What the FDA labels say about taking them together
Mycophenolic acid and valacyclovir
Mycophenolic acid's FDA label of July 29, 2026 names valacyclovir in its drug interactions section; the valacyclovir label PlainMeds reads does not name mycophenolic acid. The mycophenolic acid label: “Acyclovir (Valacyclovir), Ganciclovir (Valganciclovir), and Other Drugs That Undergo Renal Tubular Secretion The coadministration of MMF and acyclovir or ganciclovir may increase plasma concentrations of mycophenolic …”
Check it at the source: the mycophenolic acid FDA label on DailyMed (effective July 29, 2026, Novartis Pharmaceuticals Corporation); the valacyclovir FDA label on DailyMed (effective November 12, 2025, GlaxoSmithKline LLC).
What does the mycophenolic acid label say about valacyclovir?
Mycophenolic acid label, drug interactionsAcyclovir (Valacyclovir), Ganciclovir (Valganciclovir), and Other Drugs That Undergo Renal Tubular Secretion The coadministration of MMF and acyclovir or ganciclovir may increase plasma concentrations of mycophenolic acid glucuronide (MPAG) and acyclovir/valacyclovir/ganciclovir/valganciclovir as their coexistence competes for tubular secretion.
Source: FDA drug label (Myfortic), Novartis Pharmaceuticals Corporation, effective July 29, 2026 (SPL set eed26501-890d-4ff6-88e7-6dbea4726e53), via openFDA; the full label on DailyMed
What does the valacyclovir label say about mycophenolic acid?
Valacyclovir's label (effective November 12, 2025) does not name mycophenolic acid in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (VALTREX), GlaxoSmithKline LLC, effective November 12, 2025 (SPL set f8e0d8f8-cb73-4206-a484-88f5c4fbd719), 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
| Mycophenolic acid | Valacyclovir | |
|---|---|---|
| Labeled for | Organ transplant rejection | Herpes and shingles |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.0996 per tablet 180 mg tablet | $0.229 per tablet 500 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