How to Increase Nitric Oxide Naturally: 7 Ways

Nitric oxide is a signaling molecule your body uses to relax blood vessels, improve blood flow, and support everything from cardiovascular health to exercise performance. Your body makes it in two main ways: through an enzyme in the lining of your blood vessels, and through a dietary pathway that converts nitrate from food into nitrite and then into nitric oxide. Both pathways are influenced by everyday habits, and several of them are surprisingly simple to change. Here are seven evidence-backed ways to support your body’s nitric oxide production without supplements or medications you don’t need.

Eat Nitrate-Rich Vegetables

The most studied dietary strategy for boosting nitric oxide is eating vegetables high in inorganic nitrate, and beetroot is the poster child. When you eat nitrate-rich foods, bacteria on your tongue convert some of the nitrate to nitrite. That nitrite enters your bloodstream and gets further reduced to nitric oxide throughout the body. This is sometimes called the nitrate-nitrite-NO pathway, and it works independently of the enzyme-driven system in your blood vessel walls.¹

A systematic review found that beetroot juice supplementation can lower blood pressure across different populations, including healthy people and those already on blood pressure medications.² In a controlled trial of hypertensive patients, daily beetroot juice reduced clinic blood pressure by about 8/2 mm Hg over four weeks, with improvements in blood vessel function of roughly 20%.³ The effect held steady over the study period with no sign of the body adapting and becoming less responsive, which is a problem that plagues pharmaceutical nitrate drugs.

Beetroot juice also has performance benefits for athletes and anyone who exercises. In a placebo-controlled study, drinking beetroot juice reduced the oxygen cost of walking and moderate running, and extended time to exhaustion during hard running by about 15%.⁴ That is a significant jump for something as simple as a glass of juice.

Beetroot is not the only option. Leafy greens like spinach, arugula, and lettuce tend to contain even more nitrate per serving than root vegetables.⁵ One practical note: cooking reduces nitrate content by roughly 4 to 13%, so eating some of your greens raw or lightly cooked preserves more of the beneficial compound.⁵

Try L-Citrulline Instead of L-Arginine

Many supplement labels advertise L-arginine as a nitric oxide booster, because arginine is the amino acid your body’s enzyme uses as raw material to produce NO.⁶ The logic sounds airtight: give the body more raw material, get more product. In practice, arginine supplements are not very efficient. About 70% of the arginine you swallow gets broken down before it ever reaches your general circulation.⁷

L-citrulline, an amino acid found naturally in watermelon, avoids that bottleneck. When you take citrulline, virtually all of it enters the bloodstream intact and then gets converted to arginine by the kidneys. In a head-to-head pharmacokinetic study in humans, citrulline raised plasma arginine levels more effectively than arginine itself at equivalent doses. At the highest dose tested, citrulline also increased markers of nitric oxide production, including urinary nitrate and the downstream signaling molecule cGMP.⁸ Animal data supports the same pattern: supplemental citrulline raised plasma arginine concentrations about 35% more than supplemental arginine did.⁷

If you are choosing between the two supplements, citrulline is the better bet for actually moving the needle on nitric oxide. Eating watermelon provides some citrulline naturally, though the amounts are small compared to a dedicated supplement.

Get Some Sunlight on Your Skin

Your skin is a surprisingly large reservoir of nitrogen-containing compounds that can release nitric oxide when exposed to ultraviolet A (UVA) light. In a study of healthy volunteers, whole-body UVA exposure caused blood pressure to drop significantly within 30 minutes, with systolic pressure falling by about 11%. The researchers also saw increased blood flow in the forearm and decreased vascular resistance, all tightly correlated with rising levels of nitric oxide-related compounds in the blood.⁹

A follow-up study with 24 volunteers confirmed that UVA irradiation lowers blood pressure and releases nitric oxide from preformed stores in the upper layers of the skin, independently of the enzyme system that normally makes NO inside blood vessels.¹⁰ This means sunlight activates a completely separate nitric oxide source from the one that responds to diet or exercise. The researchers suggested this mechanism could help explain why blood pressure and cardiovascular disease rates tend to be higher in winter months and at higher latitudes, where UVA exposure is lower.

