Nitric oxide (NO) is a gas your body makes naturally to help blood vessels relax and improve blood flow. Despite its simple name, it plays an important role in heart health, exercise performance, and communication between cells.

Your body produces nitric oxide every day, but its availability can change with age and certain health conditions. The good news? Foods, exercise, and a few other healthy habits may help support its production.

Key Takeaways:

• Nitric oxide helps relax blood vessels, allowing blood to flow more easily.
• It supports healthy blood pressure, exercise function, and cellular communication.
• Beets, leafy greens, and regular exercise can support natural nitric oxide production.
• Nitric oxide supplements may offer benefits, but results depend on the ingredients and individual health.

What Is Nitric Oxide and What Does It Do?

Nitric oxide is a short-lived gas that acts as a signaling molecule. In simple terms, it helps cells communicate with one another.

One of its most important jobs is vasodilation, the process of relaxing and widening blood vessels.

When the inner lining of your blood vessels releases nitric oxide, it signals the surrounding smooth muscles to relax. This allows blood to flow with less resistance and helps regulate blood pressure. (1)

Nitric oxide also plays a role in:

• Brain function: Helps nerve cells communicate.
• Immune defense: Helps certain immune cells respond to pathogens.
• Muscle function: Supports the regulation of blood flow during physical activity.
• Sexual function: Helps relax blood vessels involved in erections.

Interestingly, nitric oxide is not something your body needs to store in large amounts. It breaks down within seconds, so your cells continually produce it when needed.

How Does Your Body Produce Nitric Oxide?

Your body has two main ways of making nitric oxide.

The L-arginine pathway

Cells use an amino acid called L-arginine to produce nitric oxide with the help of enzymes known as nitric oxide synthases (NOS).

This pathway is especially important in the endothelium, the thin layer of cells lining your blood vessels.

The nitrate-to-nitrite pathway

This process starts with dietary nitrates found in foods such as beets and leafy greens.

After you eat these foods, some nitrate enters your saliva, where certain bacteria on your tongue convert it into nitrite. Your body can then turn nitrite into nitric oxide.

Here's something surprising: your mouth bacteria help make this process work.

A 2025 clinical trial involving 75 younger and older adults examined how beetroot juice and antiseptic mouthwash affected oral bacteria and nitric oxide availability. The researchers found that nitrate-rich beetroot juice reduced mean arterial pressure by approximately 4 mmHg in older participants, but not in younger participants. (2)

This highlights how closely your oral microbiome and blood vessel health are connected.

What Are the Benefits of Nitric Oxide?

Nitric oxide performs several important functions, particularly in your cardiovascular system.

1. Supports Blood Flow and Healthy Blood Pressure

Nitric oxide helps blood vessels relax, reducing resistance as blood moves through them.

This is one reason researchers have investigated dietary nitrates for blood pressure management.

A 2025 meta-analysis of 75 randomized controlled trials involving 1,823 participants found that each additional millimole of dietary nitrate was associated with a 0.28 mmHg reduction in systolic blood pressure in acute studies. (3)

The review also reported improvements in certain measures of vascular function.

Although the results are encouraging, dietary nitrates should not replace prescribed blood pressure medication.

2. May Support Exercise Performance

During exercise, your muscles need more oxygen and nutrients.

Nitric oxide helps regulate blood vessel dilation, which can support blood delivery to working muscles.

A 2026 meta-analysis of 38 studies involving 703 participants found that beetroot juice supplementation produced a small improvement in VO₂max or VO₂peak, measures of the body's ability to use oxygen during exercise. (4)

The improvements were more noticeable in recreationally active adults. Researchers found less convincing benefits among highly trained athletes.

So, beetroot juice might help certain aspects of exercise performance, but it won't turn an occasional gym visitor into an Olympic athlete overnight.

3. Supports Brain Signaling and Immune Function

Nitric oxide also acts as a messenger in the nervous system, helping regulate communication between nerve cells.

Certain immune cells produce nitric oxide as part of the body's defense against pathogens. However, excessive nitric oxide production during inflammation can also contribute to tissue damage. (5)

The goal isn't to produce as much nitric oxide as possible. It's to maintain healthy nitric oxide signaling.

Does Nitric Oxide Production Decline With Age?

Nitric oxide availability can decrease as we age, particularly in blood vessels.

One reason is endothelial dysfunction, which occurs when the cells lining blood vessels become less effective at regulating circulation.

Age-related oxidative stress can also reduce nitric oxide availability by breaking it down before it performs its normal functions. (1)

This may contribute to increased blood vessel stiffness and changes in blood pressure.

However, there is no simple symptom checklist that can reliably identify low nitric oxide. Fatigue, cold hands, or poor exercise endurance can have many different causes.

How Can You Increase Nitric Oxide Naturally?

Supporting nitric oxide production doesn't have to involve expensive supplements. Several everyday habits can help.

1. Eat more nitrate-rich vegetables

Some of the best dietary nitrate sources include:

• Beets and beetroot juice
• Spinach
• Arugula
• Lettuce
• Celery

Your body can convert these dietary nitrates into nitric oxide. Research suggests this pathway may support healthy blood pressure and certain aspects of exercise performance. (3)

2. Exercise regularly

Physical activity increases blood flow and stimulates the endothelium, helping support nitric oxide signaling.

Walking, cycling, swimming, and resistance training can all contribute to cardiovascular health.

3. Consider nitric oxide precursor supplements

L-arginine and L-citrulline are two ingredients found in nitric oxide supplements.

L-arginine directly contributes to nitric oxide production, while L-citrulline helps the body produce more arginine.

However, the National Institutes of Health notes that research on their exercise performance benefits remains limited and inconsistent. (6)

4. Pay attention to oral health

Certain antiseptic mouthwashes can interfere with nitrate-converting bacteria in the mouth.

That doesn't mean you should stop using a dentist-recommended mouthwash. It simply shows that oral bacteria have a role beyond keeping your mouth healthy.

Are Nitric Oxide Supplements Safe?

Nitric oxide precursor supplements are generally tolerated at doses studied in clinical trials, but they aren't risk-free.

Depending on the ingredient and dose, side effects may include:

• Stomach discomfort, nausea, or diarrhea
• Headaches
• Reduced blood pressure
• Potential interactions with blood pressure medications

People taking nitrates, blood pressure medications, or erectile dysfunction medications should speak with their healthcare provider before trying nitric oxide supplements.

Also, remember that a product labeled a "nitric oxide booster" contains ingredients intended to influence nitric oxide production, not nitric oxide gas itself.

Final Words

Nitric oxide might be invisible, but its effects on circulation and cellular communication are anything but small. Eating nitrate-rich vegetables, staying active, and maintaining good cardiovascular health can help support the processes that keep it working.

Healthy aging also depends on how well your cells produce and use energy. If you're exploring ways to support cellular health, Omre NMN + Resveratrol combines two ingredients studied for their roles in NAD+ metabolism and healthy aging. It's not a direct nitric oxide booster, but it may fit into a broader approach to supporting cellular health.

FAQs

What is nitric oxide used for in the body?

Nitric oxide helps regulate blood flow, blood pressure, nerve signaling, immune responses, and sexual function. Its best-known role is relaxing blood vessels.

What foods are highest in nitric oxide precursors?

Beets, arugula, spinach, lettuce, and celery contain dietary nitrates that the body can convert into nitric oxide. The amount varies depending on growing conditions and preparation.

Does nitric oxide help lower blood pressure?

Nitric oxide helps blood vessels relax, which can reduce blood pressure. Clinical trials suggest dietary nitrate supplementation may produce modest improvements, although results vary between individuals.

What are the signs of low nitric oxide?

Reduced nitric oxide availability may contribute to impaired blood vessel function, but there are no reliable symptoms that specifically confirm low nitric oxide. Blood pressure changes, fatigue, or poor circulation require proper medical evaluation.

Is nitric oxide the same as nitrous oxide?

No. Nitric oxide (NO) is a signaling molecule naturally produced in the body. Nitrous oxide (N₂O), sometimes called laughing gas, is a different chemical used in medical and dental anesthesia.

References

(1) Nitric Oxide and Endothelial Dysfunction. Current Hypertension Reports, 2020.

(2) Ageing Modifies the Oral Microbiome, Nitric Oxide Bioavailability and Vascular Responses to Dietary Nitrate Supplementation. Free Radical Biology and Medicine, 2025.

(3) Plasma Nitrate, Dietary Nitrate, Blood Pressure, and Vascular Health Biomarkers: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials. Nutrition Journal, 2025.

(4) Effects of Beetroot Juice Supplementation on Maximal Oxygen Uptake During Aerobic Exercise: A Systematic Review and Meta-Analysis. Frontiers in Nutrition, 2026.

(5) Modulation of Autoimmune Diseases by Nitric Oxide. Immunologic Research, 2000.

(6) Dietary Supplements for Exercise and Athletic Performance. National Institutes of Health, Office of Dietary Supplements.