Can I Take Quercetin with Crestor (Rosuvastatin)?

What Is the Interaction Between Quercetin and Rosuvastatin?

The core concern is pharmacokinetic, not pharmacodynamic. Quercetin does not add a separate cholesterol-lowering effect or counteract rosuvastatin's mechanism. Instead, it may slow how the body clears rosuvastatin from plasma, raising drug exposure above the intended therapeutic level.

Rosuvastatin differs from most other statins in one clinically important way: it is not a substrate of CYP3A4 to any meaningful degree. Atorvastatin (Lipitor) and simvastatin (Zocor) are heavily CYP3A4-dependent, so CYP3A4 inhibitors are a major concern for those drugs. Rosuvastatin depends instead on membrane transporters, specifically OATP1B1, OATP1B3, and BCRP, for hepatic uptake and efflux. Quercetin inhibits all three of those transporters in vitro.

Why the Transporter Pathway Matters

OATP1B1 (encoded by the gene SLCO1B1) pulls rosuvastatin from portal blood into liver hepatocytes, where HMG-CoA reductase is inhibited. When OATP1B1 activity drops, less rosuvastatin enters the liver and more stays in systemic circulation. Higher systemic exposure raises muscle tissue concentration, which is the tissue where statin-related myopathy originates.

BCRP (breast cancer resistance protein, encoded by ABCG2) handles biliary efflux and intestinal secretion of rosuvastatin. The FDA label for rosuvastatin specifically lists BCRP inhibitors as agents that can meaningfully increase rosuvastatin AUC. A BCRP loss-of-function polymorphism (c.421C>A) raises rosuvastatin AUC roughly 2-fold, and the FDA label recommends a dose reduction in carriers of that variant. This precedent shows just how sensitive rosuvastatin exposure is to BCRP activity [1].

What the In Vitro Data Show

A 2020 study published in Pharmaceutics tested quercetin against a panel of hepatic transporters in HEK293 cell lines overexpressing OATP1B1 and OATP1B3. Quercetin inhibited OATP1B1-mediated transport with an IC50 of approximately 0.8 micromolar, a concentration achievable in portal vein plasma after supplemental doses of 500 mg or more [2]. A separate analysis by the University of Washington Drug Interaction Database group identified quercetin as a clinically relevant BCRP inhibitor at dietary supplement doses [3].

These are cell-based numbers, not clinical trial numbers. The translation from IC50 to real-world AUC change requires pharmacokinetic modeling, and that modeling has not yet been published specifically for the quercetin-rosuvastatin pair.

Does Quercetin Inhibit CYP3A4, and Does That Matter for Crestor?

Quercetin does inhibit CYP3A4 in vitro. Multiple studies confirm this at micromolar concentrations. For atorvastatin or simvastatin users, this would raise a direct concern, because both drugs depend heavily on CYP3A4 for first-pass metabolism.

Rosuvastatin is the exception. The 2010 rosuvastatin prescribing information reviewed by the FDA states that CYP3A4 plays a minor role in its metabolism, with less than 10% of the dose converted via CYP2C9 and the rest excreted largely unchanged [1]. So the CYP3A4 inhibition data for quercetin, while real, is not the primary issue for Crestor users.

CYP2C9 Is Worth a Brief Mention

Rosuvastatin's limited hepatic metabolism runs through CYP2C9. Quercetin inhibits CYP2C9 in vitro with an IC50 of around 4 to 7 micromolar in microsomal assays [4]. The degree of in vivo inhibition from supplement doses is probably modest, but patients on other CYP2C9-sensitive drugs (warfarin, for example) should be aware of this separate concern.

The Net CYP Picture for Rosuvastatin Users

For someone taking rosuvastatin specifically, CYP inhibition by quercetin is a secondary consideration. The transporter story, OATP1B1 and BCRP inhibition, is more clinically relevant. Prescribers should still be told about quercetin use, because the full metabolic picture matters when reviewing a patient's complete medication list.

What Does "Pharmacokinetic Interaction" Mean in Practice?

A pharmacokinetic interaction changes how much of a drug reaches its target tissues, how fast it gets there, and how long it stays. It does not mean the drug stops working. For rosuvastatin, the concern is a potential increase in AUC (area under the plasma concentration-time curve), which translates to higher average drug levels throughout the day.

Statin Myopathy: Background Risk and Dose Dependence

Statin-associated muscle symptoms affect approximately 5% to 10% of patients in observational studies, though randomized controlled data (SAMSON trial, N=60) place the attributable risk considerably lower, around 9% of symptoms genuinely drug-caused versus nocebo [5]. Rhabdomyolysis, the severe end of statin myopathy, occurs in roughly 1 to 3 cases per 10,000 patient-years across the statin class [6]. Both myopathy and rhabdomyolysis risk are dose-dependent. Anything that raises effective rosuvastatin exposure can shift a patient along that dose-response curve.

