Alternative Title: L-Citrulline Benefits
L-Citrulline is an amino acid that is converted to L-Arginine, which is then converted to Nitric Oxide (NO). Nitric oxide is a vasodilator, which widens blood vessels, capillaries, and arteries. This increases the delivery of blood to tissues and circulation, and saturates certain areas with blood. This also decreases blood pressure. During exercise, nitric oxide is increased in response to the elevated demand for blood and oxygen. This is responsible for the increased vascularity following exercise (alongside elevated body heat) and contributes to the pump.
Nitrates, which convert to nitrites in the body, are also converted to NO. Beets or beetroot powder, as well as red spinach, are rich in nitrates. This is how they achieve their circulation and vasodilatory effects. Nitroglycerin, which contains nitrates, was and still is prescribed for the treatment of high blood pressure and angina.
L-Citrulline -> L-Arginine -> NO
Nitrates -> Nitrites -> NO
L-citrulline has been popular as a sport supplement and for bodybuilding for many years because of these performance and cosmetic benefits. Bicep and forearm vascularity is increased by l-citrulline as stated. The vasodilation and increased circulation has many other applications and benefits.
It has been shown that l-citrulline is superior to l-arginine in increasing circulation, vasodilation, and arginine levels itself due to improved efficiency, bioavailability (absorption), and reduced side effects (i.e. gastrointestinal irritation). Supplements and preworkouts typically use citrulline as Citrulline Malate, which is bound with Malic Acid, or pure L-Citrulline. Citrulline and L-Citrulline are the same thing for clarity, with the latter typically used in the context of supplements to distinguish it from Citrulline Malate.
Whilst nitric oxide can have negative health implications, context is key. Nitric oxide during exercise or from supplements is vastly different in effect and practice than during conditions, diseases, and deficits. In addition, like all things, balance matters just like too much sun or too much oxygen is harmful.
A typical dose of L-Citrulline is 5g.
As Citrulline Malate, a serving is typically around 8g, providing about 5g of L-Citrulline depending on manufacturing formula.
L-Citrulline Benefits
Circulation
Vasodilation caused by L-citrulline helps improve and accelerate circulation. Conditions where blood flow is impaired, such as muscle tension or sitting down for extended periods of time, could benefit from L-citrulline. Enhanced circulation also provides many other benefits indirectly, including improving immunity, reducing inflammation, increasing recovery or growth, and longevity.
Vascularity
L-citrulline increases vascularity through vasodilation, causing the blood vessels to widen and rise to the surface. The vascularity on your forearms and biceps after working out are an example of this, where increased body heat and NO causes them to surface from their size, as well as to cool the blood and body. This is more of a cosmetic benefit but can be nice for photoshoots, and everyday appeal. You feel how you look, or, this also helps you feel more confident, powerful, and thus more expressive, driven, and focused.
Blood Pressure
Since L-citrulline dilates blood vessels, it can reduce blood pressure just like nitroglycerin and beetroot. This of course can be helpful for high blood pressure, or contexts where blood pressure might be increased like certain physical activities. Gymnastics or pose-related activities, where the muscles are put under tension for periods and the body constricted, and thus blood flow reduced, would benefit from vasodilation allowing blood to flow evenly and consistently. In a more unique way, this effect can benefit holding these postures, poses, or tension for longer by allowing the muscles to receive ample blood flow and oxygenation just like normal endurance benefits.
Endurance or Stamina
Enhancing the delivery of blood, nutrients, and oxygen improves endurance and stamina. Increased circulation also improves the removal or breakdown of lactic acid in muscles, reducing and delaying the burn with weightlifting, running, or sports. Part of the panting and heavy breathing with endurance exercise comes from the muscles demanding more oxygen, when your lungs have enough oxygen but the actual delivery and circulation of oxygen is the bottleneck. Better circulation and blood flow means less heavy breathing, and thus more endurance.
Cognitive Function
L-citrulline can improve cognitive function. The brain is an organ and tissue like any other, and thus requires circulation and blood flow to function. L-citrulline improves cognitive function by increasing circulation to the brain, improving oxygenation, and accelerating nutrient delivery. Gingko biloba and vinpocetine are prominent nootropic supplements which work in large part by increasing blood flow to the brain, and have also been shown to improve memory and neurological conditions like Dementia. Whilst the pro-cognitive effects of L-citrulline might not be as pronounced as these, its effects are sure to support functions like focus, clarity, brain fog, memory, and more.
