Table of ContentsView AllTable of ContentsUses of Nitric OxideNitric Oxide DeficiencySide EffectsPrecautionsDosageToxicityInteractionsSimilar SupplementsNutritionFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Uses of Nitric Oxide
Nitric Oxide Deficiency
Side Effects
Precautions
Dosage
Toxicity
Interactions
Similar Supplements
Nutrition
Frequently Asked Questions
Nitric oxide (NO) supplements are used to improve heart health, decrease high blood pressure in pregnancy, treat erectile dysfunction, and improve athletic performance.
NO is a naturally occurring gas that can relax your blood vessels to increase blood flow in your body.NO supplements, on the other hand, don’t have actual NO gas. Instead, the supplements typically contain substances that the body may use and convert to NO. These substances are amino acids—likeL-arginineandL-citrulline—andnitrates(NO3), which are the building blocks of proteins.
In the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it regulates prescription drugs. That means some supplement products may not contain what the label says. Whenchoosing a supplement, look for independently tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.
While more extensive research is necessary in regard to effectiveness, people use nitric oxide (NO) supplements for various health conditions.
Research is most robust for NO’s effects concerning the following:
Supplement Facts
Adding supplements to a pill organizer.Miniseries / Getty Images
Miniseries / Getty Images
Heart Health
NO supplements may contain substances—like the L-arginine amino acid.And your body may use and turn L-arginine into NO, which widens blood vessels and improves blood flow.
Due to these effects, NO supplements may support heart health.In fact, a systematic review and meta-analysis (analysis of a collection of studies) showed that L-arginine increased NO levels and blood flow in select groups of people, such as people withheart disease. These effects may also apply to people withexcess weight,type 2 diabetes, or both.
These results may support L-arginine’s effects on improving blood vessel function in people with heart disease risk. But it’s unclear how effective NO supplements—like L-arginine—are because of variability (important differences) between the studies. For example, there were differences in dosage forms, dosages (amounts or strengths), and how long L-arginine worked.
Additional research with higher-quality clinical trials is warranted—especially due to a concern that L-arginine might cause more harm in people with a recentheart attack.
High Blood Pressure in Pregnancy
High blood pressure in pregnancy is a dangerous condition that may negatively affect the parent and unborn fetus.
In an older study, pregnant people had lower blood pressure with long-term use of NO supplements, such as L-arginine.However, conflicting evidence exists for this use.
More research with higher-quality clinical trials is necessary to provide additional data.
Erectile Dysfunction
A review suggested that L-arginine alone or in combination with other medications might help people with erectile dysfunction (ED). The review article also mentioned a study supporting the use of L-citrulline—another NO supplement—in people with mild ED.
But future research with higher-quality and larger studies is still necessary.
Athletic Performance
A review article looked at short-term use of NO supplements—particularly L-citrulline and nitrates. It showed some promise in relaxing blood vessels and improving blood flow to increase muscle performance, size, and strength.
As for L-arginine, there is little evidence to support its use in improving athletic performance.
The evidence for these NO supplements is mixed. However, L-citrulline and nitrates seemed to be the most promising because they are better absorbed into the bloodstream when compared to L-arginine.
But additional research is still warranted, especially longer-term studies.
In recent years, there has been a lot of progress toward understanding nitric oxide (NO) and its effects in the human body.
Although additional extensive clinical trials are still necessary, research within the past few decades have shown a possible relationship between NO deficiency and several medical conditions.
What Causes a Nitric Oxide Deficiency?
In general, NO levels might depend on the following:
How Do I Know if I Have a Nitric Oxide Deficiency?
If you have a nitric oxide (NO) deficiency, you’ll experience such short-term symptoms as blood vessel dysfunction andhigh blood pressure.
In general, a low NO level is likely an early sign that hints at an onset of a chronic (long-term) medical condition.
Long-term or worsening NO deficiency symptoms may include the following:
What Are the Side Effects of Nitric Oxide?
Nitric oxide (NO) supplements, as with many medications and natural products, may have side effects.
