Does Nitric Oxide Affect Testosterone? (Evidence-Based Research)

You might have noticed supplements being marketed to boost nitric oxide levels.

That’s because nitric oxide (NO) is said to improve exercise and sexual performance. Part of the reason for this improvement is that NO can help address low testosterone!

In this article, we’ll discuss what NO is and what it does to your body.

What Is Nitric Oxide and What Is the Role of Nitric Oxide in the Body?

Your body naturally produces nitric oxide, a gas compound.

It can lower the risk of cardiovascular disease by widening the blood vessels to improve blood flow. It also helps you manage your blood pressure.

Does Nitric Oxide Affect Testosterone? (Evidence-Based Research) 1

In effect, it can improve your athletic performance since the blood can reach muscles better. By doing so, NO can reduce recovery time.

NO helps your cells communicate with each other too. Because of that, it’s great for your immune system since it will allow the cells to react more quickly to any invaders.

It also stimulates the production of testosterone, growth hormone, and other hormones.

Interestingly, it can improve insulin effectiveness too. In turn, insulin boosts the growth hormone, which works with IGF-1 to produce more NO.

What Are the Benefits of Using Nitric Oxide Supplements?

These supplements can improve:

  • Cardiovascular health
  • Erectile dysfunction
  • Brain performance
  • Immunity
  • Sleep quality
  • Exercise stamina

NO supplements really don’t contain NO. Instead, they have ingredients that can help your body produce nitric oxide.

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The two main ingredients are the amino acids L-arginine and L-citrulline.

The kidneys actually convert L-citrulline into L-arginine, but having both gives the body more to work with for a longer time.

L-arginine is what’s directly involved in nitric oxide production.

The enzyme nitric oxide synthase (NOS) converts the amino acid into NO. The body can then use this for different processes.

How Does Nitric Oxide Affect Testosterone: Does Nitric Oxide Supplementation Increase Testosterone Levels?

NO is a vasodilator — it relaxes the small muscles in blood vessels.

It can treat erectile dysfunction since it allows for better blood flow to the penis.

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Aside from that, it also stimulates the release of gonadotropin. This is one of the primary hormones involved in the creation of testosterone.

NO supplements were created to increase nitric oxide levels so you can reap the benefits.

But here’s the thing: These are what NO supplements do in theory.

The reality is that more research needs to be done to ensure their effectiveness. A review of many studies shows mixed results (1).

This is because exercise already increases NO. Foods like vegetables also contribute to NO production by providing dietary nitrate.

Are There Any Side Effects of Nitric Oxide Supplementation?

NO supplements are generally safe.

But be aware that side effects can include:

  • Lower dopamine levels - NO releasers can hinder dopamine transporters. Dopamine regulates various processes in the body, and reduced dopamine levels can negatively affect them. These include:
    • Cognitive ability
    • Memory
    • Motivation levels
    • Sleep cycles
  • Zinc deficiency - Too much NO can cause a chain reaction that will result in zinc deficiency. If you lose too much zinc, you may experience the following:
    • Diarrhea
    • Lower sex drive
    • Loss of appetite
  • Gastrointestinal distress - Many of the amino acids (especially L-arginine) involved in the creation of NO are known to cause gastrointestinal distress. Some problems you may experience are:
    • Stomach pain
    • Bloating

There are also some people who should NOT take NO supplements because of the associated risks. These people are those with:

  • Liver scarring - NO can worsen liver function
  • Low blood pressure - NO may further lower blood pressure

If you have any kind of diagnosis, it’s best to consult a doctor first if it’s safe for you to consume NO supplements.

How Does Nitric Oxide Supplementation Compare to Other Testosterone-Boosting Methods?

NO supplements will help your body produce more NO — which is only one step in improving testosterone levels.

But if you don’t lack NO, the supplements might not be too effective.

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Instead, you can try other testosterone-boosting methods.

Testosterone booster supplements are known to increase your levels of testosterone. They contain ingredients like vitamin D that stimulate hormones and processes that produce testosterone.

