What the FDA labels say about taking them together
Efavirenz and lenacapavir
Lenacapavir's FDA label of August 27, 2026 names efavirenz in its drug interactions section; the efavirenz label PlainMeds reads does not name lenacapavir.
Check it at the source: the efavirenz FDA label on DailyMed (effective March 31, 2024, Cipla USA Inc.); the lenacapavir FDA label on DailyMed (effective August 27, 2026, Gilead Sciences, Inc.).
What does the efavirenz label say about lenacapavir?
Efavirenz's label (effective March 31, 2024) does not name lenacapavir 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 lenacapavir label say about efavirenz?
Lenacapavir label, drug interactionsConcomitant Drug Class/Drug Name: Antiretroviral Agents: atazanavir/cobicistat Drug-drug interaction study was conducted. atazanavir/ritonavir; Effect on Concentration ↑ = Increase, ↓ = Decrease.: ↑ lenacapavir (atazanavir/cobicistat, atazanavir/ritonavir); Clinical Comment: Concomitant administration of efavirenz, nevirapine, or tipranavir/ritonavir may result in loss of therapeutic effect and development of resistance.
Source: FDA drug label (Sunlenca), Gilead Sciences, Inc., effective August 27, 2026 (SPL set e5652804-29c4-40d7-aeb2-0142ed2a7b5b), 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 | Lenacapavir | |
|---|---|---|
| Labeled for | HIV | HIV |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $1.28 per tablet 600 mg tablet | n/a |
| 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