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How Do Arginine + Citrulline Produce Nitric Oxide?


If you’ve ever taken a pre-workout, chances are you’ve heard of arginine, citrulline or sodium nitrate. One or all of these ingredients are commonly featured in formulas that claim to increase nitric oxide production and boost performance. But how does this actually work? Read on to learn how these ingredients make it happen and what it means for you and your workout.


Nitric oxide is a vasodilator, meaning it improves blood flow by prompting blood vessels to open wider. Healthier blood flow means more oxygen and nutrients are delivered to your muscles, which is especially important during exercise. Supplements don’t contain nitric oxide itself, but rather substances that your body uses to produce it. Those substances are arginine, citrulline and nitrates.


Arginine is a key amino acid and a building block in the production of nitric oxide. Your body uses a metabolic pathway to convert arginine into nitric oxide. Arginine fuels nitric oxide production, which in turn enhances blood flow and helps maintain your blood vessel tone.


Like arginine, citrulline is an amino acid. Citrulline can be recycled to arginine via the citrulline-N.O. cycle and works with arginine to help fuel muscle cells and support your body’s production of nitric oxide.


Nitrates, found in certain foods or as a dietary supplement, can also be converted to nitric oxide, especially during times of decreased oxygen availability (think high-intensity exercise). They also have the potential to assist in oxygen delivery to working muscles. Certain vegetables, such as spinach, beet root and celery, have high concentrations of nitrate. Because soil concentrations vary, however, it’s difficult to determine just how much you will get from these vegetables. Now that you’re an expert on nitric oxide and its building blocks, look for them in your pre-workouts!

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