Common Side Effects
Common side effects of NO supplements may include:
Severe Side Effects
Severe side effects are possible, especially with large doses of magnesium. Examples of serious side effects include:
If you’re having a severe allergic reaction or if any of your symptoms feel life-threatening, call 911 and get medical help right away.
Dietary supplements are not regulated like drugs in the United States. They can cause interactions with medications or have other safety concerns.For this reason, it’s important to be aware of what to look for whenchoosing a supplement, such as independent testing, potential drug interactions, and more.
Dietary supplements are not regulated like drugs in the United States. They can cause interactions with medications or have other safety concerns.
For this reason, it’s important to be aware of what to look for whenchoosing a supplement, such as independent testing, potential drug interactions, and more.
A healthcare provider may advise against using nitric oxide (NO) supplements if any of the following applies to you:
Dosage: How Much Nitric Oxide Should I Take?
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.
Each NO supplement may contain different ingredients in different amounts.
Moreover, further, extensive research with higher-quality clinical trials is warranted to better understand the effects and safety of NO supplements.
For these reasons, there are no guidelines on the appropriate dosage to take NO supplements for any condition.
If you take NO supplements, follow a healthcare provider’s suggestions and product label instructions.
What Happens if I Take Too Much Nitric Oxide?
In general, L-arginine and L-citrulline are considered safe.
However, each nitric oxide (NO) supplement might contain different ingredients in various amounts.
So, it’s impossible to know the overall safety of all NO supplements.
For this reason, more information about the safety, toxicity, and overdoses of individual NO supplements in humans is needed.
Symptoms of overdoses with NO supplements, however, are likely similar to its potential common and serious side effects—just excessive and more severe.
For example, high NO levels might result in lung injury andmethemoglobinemia, which can be life-threatening.
Inmethemoglobinemia, yourred blood cells(RBCs) are having trouble transporting oxygen throughout your body.Symptoms may include:
Nitric oxide (NO) supplements might interact with the following:
It is essential to carefully read a supplement’s ingredients list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.
In general, nitric oxide (NO) supplements—like L-arginine, L-citrulline, and nitrates—have potential uses for:
Other potentially similar supplements include the following:
Only combine multiple natural products after first talking with a healthcare provider, pharmacist, or dietitian. Checking in can help you avoid possible harmful interactions and side effects and ensure you’re giving these supplements a fair trial at appropriate doses.
There are several food sources of nitric oxide. Nutrition guidelines typically emphasize food sources of nutrients to improve health.
Food sources of nutrients are preferable to supplements.
However, there is still a place for supplements for certain groups of people, such as those with certain medical conditions.
What Foods Contain Nitric Oxide?
Some foods are rich in nitrates and nitrites.And through your diet, your body may convert the nitrates and nitrites to nitric oxide.
Examples of foods that are good sources of nitrates or nitrites are:
In general, fresh and leafy green vegetables are good options.
Amino acids may also be found in food. For example, foods that contain L-arginine include:
Nitric Oxide Supplements
Nitric oxide (NO) supplements don’t actually have the nitric oxide gas.
Instead, NO supplements typically contain substances, such as amino acids—like L-arginine and L-citrulline—and nitrates. And your body may convert these substances into nitric oxide.
In general, NO supplements are likely commonly available as capsules.Other dosage forms of NO supplements include:
But some of these other dosage forms might be in combination with other ingredients.
You may also see vegetarian and vegan options.
What is best for you will depend on form preference and what you hope to get in terms of effects.
Each product may work a bit differently, depending on the form.
Other Ways to Increase Nitric Oxide
Aside from diet or supplements, exercise is another way to increase nitric oxide (NO) levels.
Summary
Nitric oxide (NO) supplements contain substances that your body may turn into NO, which is a naturally occurring gas that relaxes blood vessels and increases blood flow.
NO supplements have a few potential uses for:
Since more extensive research is needed, you must ensure the diagnosis and treatment of your medical conditions are completed on time.
