Drug Interaction Report

Relugolix and Venetoclax: 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

Venetoclax

Venclexta Venclexta®
+

Relugolix

Orgovyx Orgovyx®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Updated Jul 2, 2026
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
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.

Of 340 documented Relugolix interactions, 313 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
At a glance + Effects may be stronger
The Bottom Line
Venetoclax can raise relugolix levels and its side effects by blocking a transporter; your care team may avoid the combination, separate doses by at least 6 hours, or monitor you more closely. Keep taking both as prescribed and check with your pharmacist or doctor.

Here's what's going on: Venetoclax can block a protein pump (called P-gp) that normally helps move relugolix out of your body. When that pump is slowed down, more relugolix stays in your system. In a study using a similar blocker, relugolix levels rose about 3 times higher.

More relugolix in your body can mean a higher chance of its side effects, like hot flashes, tiredness, or changes in blood pressure. The good news is that this is very manageable. Your care team can adjust timing, watch you more closely, or make other changes. Please don't stop or change either medicine on your own, just talk with your pharmacist or doctor.

Mechanism: Venetoclax inhibits P-gp mediated efflux of relugolix (a P-gp substrate), increasing relugolix exposure. Neither drug is a prodrug, so this is a straightforward increase in relugolix effect.

  • Direction/magnitude: Increased relugolix AUC/Cmax; a reference P-gp inhibitor (erythromycin) raised AUC 3.5-fold and Cmax 2.9-fold.
  • Evidence: Probable; severity major.
  • Management: Avoid concomitant use if possible. If unavoidable, give relugolix first and separate dosing by at least 6 hours, and monitor for relugolix adverse reactions more frequently. 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 once daily.
Onset
unspecified
Evidence
probable
Severity
Major

What happens

Increased relugolix exposure

Interaction Deep Dive

The simultaneous 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 adverse reactions linked to relugolix. When coadministration cannot be avoided, give relugolix or relugolix/estradiol/norethindrone acetate first, allow at least 6 hours between the 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. Relugolix should be resumed once the P-gp inhibitor has been stopped. Should relugolix therapy be paused for more than 7 days, reinitiate relugolix using a 360 mg loading dose on day one, followed by 120 mg once daily thereafter. A drug interaction study showed that giving relugolix (P-gp substrate) together with erythromycin (P-gp inhibitor) produced a 3.5-fold rise in relugolix AUC and a 2.9-fold rise in Cmax 1.

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 doses by at least 6 hours.
  • Watch you more closely for relugolix side effects.
  • In some cases, relugolix may be paused during a short course of the other drug and restarted afterward (with a loading dose if paused more than 7 days).

What you should do: Keep taking both exactly as prescribed unless your team tells you otherwise. Ask your pharmacist or prescriber how to space your doses and what side effects to watch for.

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's AUC by 3.5-fold and its Cmax by 2.9-fold 1.

Common questions

Can I take Relugolix and Venetoclax together?

Venetoclax can raise relugolix levels and its side effects by blocking a transporter; your care team may avoid the combination, separate doses by at least 6 hours, or monitor you more closely. Keep taking both as prescribed and check with your pharmacist or doctor. Always confirm with your pharmacist or prescriber before making any change.

How serious is the Relugolix and Venetoclax 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 Venetoclax 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 doses by at least 6 hours. Watch you more closely for relugolix side effects. In some cases, relugolix may be paused during a short course of the other drug and restarted afterward (with a loading dose if paused more than 7 days). What… 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 Venetoclax 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)

  1. Product Information: ORGOVYX oral tablets, relugolix oral tablets. Sumitomo Pharma America, Inc (per FDA), Marlborough, MA, 2025. DailyMed
  2. Product Information: MYFEMBREE(R) oral tablets, relugolix, estradiol, norethindrone acetate oral tablets. Myovant Sciences Inc (per FDA), Brisbane, CA, 2021. DailyMed
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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.