Documented concern based on cited evidence — not a personalized safety check, not medical advice, and not a decision to combine or avoid. That decision belongs with your prescriber.

Documented concern — monitor and disclose

Clinically relevant documented concern. Disclose the supplement to your clinician and keep monitoring in place.

Mechanism and evidence

Both act on the nitric oxide-cGMP axis: PDE5 inhibitors keep cGMP up, citrulline raises NO production. Additive vasodilation can drop blood pressure more than either alone.

Evidence tier: meta-rct

The tier names the strongest cited study design. Some anchors studied the supplement on its own, or a related drug in the same class — in those pairs the grade rests on that evidence plus established pharmacology, as agreed with our medical reviewer.

What to discuss with your prescriber

  • Ask your prescriber before combining them; monitoring blood pressure during use was the reviewer requirement.
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← All reviewed pairs for PDE5 inhibitors (sildenafil, tadalafil, vardenafil, avanafil)