What's the best supplement for nitrous oxide?

December 18, 2025 •

5 min read

While often confused with nitrous oxide, nitric oxide is a vital signaling molecule naturally produced in the body. A 2022 review of supplements that boost nitric oxide highlighted L-arginine, L-citrulline, and beetroot juice as effective dietary aids for enhancing synthesis, particularly in moderately trained individuals.

Quick Summary

This guide examines the most effective supplements for boosting nitric oxide, a key molecule for blood vessel dilation and circulation. It details the benefits and mechanisms of L-citrulline, L-arginine, and beetroot extract, helping you make an informed choice for performance and health.

Key Points

L-Citrulline is superior to L-Arginine: Due to its high bioavailability and effective conversion to L-arginine in the kidneys, L-citrulline offers a more sustained and reliable increase in nitric oxide.
Beetroot is a potent natural source: Beetroot extract and juice are rich in dietary nitrates, which the body converts to nitric oxide via an alternative pathway, especially beneficial for endurance.
Combinations can be synergistic: Some supplement formulas combine L-citrulline and L-arginine to capitalize on complementary pathways for maximum effect.
Focus on nitric oxide, not nitrous oxide: The article focuses on nitric oxide (NO) for circulation, not nitrous oxide ($N_2O$), or laughing gas, which is a common point of confusion.
Dosage and safety matter: Always follow recommended dosages, as high levels of L-arginine can cause digestive issues, and consult a healthcare professional before use, especially if on blood pressure medication.
Dietary intake is foundational: A diet rich in nitrate-heavy foods like leafy greens and beets, along with adequate antioxidants, supports natural nitric oxide production effectively.

Nitrous Oxide vs. Nitric Oxide: Clarifying a Common Misconception

Before exploring supplementation, it's crucial to clarify the difference between nitric oxide (NO) and nitrous oxide ($N_2O$). Nitric oxide is a natural signaling molecule that plays a crucial role in vasodilation, while nitrous oxide is commonly known as laughing gas. When people search for a supplement to boost “nitrous oxide,” they almost always mean nitric oxide, which is the focus of this article.

The Role of Nitric Oxide in the Body

As a potent vasodilator, nitric oxide signals the smooth muscles surrounding blood vessels to relax, causing them to widen and increase blood flow. This improved circulation helps deliver more oxygen and nutrients to working muscles and organs. This mechanism is particularly beneficial for athletes seeking enhanced performance and endurance, as well as for promoting cardiovascular health and managing blood pressure.

Key Supplements for Boosting Nitric Oxide

L-Citrulline

L-citrulline is an amino acid that has emerged as a superior choice for raising nitric oxide levels compared to its counterpart, L-arginine. Unlike L-arginine, a significant portion of which is broken down in the liver before it can reach the bloodstream, L-citrulline bypasses this metabolism. It is converted into L-arginine in the kidneys, leading to a more sustained and effective increase in plasma L-arginine and, consequently, nitric oxide production. Research suggests that L-citrulline can improve exercise performance, reduce muscle soreness, and lower blood pressure. Many pre-workout formulas now feature L-citrulline, often in combination with malate to form citrulline malate, which is also associated with increased energy production. A typical effective dosage is 6–8 grams taken approximately one hour before exercise.

L-Arginine

As the direct precursor to nitric oxide, L-arginine has long been used in supplements for boosting NO levels. However, its effectiveness is often hindered by poor bioavailability due to extensive breakdown in the digestive system. Despite this, L-arginine can still be beneficial, particularly for specific medical conditions and when taken in combination with other supplements. For healthy individuals focused purely on enhancing athletic performance, L-citrulline is generally considered the more efficient option. Typical daily dosages of L-arginine for NO support range from 2–6 grams. It can cause digestive issues at higher doses.

Beetroot Extract (Nitrates)

Dietary nitrates, found abundantly in beetroot and leafy greens like arugula and spinach, offer an alternative pathway for increasing nitric oxide. When consumed, nitrates are converted to nitrites by oral bacteria and then to nitric oxide in the body. Studies show that beetroot juice or extract can significantly increase plasma nitrite levels, leading to lower blood pressure and improved exercise performance, especially in endurance activities. Athletes often consume concentrated beetroot juice or powder before a workout to experience enhanced endurance and efficiency. The effect of nitrate supplementation can be quite rapid, with measurable cardiovascular effects occurring within hours of a single dose.

Combination Supplements

Many modern nitric oxide boosters combine multiple ingredients to maximize effectiveness through synergistic pathways. For example, combining L-citrulline and L-arginine can lead to higher and more sustained levels of plasma L-arginine than either supplement alone. Some formulas also add antioxidants, such as Vitamin C, which can help stabilize the volatile nitric oxide molecule, or other compounds like grapeseed extract and pine bark extract that support endothelial function. This multi-ingredient approach can offer more comprehensive support for blood flow and overall cardiovascular health.