Before using NO supplements, ask a registered dietitian, pharmacist, or healthcare provider to weigh in on the process of deciding what may benefit you.
Frequently Asked QuestionsNitric oxide is a naturally occurring gas in your body.In your body, nitric oxide can relax your blood vessels to increase blood flow.Nitrite turns into nitric oxide in the body.In general, you may increase nitric oxide with diet, supplements, or exercise.To safely take supplements—like nitric oxide (NO) supplements—inform your healthcare providers and pharmacists about any and all medications you take.This includes over-the-counter (OTC), herbal, natural medicines, and supplements.They can help prevent possible interactions and side effects. They can also ensure that you’re giving NO supplements a fair trial at appropriate doses.
Nitric oxide is a naturally occurring gas in your body.
In your body, nitric oxide can relax your blood vessels to increase blood flow.
Nitrite turns into nitric oxide in the body.
In general, you may increase nitric oxide with diet, supplements, or exercise.
To safely take supplements—like nitric oxide (NO) supplements—inform your healthcare providers and pharmacists about any and all medications you take.This includes over-the-counter (OTC), herbal, natural medicines, and supplements.They can help prevent possible interactions and side effects. They can also ensure that you’re giving NO supplements a fair trial at appropriate doses.
26 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.The Department of Defense Dietary Supplement Resource: Operation Supplement Safety.Nitric oxide supplements.Food and Drug Administration.Drugs@FDA: FDA-approved drugs.United States Department of Agriculture.FoodData Central: Nitric oxide.Kiani AK, Bonetti G, Medori MC, et al.Dietary supplements for improving nitric-oxide synthesis.J Prev Med Hyg. 2022;63(2 Suppl 3):E239-E245. doi:10.15167/2421-4248/jpmh2022.63.2S3.2766LactMed.Nitric oxide.National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: nitric oxide.Rodrigues-Krause J, Krause M, Rocha IMGd, et al.Association of L-arginine supplementation with markers of endothelial function in patients with cardiovascular or metabolic disorders: a systematic review and meta-analysis.Nutrients. 2019;11(1):15. doi:10.3390%2Fnu11010015MedlinePlus.L-arginine.Rytlewski K, Olszanecki R, Korbut R, et al.Effects of prolonged oral supplementation with l-arginine on blood pressure and nitric oxide synthesis in preeclampsia.Eur J Clin Invest. 2005;35(1):32-7. doi:10.1111/j.1365-2362.2005.01445.xMagee L, von Dadelszen P.Prevention and treatment of postpartum hypertension.Cochrane Database Syst Rev. 2013;4:CD004351. doi:10.1002/14651858.CD004351.pub3Koolwal A, Manohar J. S, Rao TSS, et al.L-arginine and erectile dysfunction.Journal of Psychosexual Health. 2019;1(1):37-43: doi:10.1177/2631831818822018Gonzalez AM, Townsend JR, Pinzone AG, et al.Supplementation with nitric oxide precursors for strength performance: a review of the current literature.Nutrients. 2023;15(3):660. doi:10.3390/nu15030660Tonelli AR, Haserodt S, Aytekin M, et al.Nitric oxide deficiency in pulmonary hypertension: pathobiology and implications for therapy.Pulm Circ. 2013;3(1):20-30. doi:10.4103/2045-8932.109911Bryan NS.Nitric oxide deficiency is a primary driver of hypertension.Biochem Pharmacol. 2022;206:115325. doi:10.1016/j.bcp.2022.115325Almannai M, El-Hattab AW.Nitric oxide deficiency in mitochondrial disorders: The utility of arginine and citrulline.Front Mol Neurosci. 2021;14:682780. doi:10.3389/fnmol.2021.682780Bryan NS.Pharmacological therapies, lifestyle choices and nitric oxide deficiency: a perfect storm.Pharmacol Res. 2012;66(6):448-456. doi:10.1016/j.phrs.2012.09.009Food and Drug Administration.Inomax label.McNeal CJ, Meininger CJ, Reddy D, et al.Safety and effectiveness of arginine in adults.J Nutr. 2016;146(12):2587S-2593S. doi:10.3945/jn.116.234740Grimble GK.Adverse gastrointestinal effects of arginine and related amino acids.J Nutr. 2007;137(6):1693S-1701S. doi:10.1093/jn/137.6.1693SNational Center for Complementary and Integrative Health.6 things to know about dietary supplements marketed for bodybuilding or performance enhancement.National Center for Complementary and Integrative Health.Cardiovascular disease.National Center for Complementary and Integrative Health.Hypertension (high blood pressure).National Center for Complementary and Integrative Health.Yohimbe.Lentjes MAH.The balance between food and dietary supplements in the general population.Proc Nutr Soc. 2019;78(1):97-109. doi:10.1017%2FS0029665118002525USDA.FoodData Central: arginine.National Library of Medicine: MedlinePlus.A guide to herbal remedies.
