What the FDA labels say about taking them together
Ethinyl estradiol/segesterone and tizanidine
Ethinyl estradiol/segesterone's FDA label of April 23, 2025 names tizanidine in its drug interactions section; the tizanidine labels PlainMeds reads (3) do not name ethinyl estradiol/segesterone. The ethinyl estradiol/segesterone label: “Concomitant use with ethinyl estradiol-containing CHCs may increase systemic exposure of other drugs.”
Check it at the source: the ethinyl estradiol/segesterone FDA label on DailyMed (effective April 23, 2025); the tizanidine FDA label on DailyMed (effective January 2, 2026, Legacy Pharma USA, Inc.).
What does the ethinyl estradiol/segesterone label say about tizanidine?
Ethinyl estradiol/segesterone label, drug interactionsConcomitant use with ethinyl estradiol-containing CHCs may increase systemic exposure of other drugs (eg, cyclosporine, prednisolone, theophylline, tizanidine, and voriconazole).
Source: FDA drug label (Annovera), Mayne Pharma, effective April 23, 2025 (SPL set eb18194f-2021-41fa-8bdf-31e0c0eb646b), via openFDA; the full label on DailyMed
What does the tizanidine label say about ethinyl estradiol/segesterone?
Tizanidine's label (effective January 2, 2026) and its 2 other brand-application labels do not name ethinyl estradiol/segesterone in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Zanaflex), Legacy Pharma USA, Inc., effective January 2, 2026 (SPL set 60c27d35-7349-4fc6-86ad-70fffdbe3e08), 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
| Ethinyl estradiol/segesterone | Tizanidine | |
|---|---|---|
| Labeled for | Birth control | Muscle spasms and spasticity |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $2,315.29 per ring Annovera vaginal ring | $0.0331 per tablet 4 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