What the FDA labels say about taking them together
Lenacapavir and sildenafil
Lenacapavir's FDA label of August 27, 2026 names sildenafil in its drug interactions section; the sildenafil labels PlainMeds reads (4) do not name lenacapavir. The lenacapavir label: “Use of PDE-5 inhibitors for pulmonary arterial hypertension (PAH): Concomitant administration of SUNLENCA with tadalafil for the treatment of PAH is not recommended. …”
Check it at the source: the lenacapavir FDA label on DailyMed (effective August 27, 2026, Gilead Sciences, Inc.); the sildenafil FDA label on DailyMed (effective November 17, 2023, Viatris Specialty LLC).
What does the lenacapavir label say about sildenafil?
Lenacapavir label, drug interactionsConcomitant Drug Class/Drug Name: Phosphodiesterase-5 (PDE-5) Inhibitors: sildenafil tadalafil vardenafil; Effect on Concentration ↑ = Increase, ↓ = Decrease.: ↑ PDE-5 inhibitors; Clinical Comment: Use of PDE-5 inhibitors for pulmonary arterial hypertension (PAH): Concomitant administration of SUNLENCA with tadalafil for the treatment of PAH is not recommended. Use of PDE-5 inhibitors for erectile dysfunction (ED): Refer to the prescribing information of PDE-5 inhibitors for dose recommendations.
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
What does the sildenafil label say about lenacapavir?
Sildenafil's label (effective November 17, 2023) and its 3 other brand-application labels do 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 (Viagra), Viatris Specialty LLC, effective November 17, 2023 (SPL set d905dc8d-917f-4ea3-a4ee-a1ecf6967d4e), 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
| Lenacapavir | Sildenafil | |
|---|---|---|
| Labeled for | HIV | Erectile dysfunction, Pulmonary arterial hypertension |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $0.132 per tablet 100 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