Doctors can also suggest testosterone replacement therapy (TRT). This treatment replaces the hormone through an outside source (such as gels and injections).

Of course, another way to address low testosterone is to make healthy lifestyle changes.

For example, exercise helps with weight loss and stimulates growth hormone production — both of which can boost serum testosterone concentrations.

How To Take Nitric Oxide Supplements for the Best Results?

If taking NO supplements is something you want to try, here’s how you can make the most of it:

What Is the Optimal Dosage of Nitric Oxide for Testosterone Enhancement?

The maximum recommended dose of NO supplements is 20ppm.

If you take more than the recommended dosage, you might experience side effects.

It’s even more important to know that it’s easy to boost NO levels naturally. You can do so through exercise and consuming the right foods — such as beets, dark chocolate, and even red wine!

You can begin taking NO supplements at a low dosage and then work your way up.

When Is the Best Time To Take Nitric Oxide for Maximum Effectiveness?

Your NO levels are lowest in the evenings, so it’s best to take those supplements at night.

Alternatively, NO levels are also quite low in the mornings. So if you find yourself falling asleep in the middle of the day, NO supplements in the morning may help you.

But if you exercise, you might want to take the supplements 90 minutes before you start.

Regardless, make sure you only take it once a day to prevent the risk of overdosing.

How Long Do the Effects of Nitric Oxide Supplementation Last?

Most supplements boost your NO levels for an hour to an hour and a half.

The boost will last so long as the supplement is still in the bloodstream. Then the effects will wane as the supplement gets metabolized.

Is Nitric Oxide Supplementation Safe for Long-Term Use?

As long as you follow the recommended intake, taking NO supplements can be safe in the long term.

Does Nitric Oxide Affect Testosterone? (Evidence-Based Research) 5

However, be mindful of the ingredients of the NO supplement you choose.

That’s because the FDA regulates supplements as food, not drugs. That means things like purity, potency, and the effectiveness of any claims are left unchecked.

So if you’re going to get an NO supplement, it’s best to choose one that’s been tested by a third party — preferably the NSF Certified for Sport program and Informed Choice for Sport.


NO is quite big in the bodybuilding community, so we answered a few more questions that can help you understand NO more.

Is Nitric Oxide a Testosterone Booster or a Hormone?

Surprisingly, it’s both. It addresses low testosterone by improving blood vessel health. At the same time, studies suggest that NO does function as one of the endocrine hormones.

Are Nitric Oxide Boosters Bad for You?

As long as these boosters contain natural ingredients, they shouldn’t be bad for you. But you’ll want to research what they contain first before committing to them. Remember to take only the recommended dosage that you can find on the bottle label.

What Happens with Too Much Nitric Oxide?

Too much NO can mess with your brain function, causing migraines and possibly neurodegenerative diseases like Parkinson’s and Alzheimer’s. You can also experience diarrhea, stomach pain, and kidney problems, among other things.

What Does Nitric Oxide Testosterone Booster Do for Males?

It can address low testosterone by nudging hormones needed to produce testosterone. At the same time, it improves the flow of blood, which can help manage erectile dysfunction.

What Is Nitric Oxide Testo Booster Used for in Bodybuilding and Can It Stimulate Muscle Growth?

NO supplements are seen as pre-workout supplements. They improve your energy levels so you can keep up with your workouts. They can also help your blood deliver more oxygen and nutrients to your muscles and thus support muscle growth. So yes, NO boosters also help stimulate muscle growth.

Can You Take Nitric Oxide with Testosterone Booster?

Yes, you can take NO with a testosterone booster! In fact, there are companies that sell the two supplements as a bundle.


NO is being marketed as a supplement that can improve testosterone levels and athletic ability.

There isn't much scientific evidence that completely backs up NO’s effectiveness. However, there are users who do claim that it does work.

There’s no harm in trying it — just make sure to follow the recommended dosage and combine the supplement with other healthy habits that can boost your testosterone levels!

  1. Raúl Bescós, et al. “The Effect of Nitric-Oxide-Related Supplements on Human Performance.” ResearchGate, Springer Verlag, Feb. 2012,
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