Natural Food Sources of Nitric Oxide Precursors

While supplements offer a concentrated dose, you can also support your body’s natural nitric oxide production through diet. Nitrate-rich foods include beets, leafy greens, celery, and carrots. Watermelon is a natural source of L-citrulline, while protein-rich foods like meat, poultry, fish, and nuts contain L-arginine. Foods rich in antioxidants, like citrus fruits, also help maintain nitric oxide levels.

Conclusion

While L-arginine and beetroot extract are both viable options for boosting nitric oxide, L-citrulline often proves to be the most effective supplement for the general population due to its superior bioavailability and ability to sustain higher plasma L-arginine levels. For a more immediate effect or for those who prefer whole-food sources, nitrate-rich beetroot is an excellent choice. The combination of L-citrulline with L-arginine can also offer synergistic benefits for comprehensive blood flow support. As with any supplement, consulting a healthcare professional is recommended before starting a new regimen, especially if you have pre-existing health conditions or take other medications.

Comparison of Key Nitric Oxide Supplements


Feature	L-Citrulline	L-Arginine	Beetroot Extract	Combination Formulas
Mechanism	Converted to L-arginine in kidneys, then to NO. Bypasses liver metabolism.	Direct precursor to NO, but much is broken down in the liver.	Body converts dietary nitrates to nitrites, then to NO.	Combines L-Citrulline/L-Arginine with other compounds like antioxidants.
Bioavailability	High; avoids first-pass metabolism in the liver.	Low; significantly metabolized before reaching bloodstream.	High; absorbed efficiently, though conversion requires specific oral bacteria.	Can be high, depending on ingredient synergy and dosages.
Speed of Effect	Takes effect over time as it's converted to L-arginine.	Can provide a quick but shorter-lived boost in some cases.	Fairly rapid, with peak nitrate levels reached within 1–3 hours.	Varies, with some ingredients offering immediate effects and others a sustained release.
Primary Benefit	Sustained boost for endurance, muscle pumps, and recovery.	Targeted support for specific conditions under medical guidance.	Improved endurance and reduced oxygen cost, especially during exercise.	Comprehensive support for circulation, performance, and overall health.
Side Effects	Generally well-tolerated, even at higher doses.	Can cause gastrointestinal discomfort at higher doses.	Can cause dark red urine or stool (beeturia), which is harmless.	Depends on the specific ingredients and dosages in the formula.

Natural ways to boost nitric oxide production

Eat more nitrates: Consuming leafy greens and beets provides the body with the nitrates needed for the alternative NO production pathway.
Get enough antioxidants: These help preserve the short-lived nitric oxide molecule once it is produced.
Exercise regularly: Physical activity stimulates the endothelium to produce more nitric oxide, improving overall vascular health.
Limit antibacterial mouthwash: Some mouthwashes kill the beneficial bacteria in the mouth that are necessary for converting nitrates into nitrites.

Outbound Link

For a detailed scientific review on nitric-oxide synthesis, consider reading this study from the National Institutes of Health: Dietary supplements for improving nitric-oxide synthesis

Frequently Asked Questions

Nitric oxide (NO) is a natural molecule in the body that helps relax blood vessels, while nitrous oxide ($N_2O$) is known as laughing gas, used in medical procedures and recreational contexts. The topic of supplementation for circulation almost always refers to boosting nitric oxide.

L-citrulline has a higher bioavailability than L-arginine. A large portion of ingested L-arginine is metabolized by the liver before it can enter the bloodstream, whereas L-citrulline bypasses this process and is converted into L-arginine in the kidneys, leading to more sustained and higher NO levels.

The nitrates in beetroot are converted to nitrites by bacteria in the mouth. These nitrites are then converted to nitric oxide in the body, primarily in the stomach. This is an alternative pathway to the one involving L-arginine.

Yes, a balanced diet rich in nitrate-containing vegetables like beets and leafy greens, as well as foods with L-citrulline and L-arginine, can help support nitric oxide production. Supplements, however, offer concentrated doses for a stronger effect, particularly for athletes.

Most supplements are well-tolerated. High doses of L-arginine can cause digestive issues like bloating or diarrhea. Beetroot-based supplements can cause harmless beeturia (dark red urine). Consulting a doctor is advised, especially if you take other medications.

For exercise performance, it is generally recommended to take L-citrulline or beetroot extract about 60–90 minutes before a workout. For cardiovascular benefits, doses may be split throughout the day.

Nitric oxide supplements are not stimulants and do not cause jitters. Any jitters from a pre-workout formula typically come from added ingredients like caffeine, not the NO-boosting compounds themselves.