Nitric Oxide in Plasma (Endothelial-Derived Nitric Oxide)

Why This Test Might Be Ordered

Your healthcare provider may order this test to evaluate endothelial function, assess vascular health, or investigate symptoms like peripheral neuropathy, erectile dysfunction, or unexplained low blood pressure. It may also be used in research or specialized clinical studies focused on nitric oxide metabolism.

How the Test Works

Blood is drawn and processed to separate plasma, where nitric oxide levels are measured using a specialized chemical reaction that detects its presence. The test does not require fasting and is typically completed within hours of collection.

Sample Preparation and Specimen

This test uses plasma from a blood draw. Plasma is the liquid part of blood after clotting factors are removed. You may be asked to avoid certain medications (e.g., nitrates) that could affect nitric oxide levels for a short period before testing.

What to Expect Before the Test

No special preparation is usually needed, but inform your provider about any medications you’re taking, especially those affecting blood pressure or circulation. Avoid strenuous activity or exposure to extreme temperatures before your blood draw.