If "nitric oxide" makes you think of the laughing gas at the dentist, you're in good company, but that's nitrous oxide, a different molecule. Nitric oxide is something your own body makes, and it's one of the most important signaling molecules you have. It helps your blood vessels relax, keeps blood flowing to your muscles and brain, and plays a part in how well you exercise. Here's what it does and how to support it with food and movement.
What is nitric oxide?
Nitric oxide (NO) is a small gas molecule produced by the endothelium, the thin layer of cells lining your blood vessels. When it's released, the muscle in the vessel wall relaxes, the vessel widens and blood flows more easily.
Your body makes nitric oxide in two ways. The classic route builds it from the amino acid L-arginine. A second route, discovered more recently, turns nitrate from your diet into nitrite and then nitric oxide, with help from bacteria in your mouth. That second pathway is why vegetables matter so much, and it gives you a practical lever to pull.
Why is nitric oxide important for your health?
Healthy blood flow and blood pressure
Nitric oxide's best-known job is keeping blood vessels relaxed and flexible. Dietary nitrate, through its conversion to nitric oxide, has been shown to lower blood pressure, reduce platelet stickiness and support the function of the blood vessel lining. That matters because heart disease is the leading cause of death for both men and women in the US.
Exercise performance
Better blood flow means more oxygen reaching working muscles. In a meta-analysis of 80 studies, nitrate supplements produced a small but consistent improvement in exercise performance in recreationally active men. The effect was less clear in women and in highly trained endurance athletes.
The brain
Nitric oxide also acts as a messenger in the nervous system, and blood flow to the brain matters for how it works. In one small trial, older adults who drank beetroot juice before exercising for six weeks developed brain network patterns that more closely resembled those of younger adults than those who exercised without it. It's an early finding, but an intriguing one.
How does exercise boost nitric oxide?
When you start moving, your heart pumps harder and blood rushes through your vessels. The drag of that flow along the vessel wall, called shear stress, is a major signal for the endothelium to release nitric oxide. Over time, regular aerobic and resistance training both tend to improve how well your blood vessels respond, which is one more reason exercise is so good for your heart.
Which foods help your body make nitric oxide?
Food supports both pathways:
- Nitrate-rich vegetables. Leafy vegetables such as arugula and spinach are the richest plant sources of nitrate, and beets are another good one. In a meta-analysis of 16 trials, nitrate and beetroot juice lowered systolic blood pressure by about 4.4 mmHg.
- Foods with L-arginine. Protein-rich foods such as nuts, seeds and legumes supply the amino acid used in the classic pathway.
- Foods with L-citrulline. Watermelon is a rich source of this amino acid, which the body can convert to arginine.
For a full shopping list, see our top 10 nitric oxide foods.
One surprising tip: go easy on antiseptic mouthwash. Because mouth bacteria do the first step of converting nitrate, using a strong antiseptic mouthwash for a week cut oral nitrite production by 90% and nudged blood pressure up in healthy volunteers.
Can a pre-workout support nitric oxide?
Many pre-workouts now include nitrate-rich plants for exactly this reason. Renewable Energy includes organic beetroot and pomegranate juice powders alongside 90mg of caffeine from organic green coffee bean, matcha and yerba mate and an adaptogen blend of ashwagandha, rhodiola, ginseng and maca. Renewable Energy Plus pairs the same beetroot and pomegranate with 180mg of caffeine. If you're comparing options, our guide on how to choose the best pre-workout explains what else to look for.
If you take medication for blood pressure or a heart condition, talk to your doctor before adding concentrated nitrate products such as beetroot supplements. For most people, though, the advice is simple: move every day, and fill your plate with leafy greens and beets.
