Relugolix and Vilazodone: 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
Vilazodone
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.
You've been prescribed vilazodone (Viibryd), an antidepressant, along with relugolix (Orgovyx). The concern here is that vilazodone can slow down a natural "pump" in your body called P-gp that normally helps move relugolix out. When that pump is blocked, more relugolix can build up in your system.
More relugolix means a higher chance of its side effects, like hot flashes, tiredness, or other reactions. The good news is your care team knows how to handle this. They may adjust the timing of your doses, watch you a little more closely, or choose another option. Don't stop or change either medicine on your own, just check in with your pharmacist or doctor.
Effect: Vilazodone may inhibit P-gp-mediated efflux of relugolix (a P-gp substrate), increasing relugolix exposure (AUC/Cmax) and the risk of relugolix-associated adverse reactions. For reference, erythromycin (a known P-gp inhibitor) raised relugolix AUC 3.5-fold and Cmax 2.9-fold.
- Direction: increased relugolix effect/toxicity
- Evidence: probable; severity major
- Onset: unspecified
Management: Avoid concomitant use if possible. If unavoidable, give relugolix first, separate by at least 6 hours, and monitor more frequently for adverse reactions. Short courses of a P-gp inhibitor may warrant relugolix interruption (up to 2 weeks); 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 it can raise relugolix exposure and thereby heighten the risk 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 interrupted for more than 7 days, it should be restarted using a loading dose of 360 mg on the first day, 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 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
This combination is best avoided when possible, but your care team can manage it safely if you need both.
- Keep taking both exactly as prescribed unless your prescriber tells you otherwise.
- Your team may have you take relugolix first and separate the two medicines by at least 6 hours.
- They may monitor you more closely for relugolix side effects such as hot flashes, fatigue, or other reactions.
- In some cases relugolix may be paused during a short course of the interacting drug, then restarted (sometimes with a loading dose) under their guidance.
Ask your pharmacist or doctor before making any change, and report new or worsening symptoms.
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 of relugolix by 3.5-fold and its Cmax by 2.9-fold 1.
Common questions
Can I take Relugolix and Vilazodone together?
Vilazodone can raise relugolix levels by blocking its P-gp pump, increasing side-effect risk; avoid combining if possible, and if not, separate doses by at least 6 hours and let your care team monitor you more closely. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Vilazodone 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 Vilazodone interaction managed?
This combination is best avoided when possible, but your care team can manage it safely if you need both. Keep taking both exactly as prescribed unless your prescriber tells you otherwise. Your team may have you take relugolix first and separate the two medicines by at least 6 hours. They may monitor you more closely for relugolix side effects such as hot flashes, fatigue, or other reactions. In s… 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 Vilazodone 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 Vilazodone
Keep reading about Relugolix
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major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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