26 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.The Department of Defense Dietary Supplement Resource: Operation Supplement Safety.Nitric oxide supplements.Food and Drug Administration.Drugs@FDA: FDA-approved drugs.United States Department of Agriculture.FoodData Central: Nitric oxide.Kiani AK, Bonetti G, Medori MC, et al.Dietary supplements for improving nitric-oxide synthesis.J Prev Med Hyg. 2022;63(2 Suppl 3):E239-E245. doi:10.15167/2421-4248/jpmh2022.63.2S3.2766LactMed.Nitric oxide.National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: nitric oxide.Rodrigues-Krause J, Krause M, Rocha IMGd, et al.Association of L-arginine supplementation with markers of endothelial function in patients with cardiovascular or metabolic disorders: a systematic review and meta-analysis.Nutrients. 2019;11(1):15. doi:10.3390%2Fnu11010015MedlinePlus.L-arginine.Rytlewski K, Olszanecki R, Korbut R, et al.Effects of prolonged oral supplementation with l-arginine on blood pressure and nitric oxide synthesis in preeclampsia.Eur J Clin Invest. 2005;35(1):32-7. doi:10.1111/j.1365-2362.2005.01445.xMagee L, von Dadelszen P.Prevention and treatment of postpartum hypertension.Cochrane Database Syst Rev. 2013;4:CD004351. doi:10.1002/14651858.CD004351.pub3Koolwal A, Manohar J. S, Rao TSS, et al.L-arginine and erectile dysfunction.Journal of Psychosexual Health. 2019;1(1):37-43: doi:10.1177/2631831818822018Gonzalez AM, Townsend JR, Pinzone AG, et al.Supplementation with nitric oxide precursors for strength performance: a review of the current literature.Nutrients. 2023;15(3):660. doi:10.3390/nu15030660Tonelli AR, Haserodt S, Aytekin M, et al.Nitric oxide deficiency in pulmonary hypertension: pathobiology and implications for therapy.Pulm Circ. 2013;3(1):20-30. doi:10.4103/2045-8932.109911Bryan NS.Nitric oxide deficiency is a primary driver of hypertension.Biochem Pharmacol. 2022;206:115325. doi:10.1016/j.bcp.2022.115325Almannai M, El-Hattab AW.Nitric oxide deficiency in mitochondrial disorders: The utility of arginine and citrulline.Front Mol Neurosci. 2021;14:682780. doi:10.3389/fnmol.2021.682780Bryan NS.Pharmacological therapies, lifestyle choices and nitric oxide deficiency: a perfect storm.Pharmacol Res. 2012;66(6):448-456. doi:10.1016/j.phrs.2012.09.009Food and Drug Administration.Inomax label.McNeal CJ, Meininger CJ, Reddy D, et al.Safety and effectiveness of arginine in adults.J Nutr. 2016;146(12):2587S-2593S. doi:10.3945/jn.116.234740Grimble GK.Adverse gastrointestinal effects of arginine and related amino acids.J Nutr. 2007;137(6):1693S-1701S. doi:10.1093/jn/137.6.1693SNational Center for Complementary and Integrative Health.6 things to know about dietary supplements marketed for bodybuilding or performance enhancement.National Center for Complementary and Integrative Health.Cardiovascular disease.National Center for Complementary and Integrative Health.Hypertension (high blood pressure).National Center for Complementary and Integrative Health.Yohimbe.Lentjes MAH.The balance between food and dietary supplements in the general population.Proc Nutr Soc. 2019;78(1):97-109. doi:10.1017%2FS0029665118002525USDA.FoodData Central: arginine.National Library of Medicine: MedlinePlus.A guide to herbal remedies.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
