What the FDA labels say about taking them together
Estradiol and rifampin
Estradiol's FDA label of April 3, 2024 names rifampin in its drug interactions section; the rifampin label PlainMeds reads does not name estradiol. The estradiol label: “Inducers of CYP3A4, such as St. John’s wort ( Hypericum perforatum ) preparations, phenobarbital, carbamazepine and rifampin, may reduce plasma concentrations of estrogens, possibly resulting in a decrease in …”
Check it at the source: the estradiol FDA label on DailyMed (effective April 3, 2024, Amneal Pharmaceuticals LLC); the rifampin FDA label on DailyMed (effective February 11, 2026, Lupin Pharmaceuticals, Inc.).
What does the estradiol label say about rifampin?
Estradiol label, drug interactionsInducers of CYP3A4, such as St. John’s wort ( Hypericum perforatum ) preparations, phenobarbital, carbamazepine and rifampin, may reduce plasma concentrations of estrogens, possibly resulting in a decrease in therapeutic effects and/or changes in the uterine bleeding profile.
Source: FDA drug label (YUVAFEM), Amneal Pharmaceuticals LLC, effective April 3, 2024 (SPL set 30c7f6ba-7a9e-4853-b3e4-e00a46560224), via openFDA; the full label on DailyMed
What does the rifampin label say about estradiol?
Rifampin's label (effective February 11, 2026) does not name estradiol in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (rifampin), Lupin Pharmaceuticals, Inc., effective February 11, 2026 (SPL set b56004f0-f23d-47f6-80c7-39884fccbccc), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Estradiol | Rifampin | |
|---|---|---|
| Labeled for | Menopause symptoms, Breast cancer, Osteoporosis | n/a |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.0635 per tablet 1 mg tablet | $0.679 per capsule 300 mg capsule |
| Shortage now | No current entry | In shortage |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once