You can increase nitric oxide through two main pathways: eating nitrate-rich foods that your body converts into nitric oxide, and supporting the enzyme in your blood vessels that produces it directly. Both pathways respond well to straightforward diet and lifestyle changes, and the effects are measurable within hours.
How Your Body Makes Nitric Oxide
Your body produces nitric oxide through two distinct routes, and understanding both helps explain why different strategies work.
The first is an enzyme in the lining of your blood vessels that converts the amino acid L-arginine into nitric oxide and a byproduct called L-citrulline. This enzyme responds to physical triggers like blood flow and shear stress, which is why exercise is such a reliable way to boost production. Anything that keeps blood vessel linings healthy supports this pathway.
The second route is the nitrate-nitrite-nitric oxide pathway. When you eat nitrate-rich vegetables, bacteria on your tongue convert the nitrate into nitrite. That nitrite then gets further reduced to nitric oxide in your stomach and bloodstream. This pathway works independently of the enzyme in your blood vessels, which makes it especially useful for older adults or anyone whose blood vessel function has declined.
Eat More Nitrate-Rich Vegetables
Dietary nitrate is the most direct and well-studied way to raise nitric oxide levels through food. The vegetables with the highest nitrate concentrations per 100 grams are radish (625 mg), beetroot (495 mg), tarragon (424 mg), lettuce (365 mg), mint (279 mg), and celery (261 mg). Beetroot gets the most attention in research, but several leafy greens and root vegetables deliver comparable or higher amounts.
Research published by the American Heart Association tested specific nitrate doses in healthy volunteers. A single 250 mL serving of beetroot juice, containing roughly 340 mg of nitrate, lowered systolic blood pressure by an average of 5.4 mmHg. A higher dose of about 1,500 mg of nitrate (from capsules) produced a peak reduction of 9.4 mmHg in systolic blood pressure at six hours, with effects lasting over 24 hours. The response was dose-dependent, meaning more nitrate produced a bigger effect up to a point.
You don’t need to drink beetroot juice specifically. A large salad with arugula, spinach, and radishes can deliver a meaningful nitrate dose. Cooking reduces nitrate content somewhat, so raw or lightly prepared vegetables retain more. The key is consistency: making high-nitrate vegetables a regular part of your meals rather than an occasional addition.
Don’t Kill Your Oral Bacteria
Here’s something most people don’t realize: the nitrate-to-nitric-oxide pathway depends entirely on bacteria living on your tongue. Without them, the nitrate from your beet salad never gets converted into nitrite, and the whole chain stalls.
Antiseptic mouthwash, particularly chlorhexidine-based products, kills these nitrate-reducing bacteria. Research shows that chlorhexidine mouthwash reduces oral bacteria populations and decreases the nitrate-processing enzyme activity on the tongue. One study found that mouthwash actually blocked the blood-pressure-lowering effects of L-arginine supplementation entirely. If you’re eating nitrate-rich foods to boost nitric oxide, using antibacterial mouthwash regularly works against you. Switching to a non-antibacterial mouthwash or simply brushing and flossing without mouthwash preserves this bacterial community.
L-Citrulline Outperforms L-Arginine
Since the blood vessel enzyme uses L-arginine as its raw material, supplementing with L-arginine seems like an obvious move. In practice, it’s less effective than you’d expect. When you take L-arginine orally, enzymes in your gut and liver break down a large portion of it before it ever reaches your bloodstream. This limits how much actually becomes available for nitric oxide production.
L-citrulline, an amino acid found in watermelon, sidesteps this problem. Your kidneys convert citrulline into arginine, bypassing the gut and liver breakdown. Studies in healthy volunteers show that L-citrulline supplementation raises blood arginine levels more effectively than taking the same dose of L-arginine directly. For supplementation purposes, L-citrulline (typically 3 to 6 grams daily) is the better choice. Watermelon is the richest food source, though you’d need to eat quite a lot to match supplement doses.
Protect Nitric Oxide With Antioxidants
Nitric oxide is fragile. It reacts almost instantly with free radicals in your bloodstream, which means your body can produce plenty of it and still not get the full benefit if oxidative stress is high. This is where antioxidants come in.
Vitamin C (ascorbic acid) plays a particularly important role. It’s the plasma antioxidant most affected by peroxynitrite, a damaging compound that forms when nitric oxide reacts with certain oxygen radicals. By neutralizing peroxynitrite, vitamin C helps preserve nitric oxide before it gets destroyed. Research from the American Heart Association shows that nitric oxide and vitamin E together are actually more efficient at preventing oxidative damage than the classic vitamin C and vitamin E pairing. Nitric oxide protects vitamin E from being used up, and vitamin E in turn helps maintain vascular health. Eating a diet rich in fruits, vegetables, nuts, and seeds provides these antioxidants naturally and creates an environment where the nitric oxide your body produces lasts longer and does more.
Get Sunlight on Your Skin
Your skin stores nitric oxide in inactive forms, including nitrite and compounds called S-nitrosothiols. When UVA light from the sun hits your skin, it breaks these compounds apart and releases active nitric oxide. Some of that nitric oxide diffuses into the capillaries beneath the skin, enters the bloodstream as stable carrier molecules, and produces system-wide effects like lower blood pressure.
A study in Circulation Research measured this process directly. After 20 joules per square centimeter of UVA exposure (equivalent to roughly 45 minutes of sun in a temperate climate), participants showed increased circulating nitric oxide metabolites and a measurable drop in blood pressure. This effect is completely independent of vitamin D production, which is triggered by UVB light instead. Even brief, regular sun exposure on your arms and face contributes to this reservoir effect. Sunscreen blocks UVA to varying degrees, so there’s a practical tradeoff between skin protection and nitric oxide release that depends on your individual risk factors.
Exercise Activates the Enzyme Directly
Physical activity is one of the most reliable triggers for nitric oxide production. When your heart rate increases, blood moves faster through your vessels, creating shear stress on the vessel lining. This mechanical force activates the enzyme that converts L-arginine into nitric oxide. The result is vasodilation: your blood vessels widen, blood pressure drops, and blood flow to muscles and organs increases.
Both aerobic exercise and resistance training stimulate this pathway, though aerobic exercise produces a more sustained effect on blood vessel function. The benefits are cumulative. Regular exercise improves the health of your blood vessel lining over time, making the enzyme more responsive and increasing baseline nitric oxide availability. Even a brisk 30-minute walk generates meaningful shear stress. The boost in nitric oxide production is one reason blood pressure tends to drop for several hours after a workout.
Putting It Together
The most effective approach combines multiple strategies that target different pathways simultaneously. A plate of high-nitrate vegetables provides raw material for the oral bacteria pathway. Regular exercise and adequate L-citrulline keep the blood vessel enzyme pathway active. Antioxidant-rich foods protect the nitric oxide once it’s produced. Time outside in natural sunlight taps into your skin’s stored reserves. And skipping the antibacterial mouthwash keeps the whole system from being undermined at the first step. None of these changes are dramatic on their own, but stacked together they address every major bottleneck in how your body makes, preserves, and uses nitric oxide.