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Supplement · Considered, not recommended

Red Yeast Rice and medications.

Why it sits outside our recommendations, and what to consider instead.

Red Yeast Rice is not in the Distil recommendation database. We surface it here deliberately, because why a compound is left out is as useful as what we recommend.

Red yeast rice is a statin sold as a supplement. It naturally contains monacolin K, which is the exact same molecule as the prescription statin lovastatin, and that single fact is why it sits outside the Distil database. Taken on top of a prescribed statin it is two statins at once, which raises the risk of muscle injury, including the serious form called rhabdomyolysis, with no added benefit. On its own it carries the same muscle and liver risks as any statin.

The bigger problem is that the monacolin content is unregulated and varies widely between products, so the statin dose you are actually taking is unknown. A medicine this consequential belongs under prescription with monitoring, not bought blind off a shelf. The documented pairs below are the statin-on-statin combinations to avoid. For lipids, the options below have a cleaner profile, though none replaces a statin where one is genuinely needed.

What to consider instead. Every option below is in the Distil database, so you can check each against your own medications:

We still hold the documented interactions for Red Yeast Rice, which is why it stays in the interactions checker even though we do not recommend it. Below are the 4 documented pairs we have explicitly assessed: 4 red. Every call is cited to a clinical reference (PMID) or the British National Formulary.

Documented interactions

Additive muscle toxicity

Red yeast rice is a statin. It naturally contains monacolin K, which is the same molecule as the prescription statin lovastatin. Taking it on top of atorvastatin means you are taking two statins at once, which may raise the risk of muscle damage, including a serious form called rhabdomyolysis. Do not combine the two without your GP's guidance.

Red yeast rice is a statin. It naturally contains monacolin K, the same molecule as the prescription statin lovastatin. Taking it alongside simvastatin means two statins at once. Simvastatin is one of the more muscle-prone statins, so the combination may raise the risk of muscle damage, including the serious form called rhabdomyolysis. Do not combine the two without your GP's guidance.

CYP3A4 inhibition

Red yeast rice is a statin in disguise. It naturally contains monacolin K, the same molecule as the prescription statin lovastatin, and that statin is cleared by a liver enzyme called CYP3A4. Clarithromycin strongly blocks that enzyme, so taking the two together can push the statin in red yeast rice to much higher levels than intended and raise the risk of muscle damage, including the serious form called rhabdomyolysis. Do not combine them. If you need clarithromycin, stop the red yeast rice for the course and speak to your GP or pharmacist.

PMID 31628882 · PMID 12438974 · PMID 28093797 · BNF: Clarithromycin

Red yeast rice is a statin in disguise. It naturally contains monacolin K, the same molecule as the prescription statin lovastatin, and that statin is cleared by a liver enzyme called CYP3A4. Erythromycin blocks that enzyme, so taking the two together can push the statin in red yeast rice to much higher levels than intended and raise the risk of muscle damage, including the serious form called rhabdomyolysis. Do not combine them. If you need erythromycin, stop the red yeast rice for the course and speak to your GP or pharmacist.

PMID 31628882 · PMID 12438974 · PMID 28093797 · BNF: Erythromycin

What this page does not say. Leaving a compound out of our recommendations is not a verdict that it is useless for everyone. It is a statement about safety, evidence, or interaction load in the context Distil screens for. Discuss any supplement decision with whoever manages your prescriptions.

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For adults over 18. This tool gives evidence-graded information, not medical advice. Always discuss changes with your GP, especially if you take any medication, are pregnant, breastfeeding, or have a serious health condition.
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How we decide

How we grade severity, choose what's in scope, and what we exclude.

Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.

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Your whole stack

Want this reasoning across everything you take?

This page checks the pairs you enter. A personalised Distil report applies the same graded, cited reasoning to your whole stack: your goals, conditions, medications, diet, and the compounds worth adding or dropping. The interactions check is one section of it. You can read a real one in full before you decide.

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Distil's interactions database is reviewed and updated every quarter. We grade evidence transparently and publish our methodology, including every database change, at /about/methodology. This tool is information, not a substitute for clinical judgement. If you take medication and supplements together, your GP or pharmacist can review your full regimen against your medical history. If you want a full personalised stack reasoned against this same database, the Distil report is the next step up.