exact reported regimen, preparation and endpoints only; other drugs or forms remain indirect.
Analytical study, not a ketoconazole co-use trial. Product mass does not establish monacolin dose.
Source 3: Medication terminology
rxnav.nlm.nih.gov · Source check Sep 10, 2026
Population: Terminology.
ketoconazole is IN.
How this applies: Exact ingredient.
Not clinical evidence.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Research summary published | |
| Article prepared | |
| Sources checked and article drafted. |
Article revision: 64f0b7971a7044e7
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.