Educational reference of documented concerns — not a personalized safety check and not a clearance to combine. Confirm with your prescriber or pharmacist.
Reviewed supplements
- ModeratePDE5 inhibitors (sildenafil, tadalafil, vardenafil, avanafil)L-citrulline Both act on the nitric oxide-cGMP axis: PDE5 inhibitors keep cGMP up, citrulline raises NO production. 2 PMIDsverified 2026-08-18
- ModeratePDE5 inhibitors (sildenafil, tadalafil, vardenafil, avanafil)L-arginine Same NO-cGMP pathway as citrulline; meta-analyses show the combination has been studied under supervision, but self-directed stacking carries additive hypotension risk. 1 PMIDverified 2026-08-18
Not in this list
A supplement missing from this list has not been reviewed against PDE5 inhibitors (sildenafil, tadalafil, vardenafil, avanafil) on this site. That is not a statement that combining it is safe.