:max_bytes(150000):strip_icc()/GettyImages-1393158704-d2ad4e6133b743d58b68beed3da99469.jpg)
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—like L-arginine and L-citrulline—and nitrates (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. When choosing a supplement, look for third-party 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:
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 with heart disease. These effects may also apply to people with excess 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 recent heart attack.
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.
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.
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.
In general, NO levels might depend on the following:
If you have a nitric oxide (NO) deficiency, you'll experience such short-term symptoms as blood vessel dysfunction and high 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:
Nitric oxide (NO) supplements, as with many medications and natural products, may have side effects.
Common side effects of NO supplements may include:
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 when choosing a supplement, such as third-party 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:
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.
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 and methemoglobinemia, which can be life-threatening.
In methemoglobinemia, your red 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.
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 (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.
Following a healthcare provider's recommendations or label directions is essential.
Aside from diet or supplements, exercise is another way to increase nitric oxide (NO) levels.
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.
