Quercetin and Relugolix: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Relugolix
Quercetin
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Here's what's going on. Relugolix (Orgovyx) is moved out of your body with the help of a little cellular "pump" called P-gp. Quercetin, a supplement found in many plant-based products, can slow that pump down. When the pump is slowed, more relugolix stays in your body than intended.
That extra relugolix can mean more side effects, such as hot flashes, fatigue, or increased blood pressure. The good news is that this is very manageable. Don't stop either one on your own. Just let your pharmacist or doctor know you're taking quercetin so they can guide the timing, watch you a bit more closely, or suggest an alternative.
Effect: Increased relugolix exposure. Relugolix is a P-gp substrate; quercetin is a reported P-gp inhibitor, so inhibition of intestinal P-gp-mediated efflux is expected to raise relugolix AUC and Cmax, increasing the risk of adverse reactions. Neither is a prodrug, so the direction is straightforward potentiation.
- Magnitude: Not quantified for quercetin. For reference, erythromycin (P-gp inhibitor) raised relugolix AUC 3.5-fold and Cmax 2.9-fold.
- Evidence: Probable. Severity: major. Onset: unspecified.
- Management: Avoid coadministration. If unavoidable, give relugolix first, separate by at least 6 hours, and monitor adverse reactions more frequently.
What happens
Increased relugolix exposure
Interaction Deep Dive
Do not use relugolix (a P-gp substrate) together with P-gp inhibitors, because doing so can raise relugolix exposure and thereby heighten the likelihood of relugolix-related adverse reactions. When coadministration cannot be avoided, give relugolix or relugolix/estradiol/norethindrone acetate first, allow a gap of at least 6 hours between doses, and increase the frequency of monitoring for adverse reactions12. Relugolix therapy may be paused for as long as 2 weeks to accommodate a brief course of certain P-gp inhibitors, with relugolix resumed once the P-gp inhibitor has been stopped. Should relugolix be withheld for more than 7 days, restart it using a 360 mg loading dose on the first day and then continue at 120 mg once daily. In a drug interaction study, giving relugolix (P-gp substrate) alongside erythromycin (P-gp inhibitor) raised the AUC and Cmax of relugolix by 3.5-fold and 2.9-fold, respectively1.
Why it happens (mechanism)
Inhibition of P-gp-mediated efflux transport of relugolix
How to manage this interaction
Keep taking relugolix as prescribed and tell your care team about the quercetin supplement. Because supplements are not always necessary, your team may prefer you avoid it while on relugolix.
- Your team may advise avoiding the combination when possible.
- If both are needed, they may have you take relugolix first and separate the doses by at least 6 hours.
- They may monitor you more closely for side effects such as hot flashes, fatigue, or blood pressure changes.
- Don't start, stop, or change your relugolix dose on your own. Any dose changes will be individualized by your prescriber.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In a drug interaction study, giving relugolix (a P-gp substrate) together with erythromycin (a P-gp inhibitor) raised the AUC and Cmax of relugolix by 3.5-fold and 2.9-fold, respectively 1.
Common questions
Can I take Quercetin and Relugolix together?
Quercetin can raise relugolix levels and increase side effects, so it's best avoided; tell your pharmacist or doctor about the supplement and don't change your relugolix on your own. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Quercetin and Relugolix interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Quercetin and Relugolix interaction managed?
Keep taking relugolix as prescribed and tell your care team about the quercetin supplement. Because supplements are not always necessary, your team may prefer you avoid it while on relugolix. Your team may advise avoiding the combination when possible. If both are needed, they may have you take relugolix first and separate the doses by at least 6 hours. They may monitor you more closely for side e… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Quercetin or Relugolix need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: ORGOVYX oral tablets, relugolix oral tablets. Sumitomo Pharma America, Inc (per FDA), Marlborough, MA, 2025. DailyMed
- Product Information: MYFEMBREE(R) oral tablets, relugolix, estradiol, norethindrone acetate oral tablets. Myovant Sciences Inc (per FDA), Brisbane, CA, 2021. DailyMed
Keep reading about Relugolix
Keep reading about Quercetin
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