Best Pre Workout Ingredients: Citrulline

L-citrulline is one of the most popular ingredients in pre workouts, routinely praised for its ability to enhance nitric oxide production, performance, and pumps.

But, what exactly is L-citrulline and, how does it do what it does so well? Furthermore, what’s the “ideal” dose for L-citrulline to reap the rewards of this perennial pre workout supplement?

Let’s find out!


L-citrulline is a non-essential amino acid, which means your body is capable of synthesizing it in sufficient amounts. This also means you don’t necessarily need to get citrulline from foods like you would an essential amino acid or branched-chain amino acid, such as Leucine.

Physiologically speaking, L-citrulline is a key player in the Urea cycle, which is the process whereby the body removes toxic byproducts (i.e. ammonia) resulting from protein digestion and cellular energy production.

More pertinent to the sphere of pre workouts and pumps, L-Citrulline enhances nitric oxide production and blood flow by increasing blood arginine levels. In the body, L-arginine is the amino acid used as the “fuel” to power the production of NO.

Years ago, it was believed that supplementing with L-arginine would increase blood arginine levels; however, arginine suffers from terrible bioavailability in the body.

L-citrulline, on the other hand, has been well-documented to significantly boost blood arginine levels better than even L-Arginine supplementation. This is due to the fact that L-Citrulline resists breakdown in the stomach and makes it all the way to the kidneys, where it is then converted to arginine.

This provides a superior method for boosting NO production in the body, leading to greater blood flow, performance, and pumps.


  • Improves athletic performance
  • Supports cardiovascular health
  • May help improve symptoms associated with ED
  • Reduces free radical damage
  • Massive muscle pumps!


To experience the NO-boosting effects of L-citrulline, research indicates you need to ingest a minimum of 2.4 grams prior to exercise.

Killer Labz Destroyer contains 3g of pure L-citrulline, which is the perfect dose to help you train longer and harder during your workouts while experiencing less fatigue and muscle pumps. You’ll also get some killer pumps, too!