You do not need to sunbathe for hours. The doses used in these studies were moderate, and the blood pressure effects appeared quickly and lasted up to an hour. Routine outdoor time with some skin exposed, particularly during midday when UVA levels are highest, appears to be enough to engage this pathway. The trade-off with skin cancer risk is real but is primarily driven by UVB, the burn-causing wavelength, rather than UVA. Reasonable sun exposure without burning is the practical takeaway.

Breathe Through Your Nose

This one catches people off guard: your paranasal sinuses continuously produce nitric oxide gas. When you breathe through your nose, you carry that NO directly into your lungs with each inhale. When you breathe through your mouth, you bypass this entirely.¹¹

The effects are measurable. In one study, healthy subjects had higher blood oxygen levels during nasal breathing compared to oral breathing, likely because the inhaled NO helped dilate small blood vessels in the lungs and improved oxygen exchange.¹² A separate study measured pulmonary vascular resistance and found it was lower during nasal breathing than during mouth breathing, consistent with the idea that sinus-derived NO relaxes the lung’s blood vessels in real time.¹³

Researchers have called sinus NO an “aerocrine” hormone, meaning a gas-phase signaling molecule that is produced in one place and transported to its site of action through the air you breathe.¹¹ It is an elegant system, and it costs you nothing to use it. Simply making a habit of nasal breathing during rest, sleep, and light exercise delivers a small but steady pulse of nitric oxide to your lungs throughout the day. Mouth breathing during intense exercise is normal and unavoidable, but defaulting to nasal breathing the rest of the time is a free win.

Stop Using Antiseptic Mouthwash Daily

This is the counterintuitive one. The same bacteria on your tongue that convert dietary nitrate into nitrite are wiped out by strong antiseptic mouthwashes, particularly chlorhexidine-based products. Kill those bacteria and you shut down a major pathway for nitric oxide production.

In a study of 19 healthy volunteers, seven days of chlorhexidine mouthwash reduced the mouth’s ability to convert nitrate to nitrite by 90% and dropped plasma nitrite levels by 25%. Blood pressure rose by 2 to 3.5 mm Hg, and the increase correlated directly with the fall in circulating nitrite.¹⁴ A separate study in people already being treated for high blood pressure found that just three days of antibacterial mouthwash raised systolic blood pressure by about 2.3 mm Hg, alongside clear drops in salivary nitrite.¹⁵

A review in a critical care journal went further, noting that because antiseptic mouthwashes eradicate the oral bacterial communities responsible for the nitrate-to-nitrite step, the entire dietary nitric oxide pathway can be abolished. The authors raised the possibility that this could contribute to complications in hospitalized patients, including heart events and sepsis.¹⁶

A couple of millimeters of mercury might sound trivial, but across a population it is not. And if you are someone who eats well, exercises, and takes beetroot juice specifically to boost nitric oxide, then gargling with chlorhexidine mouthwash each morning is actively undermining those efforts. Regular toothbrushing and flossing keep your teeth and gums healthy without scorching the bacteria your cardiovascular system relies on.

Eat Foods Rich in Antioxidants and Polyphenols

Nitric oxide is a fragile molecule. It gets destroyed almost instantly by reactive oxygen species, the byproducts of normal metabolism that accumulate faster when your diet is poor or inflammation is high. Even if your body produces plenty of NO, high oxidative stress can break it down before it has a chance to act. Antioxidants help on both ends: they can protect nitric oxide from being scavenged by free radicals and may also support the enzyme that produces it in the first place.¹⁷

Cocoa is one of the better-studied examples. The flavanols in dark chocolate and cocoa products have been shown to improve endothelial function and lower blood pressure, with evidence pointing to reduced production of the free radicals that destroy NO.¹⁸ Other polyphenol-rich foods, including berries, red grapes, green tea, and pomegranate, follow similar logic. These foods do not supply nitric oxide directly. Instead, they create a chemical environment in your bloodstream where the NO you produce lasts longer and does more.

