Citrulline: Improve Performance Naturally

As a society, we must focus on clean, natural intake of essential nutrients to optimize our health and physique. If you have ever been interested in improving your physical performance through your nutrition, you have most likely heard of the amino acid citrulline specifically, L-citrulline. This amino acid has been touted as a powerful supplement to improve your performance in your desired physical activity. But how exactly does this amino acid benefit your health, and are there other natural sources within superfoods like watermelon that can give you better citrulline content? Let’s explore the history behind citrulline and superfoods that can lead to cleaner optimization of the body.

L-Citrulline & Nitric Oxide

L-Citrulline is a non-essential amino acid that is transformed naturally in the body to the essential amino acid arginine. Both citrulline and arginine play an important role in the synthesis of nitric oxide, which helps lower blood pressure through vasodilation (the opening of blood vessels which decreases blood pressure), antioxidant activity, and relaxation of your blood vessels.

Nitric oxide is important in maintaining and relaxing your blood vessels to keep them flexible, boosting blood flow, decreasing blood pressure, and promoting reconstruction after injury. It even helps in everyday instances such as muscle breakdown during and after exercise. Nitric oxide has anti-inflammatory properties and helps prevent platelets and white blood cells from sticking to the inside of blood vessels, thus reducing the risk of plaques.

As we age, our cells produce less nitric oxide, so blood vessels become less flexible, which contributes to hypertension (high blood pressure), inflammation in blood vessels, and atherosclerosis (plaque buildup). This leads to cardiovascular disease, causing a vicious cycle of increasing blood pressure, inflammation, and atherosclerosis that impairs the production and action of nitric oxide.

So how can we combat the natural cycle of aging which impairs the action of nitric oxide through the amino acids citrulline and arginine? The key solution could be to optimize the foods we consume to enhance our performance and bodies.


Superfood – Watermelon

Watermelon is a natural superfood and rich source of both the amino acids citrulline and arginine. Regular consumption of this food can increase your blood levels of these amino acids. Specifically, watermelon is the richest known dietary source of the amino acid citrulline. The highest concentration is found in the white rind that surrounds the flesh of the fruit.

Not only is watermelon a good source of citrulline and arginine, but it is also rich in vitamin A, B6, C, carotenoids, and is a good low-calorie libido-boosting food.

Health Benefits of Watermelon

Now we know the contents of watermelon and why it is considered a superfood. The question remains, how does implementing watermelon in our nutrition positively impact our health and well-being?

Nitric oxide is a well-studied pathway because it is the target of many drugs like sildenafil, commonly known as Viagra. To reduce the use of medications like Viagra, we must look to natural resources in our food to help strengthen our performance. Watermelon can help improve sexual performance due to its role in blood vessel relaxation, causing more blood flow to your sex organs. Specifically, researchers have studied the potential use of watermelon to combat symptoms of Erectile Dysfunction (ED) due to the high concentrations of citrulline that convert to nitric oxide.

Citrulline also has properties that lower your blood pressure through its vasodilation. In turn, your blood vessels are under less stress, so your blood pressure levels decrease or are easier to maintain. Optimizing L-citrulline levels through foods such as watermelons, spinach, or citrus fruits may be beneficial for individuals with prehypertension and hypertension.

Research has also shown that citrulline intake through watermelon and their juice may aid in reducing insulin resistance. Insulin is an essential hormone involved in controlling your blood sugar levels after a meal. Insulin resistance is the condition in which your cells become resistant to the effects of insulin’s natural process in lowering your blood sugar levels. As a result of this, it can lead to elevated blood sugar levels that are linked to metabolic syndromes and type 2 diabetes.

Studies have shown that watermelon and its juice are impactful at decreasing muscle soreness following exercise. Research on watermelon juice and exercise performance is still in progress, with new studies coming out.

Citrulline is a precursor amino acid to nitric oxide that regulates the activity, growth, and death of many immune and inflammatory cell types. A reduction in nitric oxide production can reduce blood flow to the brain, as well as possibly increase inflammation and oxidative stress, which contributes to cognitive issues. While overproduction of nitric oxide in the lining of blood vessels can regulate a protein that is a precursor to amyloid (found in plaques that is a staple finding of Alzheimer’s disease).


Healthy Watermelon Recipe


Table of Citrulline-Rich Foods

Watermelon Arugula
Beets Kale
Cabbage (Red and Green) Lemon
Lime Pure Dark Chocolate
Garlic Orange
Grapefruit Spinach

Acquire and understand the health benefits of the amino acid citrulline through natural nutritional supplementation. Harnessing the potential power behind superfoods such as watermelon, which has the highest concentration of citrulline, can improve your performance and overall health.

Interested in improving your health and well-being? Learn more about how our Healthoscopy™ Solution can help you!




l-Citrulline Supplementation: Impact on Cardiometabolic Health, Allerton, T, D (Pennington Biomedical Research Center) 


Physiological and clinical importance of nitric oxide, Madan, G (Cone Behavioral Health) 

The Nitric Oxide Pathway in Pulmonary Vascular Disease, Klinger, J, R (Alpert Medical School of Brown University) 


Watermelon, raw, Staff (USDA) 

Why Nitric Oxide Is So Important, Staff (BerkeleyWellness) 

Will taking arginine and citrulline protect my arteries?, Staff (Harvard Health Publishing) 

Click here to see your activities