The Department of Defense Dietary Supplement Resource: Operation Supplement Safety.Nitric oxide supplements.Food and Drug Administration.Drugs@FDA: FDA-approved drugs.United States Department of Agriculture.FoodData Central: Nitric oxide.Kiani AK, Bonetti G, Medori MC, et al.Dietary supplements for improving nitric-oxide synthesis.J Prev Med Hyg. 2022;63(2 Suppl 3):E239-E245. doi:10.15167/2421-4248/jpmh2022.63.2S3.2766LactMed.Nitric oxide.National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: nitric oxide.Rodrigues-Krause J, Krause M, Rocha IMGd, et al.Association of L-arginine supplementation with markers of endothelial function in patients with cardiovascular or metabolic disorders: a systematic review and meta-analysis.Nutrients. 2019;11(1):15. doi:10.3390%2Fnu11010015MedlinePlus.L-arginine.Rytlewski K, Olszanecki R, Korbut R, et al.Effects of prolonged oral supplementation with l-arginine on blood pressure and nitric oxide synthesis in preeclampsia.Eur J Clin Invest. 2005;35(1):32-7. doi:10.1111/j.1365-2362.2005.01445.xMagee L, von Dadelszen P.Prevention and treatment of postpartum hypertension.Cochrane Database Syst Rev. 2013;4:CD004351. doi:10.1002/14651858.CD004351.pub3Koolwal A, Manohar J. S, Rao TSS, et al.L-arginine and erectile dysfunction.Journal of Psychosexual Health. 2019;1(1):37-43: doi:10.1177/2631831818822018Gonzalez AM, Townsend JR, Pinzone AG, et al.Supplementation with nitric oxide precursors for strength performance: a review of the current literature.Nutrients. 2023;15(3):660. doi:10.3390/nu15030660Tonelli AR, Haserodt S, Aytekin M, et al.Nitric oxide deficiency in pulmonary hypertension: pathobiology and implications for therapy.Pulm Circ. 2013;3(1):20-30. doi:10.4103/2045-8932.109911Bryan NS.Nitric oxide deficiency is a primary driver of hypertension.Biochem Pharmacol. 2022;206:115325. doi:10.1016/j.bcp.2022.115325Almannai M, El-Hattab AW.Nitric oxide deficiency in mitochondrial disorders: The utility of arginine and citrulline.Front Mol Neurosci. 2021;14:682780. doi:10.3389/fnmol.2021.682780Bryan NS.Pharmacological therapies, lifestyle choices and nitric oxide deficiency: a perfect storm.Pharmacol Res. 2012;66(6):448-456. doi:10.1016/j.phrs.2012.09.009Food and Drug Administration.Inomax label.McNeal CJ, Meininger CJ, Reddy D, et al.Safety and effectiveness of arginine in adults.J Nutr. 2016;146(12):2587S-2593S. doi:10.3945/jn.116.234740Grimble GK.Adverse gastrointestinal effects of arginine and related amino acids.J Nutr. 2007;137(6):1693S-1701S. doi:10.1093/jn/137.6.1693SNational Center for Complementary and Integrative Health.6 things to know about dietary supplements marketed for bodybuilding or performance enhancement.National Center for Complementary and Integrative Health.Cardiovascular disease.National Center for Complementary and Integrative Health.Hypertension (high blood pressure).National Center for Complementary and Integrative Health.Yohimbe.Lentjes MAH.The balance between food and dietary supplements in the general population.Proc Nutr Soc. 2019;78(1):97-109. doi:10.1017%2FS0029665118002525USDA.FoodData Central: arginine.National Library of Medicine: MedlinePlus.A guide to herbal remedies.
