One is an essential amino acid, one is not, however put the two together and you’ve got an amazing duo for maintaining a healthy heart. We spend a lot of time talking about arginine in foods and supplements, and the remarkable qualities that arginine has in terms of vasodilation and heart disease. However, if you’re talking supplements to increase blood flow and maintain a healthy heart, you’ll need more than just an arginine pill a day.


Citrulline is a non-essential amino acid; meaning that you’re body does not necessarily need this organic compound to function. It’s incredibly abundant in watermelon, actually taking its name from this food. This amazing little compound has been used for Alzheimer’s disease, dementia, fatigue, muscle weakness, sickle cell disease, erectile dysfunction, high blood pressure, and diabetes, according to

Citrulline has been researched in association with reducing high blood pressure in children after heart surgery, and improving symptoms of sickle cell disease.

The Dynamic Duo

Citrulline, once in the body, is converted into arginine, which then facilitates in the production of nitric oxide, a key element in relaxing blood vessels and increasing healthy blood flow. Together, arginine and citrulline have some amazing benefits, including supporting healthy blood pressure, boosting the immune system, detoxifying the liver, and enhancing workout recovery time.

In a 2010 study published in Sports Medicine, researchers evaluated athletes and exercise performance while taking arginine and citrulline supplements, and not taking the supplements. Overall, they notice a slight increase in “exercise performance” in the group that took the dynamic duo supplement.

In a separate study published in the same year in the Journal of Strength & Conditioning Research, the dynamic duo was shown to increase weightlifting performance and delay muscle fatigue in weigh training.

Citrulline and arginine were also studied in association with immune system levels. Professional cyclists who took the citrulline supplement before a race increased their arginine levels, which increase their neutrophi immune cell levels; a crucial component of a healthy immune system. When endurance athletes finish an intense workout or race, their immune defenses drop dramatically. However, this study showed how citrulline and arginine improved their after-race immune defenses.

Taken Together….

Taken separately, citrulline and arginine can still be incredibly beneficial to help maintain a healthy heart. However, taken together, these two organic compounds can offer a one-two punch, facilitating a healthy heart and strong immune system. To achieve the maximum benefit of nitric oxide and amino acids, it is best to combine citrulline and arginine, as we’ve done in Cardio Juvenate!