Relugolix and Mirabegron: 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
Mirabegron
Relugolix
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.
These two medicines can interact. Mirabegron (Myrbetriq) can slow down a 'pump' in your body called P-gp that normally helps move relugolix (Orgovyx) out. When that pump is blocked, more relugolix can build up in your blood. In one study with a similar blocker, relugolix levels roughly tripled.
Higher levels can mean a greater chance of side effects from relugolix, like hot flashes, tiredness, or other reactions. The good news is your care team knows how to handle this. They may adjust timing, watch you more closely, or choose another option. Please don't change anything on your own, just talk with your pharmacist or doctor.
Mechanism: Mirabegron inhibits P-gp, reducing efflux of relugolix (a P-gp substrate), increasing relugolix systemic exposure. Neither drug is a prodrug, so the effect is straightforward: increased relugolix effect and adverse-reaction risk.
- Magnitude: With erythromycin (P-gp inhibitor), relugolix AUC increased 3.5-fold and Cmax 2.9-fold; expect a similar-direction effect.
- Evidence/onset: Probable; onset unspecified.
- Management: Avoid coadministration if possible. If unavoidable, give relugolix first and separate by >=6 hours, and monitor adverse reactions more frequently. For short P-gp inhibitor courses, relugolix may be interrupted up to 2 weeks; if held >7 days, restart with 360 mg loading dose then 120 mg daily.
What happens
Increased relugolix exposure
Interaction Deep Dive
Do not use relugolix (which is a P-gp substrate) together with P-gp inhibitors, because doing so can raise relugolix exposure and thereby heighten the likelihood of adverse reactions linked to relugolix. 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 interrupted for more than 7 days, it should be restarted using a loading dose of 360 mg on day one, followed by 120 mg once daily thereafter. In a drug interaction study, giving relugolix (P-gp substrate) alongside erythromycin (P-gp inhibitor) raised relugolix AUC by 3.5-fold and Cmax by 2.9-fold1.
Why it happens (mechanism)
Inhibition of P-gp-mediated efflux transport of relugolix
How to manage this interaction
What your care team may do:
- Try to avoid using these together when possible.
- If both are needed, take relugolix first and separate the two doses by at least 6 hours.
- Monitor you more closely for relugolix side effects.
- Sometimes pause relugolix during a short course of the interacting drug, then resume it (with a loading dose if it was held more than 7 days).
What you should do: Keep taking both exactly as prescribed and don't stop or change anything on your own. Let your pharmacist or prescriber know you take both so they can tailor the plan and timing for you.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) During a drug interaction study, giving relugolix (a P-gp substrate) together with erythromycin (a P-gp inhibitor) raised the AUC of relugolix by 3.5-fold and its Cmax by 2.9-fold 1.
Common questions
Can I take Relugolix and Mirabegron together?
Mirabegron can raise relugolix levels by blocking a transporter, increasing side-effect risk, so your care team may avoid the combination, space the doses, or monitor you closely. Don't change anything yourself; check with your pharmacist or doctor. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Mirabegron 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 Relugolix and Mirabegron interaction managed?
What your care team may do: Try to avoid using these together when possible. If both are needed, take relugolix first and separate the two doses by at least 6 hours. Monitor you more closely for relugolix side effects. Sometimes pause relugolix during a short course of the interacting drug, then resume it (with a loading dose if it was held more than 7 days). What you should do: Keep taking both 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 Relugolix or Mirabegron 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 Mirabegron
Keep reading about Relugolix
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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