The Department of Defense Dietary Supplement Resource: Operation Supplement Safety.Nitric oxide supplements.
Food and Drug Administration.Drugs@FDA: FDA-approved drugs.
United States Department of Agriculture.FoodData Central: Nitric oxide.
Kiani AK, Bonetti G, Medori MC, et al.Dietary supplements for improving nitric-oxide synthesis.J Prev Med Hyg. 2022;63(2 Suppl 3):E239-E245. doi:10.15167/2421-4248/jpmh2022.63.2S3.2766
LactMed.Nitric oxide.
National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: nitric oxide.
Rodrigues-Krause J, Krause M, Rocha IMGd, et al.Association of L-arginine supplementation with markers of endothelial function in patients with cardiovascular or metabolic disorders: a systematic review and meta-analysis.Nutrients. 2019;11(1):15. doi:10.3390%2Fnu11010015
MedlinePlus.L-arginine.
Rytlewski K, Olszanecki R, Korbut R, et al.Effects of prolonged oral supplementation with l-arginine on blood pressure and nitric oxide synthesis in preeclampsia.Eur J Clin Invest. 2005;35(1):32-7. doi:10.1111/j.1365-2362.2005.01445.x
Magee L, von Dadelszen P.Prevention and treatment of postpartum hypertension.Cochrane Database Syst Rev. 2013;4:CD004351. doi:10.1002/14651858.CD004351.pub3
Koolwal A, Manohar J. S, Rao TSS, et al.L-arginine and erectile dysfunction.Journal of Psychosexual Health. 2019;1(1):37-43: doi:10.1177/2631831818822018
Gonzalez AM, Townsend JR, Pinzone AG, et al.Supplementation with nitric oxide precursors for strength performance: a review of the current literature.Nutrients. 2023;15(3):660. doi:10.3390/nu15030660
Tonelli AR, Haserodt S, Aytekin M, et al.Nitric oxide deficiency in pulmonary hypertension: pathobiology and implications for therapy.Pulm Circ. 2013;3(1):20-30. doi:10.4103/2045-8932.109911
Bryan NS.Nitric oxide deficiency is a primary driver of hypertension.Biochem Pharmacol. 2022;206:115325. doi:10.1016/j.bcp.2022.115325
Almannai M, El-Hattab AW.Nitric oxide deficiency in mitochondrial disorders: The utility of arginine and citrulline.Front Mol Neurosci. 2021;14:682780. doi:10.3389/fnmol.2021.682780
Bryan NS.Pharmacological therapies, lifestyle choices and nitric oxide deficiency: a perfect storm.Pharmacol Res. 2012;66(6):448-456. doi:10.1016/j.phrs.2012.09.009
Food and Drug Administration.Inomax label.
McNeal CJ, Meininger CJ, Reddy D, et al.Safety and effectiveness of arginine in adults.J Nutr. 2016;146(12):2587S-2593S. doi:10.3945/jn.116.234740
Grimble GK.Adverse gastrointestinal effects of arginine and related amino acids.J Nutr. 2007;137(6):1693S-1701S. doi:10.1093/jn/137.6.1693S
National Center for Complementary and Integrative Health.6 things to know about dietary supplements marketed for bodybuilding or performance enhancement.
National Center for Complementary and Integrative Health.Cardiovascular disease.
National Center for Complementary and Integrative Health.Hypertension (high blood pressure).
National Center for Complementary and Integrative Health.Yohimbe.
Lentjes MAH.The balance between food and dietary supplements in the general population.Proc Nutr Soc. 2019;78(1):97-109. doi:10.1017%2FS0029665118002525
USDA.FoodData Central: arginine.
National Library of Medicine: MedlinePlus.A guide to herbal remedies.
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