Relugolix and Tezacaftor: 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
Tezacaftor
No brand names on record
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 cleared from your body partly by a little "pump" in your gut called P-gp. Tezacaftor can slow that pump down. When the pump slows, more relugolix stays in your body, so its levels can climb higher than intended.
Higher relugolix levels can mean more of its usual side effects, like hot flashes, tiredness, or diarrhea. The good news is this is very manageable. Please don't stop or change either medicine on your own. Just let your pharmacist or doctor know you take both, and they can space out the timing, watch you a bit more closely, or adjust things to keep you safe.
Mechanism/direction: Relugolix is a P-gp substrate; tezacaftor can inhibit intestinal P-gp efflux, reducing relugolix clearance and increasing its systemic exposure (higher AUC/Cmax). Neither drug is a prodrug here, so the effect is straightforward accumulation of relugolix.
- Magnitude: With a known P-gp inhibitor (erythromycin), relugolix AUC rose ~3.5-fold and Cmax ~2.9-fold; tezacaftor magnitude not specifically quantified.
- Evidence/onset: Probable; onset unspecified. Severity: major.
- Management: Avoid coadministration if possible. If unavoidable, give relugolix first, separate by at least 6 hours, and monitor more frequently for relugolix adverse effects.
What happens
Increased relugolix exposure
Interaction Deep Dive
Do not use relugolix (a P-gp substrate) together with P-gp inhibitors, because this combination can raise relugolix exposure and thereby heighten the likelihood 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. Once the P-gp inhibitor has been stopped, relugolix can be resumed. Should relugolix be held for more than 7 days, restart it using a 360 mg loading dose on the first day, then continue at 120 mg once daily. 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 two together when possible.
- If both are needed, have you take relugolix first and separate the two doses by at least 6 hours.
- Monitor you more closely for relugolix side effects (such as hot flashes, fatigue, or diarrhea).
- In some cases, briefly pause relugolix during a short course of the other drug and restart afterward, sometimes with a loading dose if the pause is long.
What you should do: Keep taking both exactly as prescribed for now, and tell your pharmacist or prescriber that you use both so they can tailor timing and monitoring for you.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) A drug interaction study found that 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 Relugolix and Tezacaftor together?
Tezacaftor can raise relugolix levels and side effects by slowing a gut transporter; keep taking both as prescribed but tell your pharmacist or doctor so they can space the doses (relugolix first, at least 6 hours apart) and watch you more closely. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Tezacaftor 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 Tezacaftor interaction managed?
What your care team may do: Try to avoid using these two together when possible. If both are needed, have you take relugolix first and separate the two doses by at least 6 hours. Monitor you more closely for relugolix side effects (such as hot flashes, fatigue, or diarrhea). In some cases, briefly pause relugolix during a short course of the other drug and restart afterward, sometimes with a loadi… 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 Tezacaftor 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 Tezacaftor
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.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist