What is the best nitrogen oxide supplement? An expert guide

December 22, 2025 •

4 min read

According to a 2022 review, consuming between 2.4g and 6g of L-citrulline daily can help the body produce more nitric oxide and improve exercise performance. With so many options available, figuring out what is the best nitrogen oxide supplement for your needs requires understanding the key ingredients and formulations.

Quick Summary

This guide breaks down the different types of nitrogen oxide boosting supplements, examining key ingredients like L-citrulline, L-arginine, and beetroot extract. It explains how they function in the body, highlights their benefits for exercise performance and cardiovascular health, and compares top product formulations to help with selection.

Key Points

L-Citrulline is Highly Effective: The amino acid L-citrulline is a superior precursor to nitric oxide than L-arginine, as it is better absorbed and converted in the kidneys.
Beetroot Boosts NO Naturally: High in dietary nitrates, beetroot extract provides an alternative pathway for increasing nitric oxide, which is especially beneficial during moderate-intensity exercise.
Pre-Workouts Offer Comprehensive Formulas: Products like Type Zero and Gorilla Mode combine nitric oxide boosters with other performance-enhancing ingredients for a more potent effect.
Capsules vs. Powder: Powders often provide faster absorption and more flexible dosing, while capsules offer convenient, measured doses.
Consider Third-Party Testing: To ensure safety and ingredient accuracy, look for supplements that have been independently verified by a third-party laboratory.
Not for Everyone: Individuals with certain health conditions, like heart or kidney issues, or those on specific medications should consult a doctor before use.

What are Nitrogen Oxide Supplements and How Do They Work?

Nitrogen oxide, more commonly known as nitric oxide (NO), is a vital signaling molecule naturally produced by the body that plays a key role in various physiological processes. Its most notable function is vasodilation, which means it relaxes the inner muscles of blood vessels, causing them to widen. This widening increases blood flow, which in turn delivers more oxygen and nutrients to the muscles and other organs.

Nitrogen oxide supplements do not contain nitric oxide directly, but rather provide the body with precursors or building blocks needed to increase its natural production. The two primary pathways for boosting NO are the L-arginine/L-citrulline pathway and the nitrate-nitrite pathway. By supporting these processes, supplements can offer a range of benefits, from enhanced athletic performance to improved cardiovascular health.

The Role of Key Ingredients

Several compounds are commonly used in supplements to increase nitric oxide levels. Understanding their function is key to finding the best product for you.

L-Citrulline: This amino acid is often considered more effective than L-arginine for boosting NO levels. When ingested, L-citrulline bypasses liver metabolism and is converted into L-arginine in the kidneys, which is then used to synthesize nitric oxide. Studies show it can increase exercise capacity and reduce muscle soreness.
L-Arginine: While a direct precursor to NO, L-arginine is heavily metabolized by the liver, meaning less of it reaches the bloodstream to be converted to nitric oxide. For this reason, L-citrulline is often the preferred and more bioavailable option, although some supplements use a combination of both.
Beetroot Extract: Rich in dietary nitrates, beetroot provides an alternative, NO-synthase-independent pathway for nitric oxide production. Nitrates are converted to nitrites by bacteria in the mouth and then further reduced to nitric oxide in the body. This pathway is particularly effective during exercise.
Nitrosigine: This is a patented complex of bonded arginine silicate that is designed to be more bioavailable and effective at raising NO levels than standard L-arginine.
Antioxidants: Compounds like vitamin C, flavonoids, and pomegranate extract are included in some formulas because they may protect nitric oxide from breaking down prematurely, thus prolonging its effects.

Top Nitrogen Oxide Supplements Compared

Choosing a supplement depends on your goals, preferences (powder vs. capsules), and budget. The table below compares some highly-regarded options based on common user priorities.


Feature	Type Zero Clean Stim-Free Pre-Workout	HumanN SuperBeets Sport	Nutricost Nitric Oxide Booster	Bulk Supplements L-Citrulline Malate	Gorilla Mode Nitric
Primary Ingredients	L-Citrulline, L-Arginine, Beetroot Extract	Beetroot Powder (Fermented)	L-Arginine, L-Citrulline Malate	L-Citrulline Malate 2:1	L-Citrulline, Creatine, Glycerol
Best For	Overall Performance (Pre-Workout)	Cardiovascular & Heart Health	Budget-Conscious Users	Customizable Dosing & Stacking	Maximum Performance & Pumps
Form	Powder	Powder	Capsules	Powder	Powder
Key Advantages	Comprehensive formula, great taste options, clean ingredients.	High-quality beetroot, third-party tested, simple ingredient list.	High value, simple formula, capsule convenience.	Cost-effective, bulk size, no fillers.	Intense, targeted performance formula.
Potential Downsides	Can be more expensive than single-ingredient options.	Strong beet flavor may not appeal to all users.	Capsule format may offer slower absorption.	Requires a separate scale for accurate dosing.	More complex formula with many ingredients.

How to Choose the Right Supplement

Selecting the best nitrogen oxide supplement for you involves a personal assessment of your goals and preferences.

For Athletes and Gym-Goers: A pre-workout formula like Type Zero or Gorilla Mode Nitric offers a combination of NO boosters and other ergogenic aids (like creatine) for enhanced performance, pumps, and endurance during training. L-Citrulline malate is a key component to look for here due to its effect on muscle soreness and performance.

For General Health and Circulation: For those focused on cardiovascular support and blood pressure, a high-quality beetroot-based product like HumanN SuperBeets Sport is an excellent choice. The nitrate pathway is well-researched for these benefits and can be a gentler option than high-dose amino acid complexes.

For Budget-Friendly Options and Simplicity: If you are new to nitric oxide supplementation or want to try single ingredients without a hefty price tag, Bulk Supplements offers pure L-arginine and L-citrulline powders. Nutricost provides a high-potency, straightforward capsule option combining L-arginine and L-citrulline.

Important Considerations and Safety

While generally considered safe for most healthy adults, nitrogen oxide supplements can cause mild side effects, particularly at high doses. These can include gastrointestinal discomfort, bloating, or mild headaches. It is also important to note that dietary supplements are not as strictly regulated as prescription medications.

Medical Supervision: Consult with a healthcare professional before starting any new supplement, especially if you have pre-existing health conditions like heart disease, kidney issues, or low blood pressure. Certain individuals, such as those who have recently had a heart attack, may face increased risks.
Medication Interactions: Nitric oxide supplements can interact with medications for blood pressure and diabetes, potentially causing unwanted side effects.
Quality Control: Look for supplements that are third-party tested and manufactured in GMP-certified facilities to ensure purity and potency.

Conclusion: Finding the Right Fit

There is no single "best" nitrogen oxide supplement for everyone, as the ideal choice depends on individual goals, ingredient tolerance, and budget. L-citrulline and beetroot extract are among the most scientifically supported ingredients for boosting NO levels effectively for exercise performance and cardiovascular health, respectively. For a comprehensive pre-workout, a multi-ingredient formula is best, while a single-ingredient bulk powder is ideal for those who prefer full control over their dosage or for cost savings. Always prioritize supplements that are third-party tested and consult a doctor before use to ensure safety and effectiveness. By evaluating your needs and weighing the pros and cons of different ingredients and product types, you can make an informed decision and find the best nitrogen oxide supplement for your regimen.

For more in-depth information on nitric oxide and its biological roles, consider reviewing authoritative sources like those found in the National Institutes of Health's PubMed Central, such as this article: Dietary supplements for improving nitric-oxide synthesis.

Frequently Asked Questions

The primary benefit of a nitrogen oxide (NO) supplement is its ability to increase blood flow by relaxing and widening blood vessels. This can lead to enhanced athletic performance, improved cardiovascular health, and better nutrient delivery to muscles.

L-citrulline is generally considered more effective for boosting nitric oxide levels than L-arginine. This is because L-citrulline is less prone to breakdown in the liver and more efficiently converted to arginine in the kidneys for NO synthesis.

Yes, natural ways to increase nitric oxide include eating foods rich in nitrates, such as beetroot and leafy green vegetables like spinach and arugula. Regular exercise is also known to increase the body's natural production of NO over time.

Some studies suggest that nitric oxide supplements, particularly those containing L-arginine and L-citrulline, may help with mild to moderate erectile dysfunction by improving blood flow. However, these supplements are not a primary treatment and should not replace advice from a healthcare professional.

Individuals with pre-existing conditions such as heart disease, kidney disease, low blood pressure, or liver cirrhosis should consult a doctor before use. People who have recently experienced a heart attack are also advised against taking L-arginine supplements.

While generally well-tolerated, some mild side effects can occur, including gastrointestinal issues like upset stomach, bloating, or diarrhea, particularly with high doses. Headaches and palpitations have also been reported.

Powdered supplements, like L-citrulline malate, can be mixed with water for faster absorption, offering flexibility in dosage. Capsules, such as Nutricost's, provide a convenient, pre-measured dose and are easier to take on the go.