Vibegron 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
Vibegron
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. Vibegron (Gemtesa) can slow that pump down. When the pump is slowed, more relugolix stays in your body, so the level goes up. That means you could feel more of relugolix's side effects, like hot flashes, fatigue, or joint aches.
Please don't change anything on your own. This is a well-known combination your care team can manage, often by spacing the doses out and keeping a closer eye on how you feel. Just let your pharmacist or doctor know you take both.
Effect: Increased relugolix exposure via inhibition of P-gp mediated efflux. Relugolix is a P-gp substrate; vibegron can inhibit intestinal P-gp, raising relugolix AUC and Cmax and the risk of relugolix-related adverse effects. Neither drug's active effect depends on metabolic activation.
Magnitude: Not quantified for vibegron specifically; a study with erythromycin (P-gp inhibitor) raised relugolix AUC 3.5-fold and Cmax 2.9-fold. Evidence: probable. Severity: major.
Management:
- Avoid concomitant use where possible.
- If unavoidable, give relugolix first and separate by at least 6 hours.
- Monitor for relugolix adverse reactions more frequently.
- If relugolix is held >7 days, restart with 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 relugolix-related adverse reactions. When such combined use cannot be avoided, give relugolix or relugolix/estradiol/norethindrone acetate first, allow a gap of no less than 6 hours between doses, and increase how often adverse reactions are monitored 12. For a brief course of certain P-gp inhibitors, relugolix therapy may be paused for as long as 2 weeks, resuming once the P-gp inhibitor has been stopped. Should the interruption of relugolix last longer than 7 days, restart it using a 360 mg loading dose on day one, followed by 120 mg once daily thereafter. A drug interaction study demonstrated that giving relugolix (P-gp substrate) together with erythromycin (P-gp inhibitor) raised relugolix AUC by 3.5-fold and Cmax by 2.9-fold 1.
Why it happens (mechanism)
Inhibition of P-gp-mediated efflux transport of relugolix
How to manage this interaction
Keep taking both exactly as prescribed unless your prescriber tells you otherwise. This combination can be managed.
Here is what a care team typically does:
- They may try to avoid using the two together when another option works.
- If both are needed, they often have you take relugolix first and separate the doses by at least 6 hours.
- They may monitor you more closely for relugolix side effects.
- If relugolix was paused for a short time, they will restart it and individualize your dose (a loading dose may be used).
Tell your pharmacist or doctor you take both so they can tailor your plan.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In a study evaluating drug interactions, 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 Vibegron and Relugolix together?
Vibegron can raise relugolix levels by slowing the P-gp pump that clears it, which may increase relugolix side effects. Your care team can manage this by separating the doses and watching you more closely, so let your pharmacist or doctor know you take both. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Vibegron 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 Vibegron and Relugolix interaction managed?
Keep taking both exactly as prescribed unless your prescriber tells you otherwise. This combination can be managed. Here is what a care team typically does: They may try to avoid using the two together when another option works. If both are needed, they often have you take relugolix first and separate the doses by at least 6 hours. They may monitor you more closely for relugolix side effects. If r… 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 Vibegron 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 Vibegron
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