What the FDA labels say about taking them together
Bosentan and norethindrone
Bosentan's FDA label of November 17, 2025 names norethindrone in its drug interactions section, and norethindrone's label names bosentan too. The bosentan label: “An interaction study demonstrated that co-administration of bosentan and a combination oral hormonal contraceptive produced average decreases of norethindrone and ethinyl estradiol levels of 14% and 31%, respectively.”
Check it at the source: the bosentan FDA label on DailyMed (effective November 17, 2025, Actelion Pharmaceuticals US, Inc.); the norethindrone FDA label on DailyMed (effective January 31, 2026, Glenmark Pharmaceuticals Inc., USA).
What does the bosentan label say about norethindrone?
Bosentan label, drug interactionsAn interaction study demonstrated that co-administration of bosentan and a combination oral hormonal contraceptive produced average decreases of norethindrone and ethinyl estradiol levels of 14% and 31%, respectively.
Source: FDA drug label (Tracleer), Actelion Pharmaceuticals US, Inc., effective November 17, 2025 (SPL set 749e42fb-2fe0-45dd-9268-b43bb3f4081c), via openFDA; the full label on DailyMed
What does the norethindrone label say about bosentan?
Norethindrone label, drug interactionsSome drugs or herbal products that may decrease the effectiveness of HCs include efavirenz, phenytoin, barbiturates, carbamazepine, bosentan, felbamate, griseofulvin, oxcarbazepine, rifampicin, rifabutin, rufinamide, aprepitant, and products containing St. John’s wort.
Source: FDA drug label (Norethindrone), Glenmark Pharmaceuticals Inc., USA, effective January 31, 2026 (SPL set 0d2f8fea-3675-40d2-afd9-9fcb148dbd4b), 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
| Bosentan | Norethindrone | |
|---|---|---|
| Labeled for | Pulmonary arterial hypertension | Birth control |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | n/a | $0.290 per tablet 5 mg tablet |
| Shortage now | No current entry | 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