Nitric oxide is a small, volatile compound important for health and well-being. It’s involved in nearly every body system, and nitric oxide supplements may offer benefits for athletic performance, muscle soreness, cardiovascular health, and more.
If you’re into fitness, you’ve probably heard about nitric oxide. It’s a tiny molecule produced by nearly every cell in the body and is one of the most important compounds for cardiovascular health. It’s a potent vasodilator that widens blood vessels to allow for better blood flow.
And as one of the most popular health and fitness supplements rolling off shelves, people are catching on.
If you’re new to the game and aren’t familiar with nitric oxide, we have your back! We’re giving you a breakdown of everything you want to know about nitric oxide, starting with the basics.
Here are the top 5 health and performance benefits of nitric oxide supplements.
Nitric oxide: What is it and what does it do?
Before diving into nitric oxide’s health benefits, what exactly is it? Nitric oxide, sometimes just shortened to NO, is an odorless and colorless gas and free radical composed of one molecule of nitrogen and one molecule of oxygen.
It’s produced in nearly every cell in the human body and is synthesized enzymatically from the amino acid L-arginine via nitric oxide synthase 1.
NO is an essential molecule in the endothelium-dependent regulation of blood flow and blood pressure and is recognized as a neurotransmitter in certain types of nerves 1.
That’s not a complete picture of what NO does in the body, but it has many molecular effects that give it a diverse range of physiological actions that support health and performance.
But why should we care about it?
Aside from its many roles in nearly every body system, nitric oxide is a key mediator of cell-to-cell communication and is essential for inflammation, vasodilation, and neurotransmission, among others.
5 Health and Performance Benefits of Taking nitric oxide supplements
1. May help erectile dysfunction (ED)
Erectile dysfunction is a common and multidimensional condition mainly affecting men over 40. It involves altering several components of the erectile response and can have organic, relational, and psychological components 2.
Because proper erectile function has been a symbol of a man’s virility and sexual prowess, ED is often a shameful and embarrassing condition.
However, while the roots of ED are complex, many natural supplements can enhance erectile function and treat ED. Citrulline and arginine are two of the most common amino acids used to treat ED by boosting nitric oxide production 3.
Nitric oxide activates the relaxation of smooth muscle tissue in the penis, resulting in increased blood flow and an erection 4.
Many of the pharmacological treatments available for ED potentiate the erectile response by generating NO.
Here’s what some research shows 5, 6:
- L-citrulline supplementation via acting as a donor for the L-arginine/nitric oxide pathway of penile erection safely and effectively erection hardness
Key takeaway: Nitric oxide is essential for male erectile function. Studies show that NO precursors like L-citrulline and L-arginine can increase NO levels and improve male sexual function.
2. Reduces blood pressure
Hypertension is the leading cause of cardiovascular disease and premature death, and it’s estimated that more than 31% of adults (1.39 billion) worldwide have or have had hypertension 7.
It is a condition that affects arteries whereby blood pressure pushing against the arteries is too high, leading to extra stress on the heart.
But what’s interesting is that endothelial dysfunction—impaired bioavailability of nitric oxide (NO)—is a significant risk factor for hypertension and cardiovascular disease 8.
Because of its vasodilation properties, NO plays a vital role in regulating blood pressure, and impaired NO bioactivity may be a key component of hypertension (high blood pressure).
But what does the research say?
Studies show that diets high in fruits and vegetables can positively impact blood pressure and reduce the risk of disease—and there are two primary compounds you can thank for this 9.
- Nitrate: Dietary nitrates are found in foods like beetroot and dark leafy green vegetables and is the precursor to nitric oxide, which, in turn, helps to dilate blood vessels and reduce blood pressure. Increasing your intake of nitrate-rich foods can help boost NO production and lower blood pressure 10, 11.
- Flavonoids: Much like nitrates, flavonoids have been shown to reduce blood pressure thanks to their potent antioxidant properties 12, 13. Researchers suggest flavonoids can boost NO production and decrease its breakdown, helping maintain higher levels.
Key takeaway: Thanks to nitric oxide’s powerful vasodilatory effects, increasing levels through food or supplementation can help dilate arteries and reduce high blood pressure inside vessels.
3. Enhance exercise performance
Struggling to hit that PR you’ve been chasing? Craving a better pump? It turns out that all you may need is a bit of nitric oxide supplementation.
