Danicopan 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
Danicopan
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. Danicopan can block a 'pump' in your body (called P-gp) that normally helps move relugolix out. When that pump is slowed down, more relugolix can build up in your blood. In one study with a similar pump-blocker, relugolix levels rose by roughly three times.
More relugolix in your system can mean a higher chance of side effects like hot flashes, mood changes, tiredness, or joint pain. The good news is that your care team can manage this by adjusting timing, watching you more closely, or choosing another plan. Please don't stop or change either medicine on your own. Just talk with your pharmacist or doctor first.
Mechanism: Danicopan inhibits P-gp-mediated efflux of relugolix (a P-gp substrate), increasing relugolix systemic exposure. Neither drug relies on prodrug activation here, so the effect is a straightforward increase in relugolix concentrations.
- Direction/magnitude: Increased relugolix AUC/Cmax. A study with erythromycin (P-gp inhibitor) showed 3.5-fold AUC and 2.9-fold Cmax increases.
- Evidence/onset: Probable; onset unspecified.
- Management: Avoid concomitant use. If unavoidable, give relugolix first and separate by at least 6 hours; monitor more frequently for adverse reactions. Relugolix may be interrupted up to 2 weeks for short P-gp inhibitor courses; if interrupted >7 days, restart with a 360 mg loading dose then 120 mg daily.
What happens
Increased relugolix exposure
Interaction Deep Dive
Concurrent administration of relugolix (a P-gp substrate) with P-gp inhibitors should be avoided, since 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 minimum of 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 short 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, reinitiate it using a 360 mg loading dose on day one, followed by 120 mg once daily thereafter. In a drug interaction study, giving relugolix (P-gp substrate) together with erythromycin (P-gp inhibitor) raised relugolix AUC and Cmax 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
What your care team may do:
- Try to avoid using these two together when possible, or choose an alternative.
- 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.
- In some cases, relugolix may be paused for a short course of danicopan, then restarted (with the standard loading dose if the pause was longer than 7 days).
What you should do: Keep taking both exactly as prescribed unless told otherwise, and let your pharmacist or prescriber know you are on both so they can tailor your dosing and monitoring.
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 relugolix AUC by 3.5-fold and Cmax by 2.9-fold, respectively 1.
Common questions
Can I take Danicopan and Relugolix together?
Danicopan can raise relugolix levels and increase its side effects, so your care team may separate the doses, monitor you closely, or adjust your plan. Don't change either medicine on your own; talk with your pharmacist or doctor. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Danicopan 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 Danicopan and Relugolix interaction managed?
What your care team may do: Try to avoid using these two together when possible, or choose an alternative. 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. In some cases, relugolix may be paused for a short course of danicopan, then restarted (with the standard loading dose if the pause was longer than 7 d… 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 Danicopan 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 Danicopan
These medications also interact with supplements
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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