What the FDA labels say about taking them together
Sepiapterin and tadalafil
Sepiapterin's FDA label of April 24, 2026 names tadalafil in its drug interactions section; the tadalafil labels PlainMeds reads (3) do not name sepiapterin. The sepiapterin label: “Monitor for signs and symptoms of hypotension with concomitant use of SEPHIENCE with drugs that affect nitric oxide-mediated vasorelaxation.”
Check it at the source: the sepiapterin FDA label on DailyMed (effective April 24, 2026, PTC Therapeutics Inc.); the tadalafil FDA label on DailyMed (effective June 3, 2026, Eli Lilly and Company).
What does the sepiapterin label say about tadalafil?
Sepiapterin label, drug interactionsMonitor for signs and symptoms of hypotension with concomitant use of SEPHIENCE with drugs that affect nitric oxide-mediated vasorelaxation (e.g., PDE-5 inhibitors such as sildenafil, vardenafil, or tadalafil).
Source: FDA drug label (Sephience), PTC Therapeutics Inc., effective April 24, 2026 (SPL set 32ac719c-49f0-4105-9c46-18c19583a5c2), via openFDA; the full label on DailyMed
What does the tadalafil label say about sepiapterin?
Tadalafil's label (effective June 3, 2026) and its 2 other brand-application labels do not name sepiapterin in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Cialis), Eli Lilly and Company, effective June 3, 2026 (SPL set bcd8f8ab-81a2-4891-83db-24a0b0e25895), 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
| Sepiapterin | Tadalafil | |
|---|---|---|
| Labeled for | n/a | Erectile dysfunction, Enlarged prostate (BPH), Pulmonary arterial hypertension |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $0.167 per tablet 20 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