Estradiol and Darunavir: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Darunavir
No brand names on recordEstradiol
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.
What happens
Reduced hormonal contraceptives exposure, reduced efficacy of hormonal contraceptives and an increased darunavir exposure
Interaction Deep Dive
Combination oral contraceptives (COCs) have shown significant reduction in exposure of estrogen and/or progestin during coadministration with darunavir1. Consider supplementary or non-hormonal contraception options for women of childbearing potential during darunavir therapy. Concomitant use of darunavir and hormonal contraceptives (CYP3A4 inhibitors) may also increase exposure of darunavir 234.
Why it happens (mechanism)
Unknown; inhibition of CYP3A4-mediated metabolism of darunavir
Literature reports
1 report — tap to read
a) An open-label, randomized, crossover study in 19 healthy, HIV-negative females aged 18 to 43 years (median, 34 years) revealed that coadministration of ethinyl estradiol/norethindrone with darunavir/ritonavir resulted in significantly lower exposure and mean plasma concentrations of ethinyl estradiol and norethindrone. Compared to administration of ethinyl estradiol and norethindrone alone, coadministration with darunavir/ritonavir led to decreases in ethinyl estradiol Cmin, Cmax, and AUC of 62%, 32%, and 44%, respectively. Similarly, norethindrone Cmin, Cmax, and AUC decreased by 30%, 10%, and 14%, respectively. There were no significant changes in darunavir or ritonavir pharmacokinetic parameters 5.
Common questions
Can I take Estradiol and Darunavir together?
Reduced hormonal contraceptives exposure, reduced efficacy of hormonal contraceptives and an increased darunavir exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Estradiol and Darunavir 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 strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Estradiol or Darunavir 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 (5)
- Product Information: LOESTRIN(R) 24 Fe oral tablets, norethindrone acetate ethinyl estradiol oral tablets, ferrous fumarate oral tablets. Teva Pharmaceuticals USA Inc (per FDA), Parsippany, NJ, 2023. DailyMed
- Product Information: PREZCOBIX® PED oral tablets for suspension, darunavir cobicistat oral tablets for suspension. Janssen Products, LP (per FDA), Horsham, PA, 2026. DailyMed
- Product Information: PREZCOBIX® oral tablets, darunavir cobicistat oral tablets. Janssen Products, LP (per FDA), Horsham, PA, 2026. DailyMed
- Product Information: PREZISTA(R) oral suspension, oral tablets, darunavir oral suspension, oral tablets. Janssen Products, LP (per FDA), Horsham, PA, 2023. DailyMed
- Sekar VJ, Lefebvre E, Guzman SS, et al: Pharmacokinetic interaction between ethinyl estradiol, norethindrone and darunavir with low-dose ritonavir in healthy women. Antivir.Ther 2008; 13(4):563-569. DOI
Keep reading about Darunavir
Keep reading about Estradiol
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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