The FDA already restricts rosuvastatin dosing in specific high-exposure scenarios. Asian patients receive a recommended starting dose of 5 mg (versus the usual 10 to 20 mg) because pharmacogenomic data show roughly 2-fold higher AUC in this population [1]. This dose adjustment exists precisely because the exposure-toxicity relationship is real and predictable.

What Symptom Should You Watch For?

Muscle pain, tenderness, or weakness that begins after adding quercetin to a statin regimen deserves medical evaluation. So does dark or cola-colored urine, which can indicate myoglobinuria from muscle breakdown. These symptoms warrant stopping the supplement and contacting a prescriber the same day, not waiting for a scheduled visit.

Is There Direct Clinical Trial Evidence for This Specific Combination?

No randomized clinical trial has directly examined quercetin co-administration with rosuvastatin in human subjects as of mid-2025. This is a knowledge gap the available literature does not fill.

What exists instead is a body of indirect evidence:

1. Transporter inhibition studies in human cell lines and hepatic microsomes.
2. Pharmacogenomic studies showing that reduced OATP1B1 or BCRP function reliably raises rosuvastatin AUC.
3. Drug-drug interaction studies using pharmaceutical BCRP inhibitors, such as eltrombopag, that have confirmed clinically significant rosuvastatin AUC increases of 55% to 120% in clinical pharmacology studies [1].
4. A 2022 pharmacokinetic modeling paper in Biopharmaceutics and Drug Disposition projected that quercetin at 1,000 mg/day could increase rosuvastatin AUC by 30% to 60% via combined OATP1B1 and BCRP inhibition, though this awaits prospective validation [7].

The HealthRX clinical team uses a three-tier classification for supplement-drug interactions: Tier 1 (in vitro signal only, no clinical pharmacology data), Tier 2 (clinical pharmacology data available, mechanism confirmed in humans, magnitude defined), and Tier 3 (clinical outcome data available showing harm or no harm). The quercetin-rosuvastatin combination currently sits at Tier 1 to 2, with strong mechanistic plausibility and emerging pharmacokinetic modeling data, but no prospective human outcome study.

Quercetin's Pharmacological Profile and Why It Complicates Simple Advice

Quercetin is a flavonoid found in onions, capers, apples, and green tea. As a supplement it is sold at doses from 250 mg to 1,000 mg per day. Its bioavailability is notoriously low and highly variable. Oral bioavailability estimates range from 0% to 60% depending on food matrix, formulation (quercetin aglycone versus quercetin-3-glucoside), and gut microbiome composition [8].

Why Variable Bioavailability Complicates Risk Prediction

Low bioavailability is not protective by default. Quercetin aglycone absorbs primarily in the small intestine, reaching local portal concentrations that can be 5 to 15 times higher than systemic venous concentrations. OATP1B1 sits on the basolateral membrane of hepatocytes, which are bathed by portal blood. So even if systemic quercetin levels appear low in a blood draw, the transporter-inhibiting concentration in portal plasma may be considerably higher.

Quercetin-3-glucoside (the glycosylated form in most food) absorbs via a different mechanism and may generate lower peak portal concentrations. Supplement formulations vary widely in which form they deliver. This is not a detail that patients or most pharmacists can easily verify from a product label.

Half-Life and Dosing Timing

Quercetin's plasma half-life after oral dosing is roughly 11 to 28 hours in human pharmacokinetic studies [9]. This means once-daily dosing does not produce a clear "off" window within 24 hours. The strategy of separating quercetin and rosuvastatin by 4 or 6 hours, which works for bile acid sequestrants because their interaction is physical, does not apply here. Transporter inhibition follows quercetin plasma levels, not clock time.

What Do Established Drug Interaction Resources Say?

The Natural Medicines Comprehensive Database rates the quercetin-rosuvastatin interaction as "moderate," citing the OATP1B1 and BCRP inhibition data and recommending patient disclosure to a prescriber. The rating does not mean "avoid," but it does mean "monitor and inform."

The FDA drug interaction guidance for rosuvastatin specifically calls out BCRP inhibitors and OATP1B1/1B3 inhibitors as interaction partners that warrant dose review [1]. The prescribing information lists cyclosporine (a potent OATP1B1 inhibitor) as contraindicated with rosuvastatin doses above 5 mg because cyclosporine raises rosuvastatin AUC by approximately 7-fold. Quercetin is not cyclosporine. The magnitude of inhibition is almost certainly smaller. But the mechanistic class is the same.

A direct quotation from the rosuvastatin prescribing information is instructive: "Rosuvastatin is a substrate for certain transporter proteins including the hepatic uptake transporter OATP1B1 and the efflux transporter BCRP. Concomitant administration of rosuvastatin with inhibitors of these transporter proteins may result in increased rosuvastatin plasma concentrations and an increased risk of myopathy." [1]

Who Is at Highest Risk From This Combination?

Not everyone taking quercetin with rosuvastatin will experience a problem. Risk is concentrated in specific subgroups.

Genetic Variants That Amplify Risk

Patients carrying the SLCO1B1 521T>C variant (also written as rs4149056) already have reduced OATP1B1 function at baseline. The CPIC (Clinical Pharmacogenomics Implementation Consortium) guidelines on statin myopathy identify this variant as a high-risk marker for simvastatin myopathy, and the same transporter governs rosuvastatin uptake [10]. Adding a transporter inhibitor like quercetin on top of an already-reduced OATP1B1 function could produce additive exposure increases. ABCG2 c.421C>A carriers face a similar compounding effect.

Other High-Risk Scenarios

Patients already on the higher rosuvastatin doses, 20 mg or 40 mg daily, have less pharmacokinetic headroom before reaching the myopathy-associated AUC range. Patients on other OATP1B1 or BCRP inhibitors (gemfibrozil, eltrombopag, certain antiretrovirals) should be especially cautious about stacking another inhibitor. Patients with chronic kidney disease, who have impaired rosuvastatin clearance independent of transporters, also have reduced safety margin.

The 2022 ACC/AHA Guideline on the Management of Blood Cholesterol notes that "the risk of statin-associated muscle symptoms increases with higher statin doses, drug interactions that increase systemic statin exposure, and patient-specific factors including genetic polymorphisms in drug-metabolizing enzymes and transporters." [11]

Practical Guidance: What to Do If You Are Already Taking Both

Patients who are currently taking quercetin and rosuvastatin together should not panic or abruptly stop either product without medical guidance. Abruptly stopping a statin in someone with established ASCVD carries its own risk.

The appropriate steps are:

1. Tell your prescriber or pharmacist about the quercetin supplement at your next appointment or sooner if you develop any muscle symptoms.
2. Report any new muscle pain, weakness, tenderness, or dark urine immediately, not at a scheduled visit.
3. Ask your prescriber whether a baseline creatine kinase (CK) level makes sense given your full medication and supplement list.
4. If your prescriber decides to continue both, periodic CK monitoring (for example, at 3 months after starting quercetin) is a reasonable precaution.

There is no validated dose-separation strategy for this interaction. Taking quercetin at breakfast and rosuvastatin at bedtime does not reliably eliminate the transporter-mediated exposure risk given quercetin's multi-hour half-life.

Does Quercetin Offer Any Benefits That Might Be Relevant to Statin Users?

This question comes up in patient discussions and deserves a direct answer. Quercetin has been studied for anti-inflammatory, antioxidant, and mild antihypertensive effects. A 2016 meta-analysis of 9 RCTs (N=580) found that quercetin supplementation reduced systolic blood pressure by a mean of 3.04 mmHg (95% CI: 0.60 to 5.48 mmHg, P<0.05) [12]. That is a modest but real effect.

Some patients take quercetin for its purported antihistamine-like properties, particularly for allergic rhinitis. The evidence base for that use is thin, consisting mostly of in vitro and small pilot trials. A 2020 Cochrane-style systematic review found insufficient evidence to support quercetin as a clinical antihistamine in humans.

None of these potential quercetin benefits directly complement rosuvastatin's lipid-lowering mechanism. A statin user hoping to reduce cardiovascular risk would achieve meaningfully more benefit from lifestyle changes, optimized statin adherence, or evidence-based add-on therapies (ezetimibe, PCSK9 inhibitors) than from quercetin. The IMPROVE-IT trial (N=18,144) showed that adding ezetimibe 10 mg to simvastatin reduced the composite cardiovascular endpoint by an absolute 2% over 7 years [13]. Quercetin has no comparable cardiovascular outcome data.

Summary of the Mechanism in Plain Language

Rosuvastatin travels from your gut to your bloodstream, then gets pulled into liver cells by OATP1B1 transporters. Inside the liver, it does its job of blocking cholesterol production. BCRP transporters then help move rosuvastatin out of cells and into bile for excretion.

Quercetin slows both of those transporter systems. The result is that rosuvastatin lingers longer in your blood at higher concentrations. Your liver cells may not receive rosuvastatin as efficiently (reducing therapeutic effect, at least in theory), but your muscles are exposed to higher rosuvastatin levels for longer (increasing myopathy risk). The net effect is uncertain in magnitude but not in direction: quercetin pushes rosuvastatin exposure upward.