What the FDA labels say about taking them together
Carbamazepine and ethinyl estradiol/norelgestromin
Ethinyl estradiol/norelgestromin's FDA label of April 16, 2026 names carbamazepine in its drug interactions section; the carbamazepine labels PlainMeds reads (3) do not name ethinyl estradiol/norelgestromin. The ethinyl estradiol/norelgestromin label: “Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include phenytoin, barbiturates, carbamazepine, bosentan, felbamate, griseofulvin, oxcarbazepine, rifampicin, topiramate …”
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the ethinyl estradiol/norelgestromin FDA label on DailyMed (effective April 16, 2026, Zydus Pharmaceuticals USA Inc.).
What does the carbamazepine label say about ethinyl estradiol/norelgestromin?
Carbamazepine's label (effective August 20, 2026) and its 2 other brand-application labels do not name ethinyl estradiol/norelgestromin 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 ethinyl estradiol/norelgestromin label say about carbamazepine?
Ethinyl estradiol/norelgestromin label, drug interactionsSome drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include phenytoin, barbiturates, carbamazepine, bosentan, felbamate, griseofulvin, oxcarbazepine, rifampicin, topiramate, rifabutin, rufinamide, aprepitant, and products containing St. John's wort.
Gwyn Lo label (Viatris Specialty LLC, July 6, 2026), drug interactionsContinue backup contraception for 28 days after discontinuing the enzyme inducer to maintain contraceptive reliability. Examples Aprepitant, barbiturates, bosentan, carbamazepine, efavirenz, felbamate, griseofulvin, oxcarbazepine, phenytoin, rifampin, rifabutin, rufinamide, topiramate, products containing St. John’s wort, Induction potency of St. John’s wort may vary widely based on preparation. and certain protease inhibitors (see separate section on protease inhibitors below).
Source: FDA drug label (Gwyn Lo, NDA219990), Viatris Specialty LLC, effective July 6, 2026 (SPL set e92741f4-87fe-429f-b5b5-c558ed5f4fa9), via openFDA
Source: FDA drug label (norelgestromin and ethinyl estradiol), Zydus Pharmaceuticals USA Inc., effective April 16, 2026 (SPL set 10fa1458-c8ed-4197-922a-1ba7271d2b02), 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 | Ethinyl estradiol/norelgestromin | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Birth control |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.119 per tablet 200 mg tablet | $37.16 per patch 150-35 mcg/day patch |
| 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