Because of its inherent vasodilatory effects, NO can widen blood vessels to increase oxygen and nutrient delivery to active muscle tissue, thereby enhancing performance.
This is often why you’ll see compounds like arginine and citrulline in pre-workout formulas—they help to improve blood flow and stimulate the pump, thereby improving exercise performance.
And studies agree. Research has found that nitrate (the precursor to nitric oxide) can improve athletic performance in various athletes 14, 15. However, L-arginine supplementation didn’t show the same promise.
Why? It may be because when supplementing with L-arginine, most of it is metabolized or degraded before it reaches the bloodstream and can form nitric oxide, whereas L-citrulline is not 16.
Key takeaway: Taking nitric oxide supplements like L-citrulline may improve exercise performance. However, L-arginine hasn’t shown the same degree of success.
4. May reduce muscle soreness
If you’ve ever had a gruesome workout only to be sore beyond belief two days after, you know how desperate you can be for any sign of relief.
Citrulline malate, a form of L-citrulline, has not only been shown to increase the production of nitric oxide but also may help reduce muscle soreness.
A 2010 study published in the Journal of Strength and Conditioning Research looked at the effects of citrulline malate on bench press performance and muscle soreness after exercise 17.
Researchers found that 8 grams of citrulline malate one hour before exercise led to 40% less muscle soreness at 24- and 48 hours post-exercise.
Why such a big difference? Citrulline malate is known to increase NO production, which increases blood flow, but it may also improve nutrient delivery and metabolic waste clearance that can lead to muscle soreness such as lactate and ammonia 18.
However, the effectiveness of citrulline malate to alleviate muscle soreness is largely related to the dose, with higher doses yielding better effects.
Key takeaway: Citrulline malate may help to mitigate muscle soreness post-exercise by increasing NO production, which helps to enhance nutrient delivery and boost waste removal of compounds that can lead to soreness.
5. Supports brain health
While several compounds support cognitive function, NO is yet another that’s been shown to be particularly valuable in the brain.
It functions as an essential messenger molecule in the central nervous system, acting as an intermediary in cellular communication within the brain 19.
Research from the University of Leicester shows that NO can change the “computational ability” of the brain, suggesting that it may be beneficial for treating neurodegenerative diseases like Alzheimer’s 20.
Another study published in Functional Neurology shows that reduced NO production may explain the impaired ability of patients with neurodegenerative diseases to learn new information 19.
Key takeaway: Nitric oxide functions as an important chemical messenger in the brain and, based on current research, may offer a therapeutic approach to treating neurodegenerative disease.
How to increase nitric oxide naturally
It’s clear that nitric oxide is an important molecule, but if we can’t take it as a supplement, how do we get enough? The answer: food or supplementation.
Nitric oxide foods
How can you increase levels of nitric oxide naturally through your diet?
Although there aren’t foods that contain nitric oxide itself, there are foods that contain compounds known to boost NO production.
Most of these foods contain nitrates, which are then converted to nitrites and then produce nitric oxide in the body.
And the choices are simple: vegetables! A whopping 80% of dietary nitrates are found in vegetables, so load up—especially on beets and beet juice 21.
Some of the best nitrate-rich foods are 22:
- Red beets and beet greens
- Dark leafy greens, especially arugula (chard, spinach, lettuce)
Additionally, arginine is another precursor to nitric oxide production, so you can also boost your intake of high-protein arginine-rich foods to enhance NO levels 23. This includes eggs, grass-fed beef, wild-caught fish and seafood, pumpkin seeds, sunflower seeds, and spirulina.
Nitric oxide supplements
Some of the best nitric oxide boosting supplements contain red beetroot, like Pre Lab Pro®—the ultimate natural pre-workout designed to enhance all aspects of your performance.
Beets are a rich source of natural nitrates, and many studies support that beetroot can naturally increase NO levels, which may offer ergogenic effects on athletic performance 24, 25.
The other two options are L-arginine and L-citrulline supplements, the former of which isn’t as effective for boosting nitric oxide levels.
Key takeaway: Boosting NO levels through diet and supplements is easy, but most evidence suggests that beetroot provides the richest source of natural dietary nitrates and offers the most benefit for boosting NO levels.
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- Yafi FA, Jenkins L, Albersen M, et al. Erectile dysfunction. Nat Rev Dis Primers. 2016;2:16003.
