Berkeley Life Nitric Oxide Saliva Test Strips were specifically designed to indicate salivary nitrite levels, a proven precursor to Nitric Oxide levels in the body. Use before and after a nitrate rich meal or supplement. This non-invasive saliva test checks Nitric Oxide production in under 15 seconds. With these strips, you can easily test at home to monitor progress. Simply use one test strip on the tongue to assess nitric oxide levels. Each tube has 50 individual testing strips. About Nitric Oxide: Nitric Oxide (NO) is a naturally produced molecule that plays a vital role in the circulation that supports almost every biological system. However, your body’s ability to produce NO declines rapidly as you age. Adequate Nitric Oxide levels are key to healthy vasodilation (relaxing of blood vessel walls), blood flow, and oxygen delivery. NO is also closely linked to supporting normal, healthy blood pressure levels and overall cardiovascular health — as well as energy levels, cognitive health, hormonal health, gut health, sexual health, and more.* By Age 40, Nitric Oxide Levels Drop by 50%