What the FDA labels say about taking them together
Efavirenz and levonorgestrel
Levonorgestrel's FDA label of January 31, 2023 names efavirenz in its warnings section; the efavirenz label PlainMeds reads does not name levonorgestrel. The levonorgestrel label: “… regular birth control Ask a doctor or pharmacist before use if you are taking efavirenz (HIV medication) or rifampin (tuberculosis treatment) or medication for seizures (epilepsy).”
Check it at the source: the efavirenz FDA label on DailyMed (effective March 31, 2024, Cipla USA Inc.); the levonorgestrel FDA label on DailyMed (effective January 31, 2023, Foundation Consumer Healthcare LLC).
What does the efavirenz label say about levonorgestrel?
Efavirenz's label (effective March 31, 2024) does not name levonorgestrel in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Efavirenz), Cipla USA Inc., effective March 31, 2024 (SPL set 92603fa5-7a2c-4bfb-9a70-aadb4fba952c), via openFDA; the full label on DailyMed
What does the levonorgestrel label say about efavirenz?
Levonorgestrel label, warningsWarnings Allergy alert Do not use if you have ever had an allergic reaction to levonorgestrel Sexually transmitted diseases (STDs) alert This product does not protect against HIV/AIDS or other STDs Do not use if you are already pregnant (because it will not work) for regular birth control Ask a doctor or pharmacist before use if you are taking efavirenz (HIV medication) or rifampin (tuberculosis treatment) or medication for seizures (epilepsy).
Source: FDA drug label (Plan B One-Step), Foundation Consumer Healthcare LLC, effective January 31, 2023 (SPL set 6ce6b40e-14ac-47bd-a648-ddf9e452e559), 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
| Efavirenz | Levonorgestrel | |
|---|---|---|
| Labeled for | HIV | Birth control |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $1.28 per tablet 600 mg tablet | $6.33 per tablet 1.5 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