Why you should consider L-Citrulline, not L-Arginine

Why you should consider L-Citrulline, not L-Arginine


The Takeaway First

Taking L-Citrulline (Citrulline) can help increase your levels of Nitric Oxide, a compound that helps us open our arteries and improve circulation. Anything that helps improve Nitric Oxide production is a really good thing. The result of widening our arteries includes many good physiological responses including: lower blood pressure, improved blood vessel health and youthful erections in men.

The Details

Our bodies are complicated machines. They need an unimaginable variety of chemicals to function. One of the most important of these chemicals is Nitric Oxide, which, according to recent research, has specific health benefits for people with erectile dysfunction. As I’ve blogged before, Nitric Oxide (NO) helps your blood vessels to relax and carry blood to the major organs. It’s especially helpful for males because it plays a big role in the chemical reaction that makes and maintains an erection.

One way that your body produces Nitric Oxide is by breaking down Citrulline, a non-essential amino acid. Fortunately for us, L-Citrulline is easy to find in supplement form as well as in everyday foods such as watermelon. The problems is that it takes quite a lot of watermelon to get enough L-Citrulline.

How exactly does the process work? In short, Citrulline is converted in the body to L-Arginine (Arginine), an important nutrient in making Nitric Oxide .

In fact, oral intake of Citrulline makes more Arginine in the body than oral intake of Arginine alone.

In other words, if you want more Arginine, take Citrulline not Arginine.


The Benefits and the Science

For being a “non-essential” amino acid, L-Citrulline has clear benefits. One of these benefits is, as I hinted above, an improved ability to get and keep an erection (Hotta et al. 2014). Taking L-Citrulline as a supplement has shown to increase Nitric Oxide levels and cardiovascular function in people with cardiovascular diseases associated with endothelial dysfunction, such as hypertension, heart failure, atherosclerosis, diabetic vascular disease, and ischemia-reperfusion injury (Romero, Platt, Caldwell & Caldwell 2006). However, these benefits unfortunately might not last long term.

New research has investigated whether it’s better to take L-Citrulline or its derivative, L-Arginine, and the results are clear. While L-Arginine at normal doses make little positive impact on the L-Arginine levels in body tissues, L-Citrulline makes more of an impact (Wijnands et al. 2012). L-Citrulline increased Nitric Oxide and L-Arginine levels in the blood and the tissues of the study participants.

For the majority of non-elite athletes, taking L-Citrulline could be a special boost. When untrained or moderately healthy subjects took Nitric Oxide donors like L-Citrulline, their tolerance to aerobic and anaerobic exercise improved (Sureda & Pons, 2012). In elite, heavily-trained athletes who took the supplement, the researchers did not find the same effects.



My Take on This

Citrulline is slowly making its way to one of my top 10 supplements to take.

Let me repeat a general rule about dietary supplements: they’re not worth your time if your lifestyle is out of whack. The most important principle of good health and a robust sex life is make healthy choices every day. Get moving, stop smoking, stop spending so much time sitting down, and eat well.

Properly balanced dietary supplements complements good health habits really well.

The Bottom Line

If you are one of the many men who are conquering effects of aging, especially ED, it may be worthwhile to investigate Citrulline’s place among your supplement regimen. To improve circulation, I would recommend a fine balance of L-Citrulline, Rhodiola, Pomegranate and Resveratrol – all good for artery health and better blood flow.



Hotta Y, Shiota A, Kataoka T, Motonari M, Maeda Y, Morita M, Kimura K. Oral L-citrulline supplementation improves erectile function and penile structure in castrated rats. Int J Urol. 2014 Jun; 21(6):608-12.

Romero MJ, Platt DH, Caldwell RB, Caldwell RW.Therapeutic use of citrulline in cardiovascular disease. Cardiovasc Drug Rev. 2006 Fall-Winter; 24(3-4):275-90.

Sureda A, Pons A. Arginine and citrulline supplementation in sports and exercise: ergogenic nutrients? Med Sport Sci. 2012; 59:18-28.

Wijnands KA, Vink H, Briedé JJ, van Faassen EE, Lamers WH, Buurman WA, Poeze M.Citrulline a more suitable substrate than arginine to restore NO production and the microcirculation during endotoxemia. PLoS One. 2012;7(5):e37439.


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