What the FDA labels say about taking them together
Carbamazepine and estradiol
Estradiol's FDA label of April 3, 2024 names carbamazepine in its drug interactions section; the carbamazepine labels PlainMeds reads (3) do 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 carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the estradiol FDA label on DailyMed (effective April 3, 2024, Amneal Pharmaceuticals LLC).
What does the carbamazepine label say about estradiol?
Carbamazepine's label (effective August 20, 2026) and its 2 other brand-application labels do 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 (Tegretol), Novartis Pharmaceuticals Corporation, effective August 20, 2026 (SPL set 8d409411-aa9f-4f3a-a52c-fbcb0c3ec053), via openFDA; the full label on DailyMed
What does the estradiol label say about carbamazepine?
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
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
| Carbamazepine | Estradiol | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Menopause symptoms, Breast cancer, Osteoporosis |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.119 per tablet 200 mg tablet | $0.0635 per tablet 1 mg tablet |
| Shortage now | A presentation being discontinued | No current entry |
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