L-Citrulline or Citrulline Malate?

Citrulline is closely related to the production of nitric oxide in the body, and we have kept that in mind ever since we learned how the supplement reacts in the body; but now we wonder, which form of citrulline increases performance? L-citrulline or citrulline malate? Citrulline goes alongside arginine in many pre-workout formulas, but arginine is often left behind in the specific formulation; at least many brands give citrulline the leading role.

What happens is that, in the body, citrulline acts as a precursor of arginine, that is, it is used in the production of arginine, which ultimately stimulates the production of nitric oxide (NO), which acts as a vasodilator to open the blood vessels and increase blood flow to the muscle. So why not take arginine instead? In short, arginine is subject to a more rigorous digestive route, passing through absorption in the small intestine and the liver before being released into the bloodstream.

Citrulline, by contrast, can bypass all of this and go straight into the bloodstream, where it can increase nitric oxide production; the ironic result of all this is that citrulline ends up being a better booster of arginine levels in the blood than arginine itself, and without side effects such as some digestive discomfort for some people, although this relates to biological individuality, so everything is relative when we ask ourselves the question L-citrulline or citrulline malate?.

But not all citrullines are the same; looking at ingredient labels, we realise that the industry focuses on two types of citrulline, L-citrulline and citrulline malate. What we will do now is contrast what the research says and which of them is more suitable for certain goals.

The particularities of L-citrulline

L-citrulline is the natural form of citrulline; although the body produces its own supply, consuming extra citrulline can have significant performance advantages. The compound, which occurs naturally in fruits such as watermelon, plays a role in two important processes; on the one hand, it helps increase nitric oxide levels, which dilates the blood vessels, allowing more oxygen and nutrients to be delivered to the muscles, and on the other hand it helps remove ammonia from the blood, a compound known to cause exercise-related fatigue.

Studies on L-citrulline or citrulline malate? have reported that citrulline malate raises energy, oxygen consumption and athletic performance with a minimum of 2.4 grams per day over a period of eight days. In addition, supplementation with citrulline plus the antioxidant glutathione for seven days, according to other studies, leads to an increase in nitric oxide markers in repeated sets during an intense workout; although, in certain maximal-effort routines, L-citrulline may cause certain negative effects, which is why some competitive athletes avoid it when facing a truly hardcore session.

What can we say about citrulline malate

The only difference between L-citrulline and citrulline malate is the addition of malic acid; this may seem a minor detail, but it is an important component of the tricarboxylic cycle, which is one way the body produces energy; when malate levels increase, energy production increases, therefore citrulline malate provides the dual function of delivering that additional blood and, subsequently, oxygen and nutrients to the muscles that move during a contraction, as well as providing an energy boost to raise performance levels.

Research on citrulline malate is relatively new but promising; we cite, for example, a recent study published in the European Journal of Sport Science stating that consuming 8 grams of citrulline malate before exercise provides an increase in maximal grip strength and improves explosive power of the lower body. Another study carried out with professional weightlifters found that 8 grams of citrulline malate increased the number of repetitions taken to muscle failure, observed after several sets of lower-limb exercises.

In addition to its effects on performance, citrulline malate may also reduce post-workout muscle soreness; research published in the Journal of Strength and Conditioning Research found that taking 8 grams of citrulline malate one hour before completing several sets to failure on the bench press led to a significant decrease in muscle soreness, which became widespread in more than a hundred trials in the same setting.

And the winner is…

Both have their strengths, but the victory in terms of performance goes to citrulline malate; the key difference is its ability to increase both muscle pump and performance, which means more repetitions, greater effectiveness in the gym, and better results. Another advantage of using citrulline malate is that you do not have to load it frequently, whereas L-citrulline is more effective after a week of constant use; that means it can be taken right before training and you will feel its performance benefits immediately.

Whether we decide on L-citrulline or citrulline malate, it is always best to take the correct dose; if you opt for L-citrulline you can take 2.4 to 6 grams for a minimum of 7 days, while citrulline malate shows its effects with 6 to 8 grams about an hour before intense training, with no need for a loading phase.

Sources

1. Bodybuilding.com: L-Citrulline or Citrulline Malate ? N.O. Contest !
2. Journal of the International Society of Sports Nutrition: Oral L-citrulline supplementation
3. Journal of Applied Physiology: L-citrulline supplementation improves O2