This also matters for the safety side of the dietary nitrate story. There is a common worry that nitrate from food could form nitrosamines, potentially carcinogenic compounds. But the antioxidants naturally present in vegetables, particularly vitamin C and polyphenols, block nitrosamine formation. An expert consensus panel noted that there is no evidence of harmful effects from dietary nitrate when consumed through vegetables, salads, or beetroot juice, precisely because these foods come packaged with protective antioxidants.¹⁹ The concern about nitrosamines applies mainly to processed meats, where nitrate and nitrite are added as preservatives without the accompanying antioxidant matrix.

Prioritize Sleep

Sleep deprivation appears to directly impair the enzyme system that generates nitric oxide in your blood vessel walls. In an animal model, disrupting REM sleep led to decreased activity of the enzyme that makes NO, lower levels of nitric oxide itself, and reduced levels of the downstream signaling molecule that tells smooth muscle to relax. The sleep-deprived animals also developed higher blood pressure.²⁰ While this is animal research and the findings have not been replicated in a controlled human sleep trial, the connection aligns with the well-established observation that poor sleep is a risk factor for high blood pressure and cardiovascular disease. If your blood vessels need rest to maintain their NO-producing machinery, chronically short sleep could be quietly draining your baseline nitric oxide levels.

Why Nitric Oxide Becomes Harder to Maintain With Age

One reason these strategies matter more as you get older is that the body’s enzymatic NO production declines with age. The enzyme in your blood vessel lining depends on a cofactor called tetrahydrobiopterin (BH4). In aged blood vessels, BH4 levels drop because the enzymes that make it become less active.²¹ When BH4 is scarce, the NO-producing enzyme misfires, generating damaging free radicals instead of beneficial nitric oxide. Aging also brings increased activity of oxidant enzymes and greater free radical production from other cellular sources, all of which destroy whatever NO is still being made.²²

This age-related decline is one reason the dietary nitrate pathway becomes so important for older adults. Even when the enzymatic route is compromised, the pathway that starts with nitrate-rich vegetables and tongue bacteria can still generate nitric oxide independently. Layering several of the strategies above, eating leafy greens, avoiding antiseptic mouthwash, getting some sunlight, and prioritizing antioxidant intake, creates multiple routes for NO production that do not all depend on the same aging enzyme.

How Dietary Nitrate Differs From Nitrate Medications

People sometimes worry that eating nitrate-rich foods is pharmacologically similar to taking nitroglycerin or other nitrate drugs used for chest pain. The two are quite different. Pharmaceutical nitrate drugs are organic nitrates, and with chronic use they produce tolerance, meaning the body stops responding, along with worsening endothelial function. Inorganic nitrate from food does not trigger tolerance and may actually compensate for declining endothelial function rather than making it worse.²³

The expert panel that reviewed dietary nitrate as a sports performance aid agreed on this distinction, adding that vegetable-derived nitrate supplements like beetroot juice contain antioxidants that naturally prevent any harmful byproducts from forming.¹⁹ While concerns about inorganic nitrate and cancer risk appear periodically in the press, direct evidence of harm in humans from food-sourced nitrate is lacking.²³ The safest strategy is the simplest: get your nitrate from actual vegetables and concentrated vegetable juices rather than from processed meat or isolated chemical supplements.

Red and Near-Infrared Light

An emerging area of research involves using red and near-infrared light to release nitric oxide from storage forms in tissue. Laboratory work has shown that these wavelengths can break apart nitric oxide from its bound forms in hemoglobin and myoglobin, freeing biologically active NO. In cardiac tissue studies, this released NO enhanced the protective effects of nitrite, suggesting a potential mechanism by which light therapy could locally increase NO availability.²⁴ This mechanism is distinct from the UVA-skin pathway described earlier, as it works on blood and muscle proteins rather than skin stores, and uses a different part of the light spectrum.

Red and near-infrared light devices are widely sold for home use, marketed for skin health, wound healing, and muscle recovery. The nitric oxide angle adds a possible cardiovascular dimension. However, most of the evidence so far comes from lab and tissue studies rather than large human trials, so it is too early to rank this alongside the well-proven strategies like dietary nitrate or nasal breathing. It is an area worth watching, especially for people already interested in photobiomodulation for other reasons.