- Barassi A, Corsi Romanelli MM, Pezzilli R, et al. Levels of l-arginine and l-citrulline in patients with erectile dysfunction of different etiology. 2017;5(2):256-261.
- Davies KP. Development and therapeutic applications of nitric oxide releasing materials to treat erectile dysfunction. Future Sci OA. 2015;1(1):FSO53.
- Cormio L, De Siati M, Lorusso F, et al. Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction. 2011;77(1):119-122.
- Stanislavov R, Nikolova V. Treatment of erectile dysfunction with pycnogenol and L-arginine. J Sex Marital Ther. 2003;29(3):207-213.
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- Hobbs DA, George TW, Lovegrove JA. The effects of dietary nitrate on blood pressure and endothelial function: a review of human intervention studies. Nutr Res Rev. 2013;26(2):210-222.
- Jonvik KL, Nyakayiru J, Pinckaers PJ, Senden JM, van Loon LJ, Verdijk LB. Nitrate-Rich Vegetables Increase Plasma Nitrate and Nitrite Concentrations and Lower Blood Pressure in Healthy Adults. J Nutr. 2016;146(5):986-993.
- Kapil V, Khambata RS, Robertson A, Caulfield MJ, Ahluwalia A. Dietary nitrate provides sustained blood pressure lowering in hypertensive patients: a randomized, phase 2, double-blind, placebo-controlled study. 2015;65(2):320-327.
- Loke WM, Hodgson JM, Proudfoot JM, McKinley AJ, Puddey IB, Croft KD. Pure dietary flavonoids quercetin and (-)-epicatechin augment nitric oxide products and reduce endothelin-1 acutely in healthy men. Am J Clin Nutr. 2008;88(4):1018-1025.
- Taubert D, Roesen R, Lehmann C, Jung N, Schömig E. Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide: a randomized controlled trial. JAMA. 2007;298(1):49-60.
- McMahon NF, Leveritt MD, Pavey TG. The Effect of Dietary Nitrate Supplementation on Endurance Exercise Performance in Healthy Adults: A Systematic Review and Meta-Analysis. Sports Med. 2017;47(4):735-756.
- Hoon MW, Johnson NA, Chapman PG, Burke LM. The effect of nitrate supplementation on exercise performance in healthy individuals: a systematic review and meta-analysis. Int J Sport Nutr Exerc Metab. 2013;23(5):522-532.
- Castillo L, Chapman TE, Yu YM, Ajami A, Burke JF, Young VR. Dietary arginine uptake by the splanchnic region in adult humans. Am J Physiol. 1993;265(4 Pt 1):E532-E539.
- Pérez-Guisado J, Jakeman PM. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. J Strength Cond Res. 2010;24(5):1215-1222.
- Takeda K, Machida M, Kohara A, Omi N, Takemasa T. Effects of citrulline supplementation on fatigue and exercise performance in mice. J Nutr Sci Vitaminol (Tokyo). 2011;57(3):246-250.
- Džoljić E, Grbatinić I, Kostić V. Why is nitric oxide important for our brain?. Funct Neurol. 2015;30(3):159-163.
- University of Leicester. “Nitric Oxide Can Alter Brain Function.” ScienceDaily. ScienceDaily, 27 November 2008. sciencedaily.com/releases/2008/11/081126133403.htm
- Hord NG, Tang Y, Bryan NS. Food sources of nitrates and nitrites: the physiologic context for potential health benefits. Am J Clin Nutr. 2009;90(1):1-10.
- Brkić D, Bošnir J, Bevardi M, et al. NITRATE IN LEAFY GREEN VEGETABLES AND ESTIMATED INTAKE. Afr J Tradit Complement Altern Med. 2017;14(3):31-41.
- Mirmiran P, Bahadoran Z, Ghasemi A, Azizi F. The Association of Dietary l-Arginine Intake and Serum Nitric Oxide Metabolites in Adults: A Population-Based Study. 2016;8(5):311.
- Domínguez R, Cuenca E, Maté-Muñoz JL, et al. Effects of Beetroot Juice Supplementation on Cardiorespiratory Endurance in Athletes. A Systematic Review. 2017;9(1):43.
- Baião Ddos S, Conte-Junior CA, Paschoalin VM, Alvares TS. Beetroot juice increase nitric oxide metabolites in both men and women regardless of body mass. Int J Food Sci Nutr. 2016;67(1):40-46.