L-Citrulline: More Reps, Bigger Pumps, Greater Gains


If you’re reading this article, you’ve probably heard of L-Citrulline.  But do you really know what it is and how it works?  Most people think L-Citrulline is just a “nitric oxide supplement”.

If you’e explored the research, however, you would have found out that it’s actually so much more.  Well, not to worry.  That’s what we’re here for…

In this article, we’ll answer questions like:

  • What Is L-Citrulline?
  • What Are The Proven Benefits?
  • Which L-Citrulline Supplement Is Best?

And go over things like:

  • L-Citrulline Dosing
  • Is It Safe?

And a whole lot more!  So let’s just get started then…

What Is L-Citrulline?

L-Citrulline amino acid molecule

L-Citrulline is a non-proteinogenic, non-essential amino acid. This means it isn’t used to make proteins, and can actually be produced by the body, but make no mistake…

It’s extremely useful as a supplement.

It’s a precursor to the amino acid, Arginine, giving it a critical role in Nitric Oxide production.  This has earned Citrulline a reputation as a “pump enhancer”, but it’s actually much more than that.

Citrulline also plays a role in the Urea Cycle, a detoxification process by which Ammonia is converted into Urea and expelled from the body.  This role is what underlies the performance enhancement benefits of Citrulline…

What Are The Proven Benefits Of L-Citrulline?

L-Citrulline Proven Benefits

Although it’s relatively unknown to most people, L-Citrulline has actually been studied fairly extensively over the years.  Especially with regards to exercise.

At this point, numerous benefits have been proven and then proven again…

L-Citrulline Increases Muscular Endurance

First and foremost, Citrulline has been shown to increase muscular endurance.

More specifically, it increases the amount of reps you can do towards the end of your workout, when muscular fatigue would ordinarily be setting in.

You see, muscle fatigue is partially caused by Ammonia build-up in muscle tissue.  Citrulline, being a key player in the Urea Cycle, can reduce the amount of Ammonia that builds up in muscle tissue.

That means more reps for more sets and of course, greater gains over time!

L-Citrulline Promotes Better Pumps

Remember earlier when we talk about how Citrulline is the direct precursor to the amino acid L-Arginine which is a the immediate precursor to Nitric Oxide.

Anything that increases Nitric Oxide levels can potentially increase blood flow, causing some pretty nice pumps during workouts.  Unfortunately, most “nitric oxide supplements” don’t really work.

L-Arginine is a perfect example.

One would think that, since Arginine is actually closer to Nitric Oxide than Citrulline, supplementing with Arginine would be a better idea.  Makes sense, but it isn’t true.

Studies which have looked at how Arginine impacts performance enhancement, blood flow, and nitric oxide production have failed to find any real benefit.

This is because Arginine is subject to breakdown by the enzyme Arginase.  L-Citrulline, on the other hand, is not.  It bypasses this enzyme, then converts into Arginine which converts into Nitric Oxide.

If it’s better pumps you’re after, you want L-Citrulline.  Not L-Arginine (or any other kind of Arginine).

L-Citrulline Improves Cardiovascular Health

Given it’s role in increasing blood flow, it makes sense that Citrulline would be explored as a potential treatment for people with cardiovascular conditions.

It has been shown to prevent increases in Blood Pressure, but does not lower Blood Pressure in healthy people.  In other words, Citrulline helps maintain healthy Blood Pressure but won’t drop it too low, as many Blood Pressure medications can do if you take too much.

This makes it a natural and safe first line of defense against high blood pressure.

It’s been shown to prevent hypertension in kids recovery from heart surgery but also appears to encourage healthier heart function in healthy individuals.

L-Citrulline Helps With Erectile Dysfunction

Naturally, anything that increases blood flow is going to attract the interest of Erecetile Dysfunction researchers.  After all, around 50% of men have ED at some point.

L-Citrulline supplementation has been shown to improve symptoms of ED, even at 1.5 grams daily.  The same dose of L-Arginine has actually failed to have any impact on ED.

So yeah, if it’s harder boners you’re after, L-Citrulline is the way to go!

L-Citrulline Reduces Muscle Soreness

One of the most intriguing benefits of L-Citrulline is that which pertains to recovery from exercise.

It’s actually been shown to reduce muscle soreness.  Although this was originally more of a positive side effects noted in one study, several other studies have now confirmed it.

Citrulline definitely reduces muscle soreness.  How exactly it works though, remains something of a mystery…

L-Citrulline And Growth Hormone

Growth Hormone (GH) is involved in a ton of physiological processes including building muscle, burning fat, and supporting immune function.  When you exercise, you naturally secrete more Growth Hormone.

Combined with exericse, L-Citrulline supplementation has been shown to augment the increase in Growth Hormone.  It does not appear to be effective without exercise.

Also, it’s not clear whether the increase in large enough to really matter in the scheme of things.  Most supplements that “increase Growth Hormone” really only do it to a small degree and for a short period of time.

Citrulline supplementation won’t mimic the effects of taking GH or anything even close to that.

L-Citrulline May Be Synergistic With Leucine

Leucine is the most important amino acid when it comes to building muscle.  It directly stimulates mTOR, a signaling molecule which tells the body to start building proteins.

There is some preliminary evidence which suggests Citrulline may enhance Leucine’s signaling of mTOR.  This could potentially mean that Citrulline is synergistic with Leucine.

This area is particularly under-researched though.  We need a few more studies before drawing any solid conclusions about how Citrulline actually interacts with Leucine.

That said, it makes sense to include Citrulline anytime you’re supplementing with Leucine, especially if it’s for fasted cardio.  That’s why I included 6g of Citrulline Malate along with 4g of Leucine when I formulated Amino Beyond.

The Different Types Of Citrulline Supplements

Citrulline Supplements

You’ll typically find 2 types of L-Citrulline supplements:

  1. L-Citrulline
  2. L-Citrulline Malate

L-Citrulline is what we’ve been talking about.  It’s just Citrulline.  L-Citrulline Malate is L-Citrulline bonded with Malic Acid.  Malic Acid plays a role in energy metabolism in the body.  It may have it’s own inherent benefits, but no studies have really looked at Malic Acid supplementation alone.

However, the majority of the studies in which Citrulline enhance exercise performance and reduces soreness used L-Citrulline Malate.  So, that’s the recommended form.  Citrulline Malate is usually in a 2:1 ratio of Citrulline To Malic Acid.

That means 6 grams of Citrulline Malate would yield 4 grams of Citrulline and 2 grams of Malic Acid.

L-Citrulline Dosing

L-Citrulline Dosing

Studies have used a combination of L-Citrulline and Citrulline Malate but studies pertaining to exercise have gravitated toward Citrulline Malate for whatever reason.

At this point, enough different doses of Citrulline and Citrulline Malate have been used across enough different studies to carve out a clinical dose (range).

  • If you’re taking L-Citrulline, you want to take 4 or 5 grams.
  • If you’re using Citrulline Malate (2:1), shoot for 6-8 grams.

Unfortunately, due to the fact that Citrulline is expensive, most supplement companies under-dose it.  3 grams of Citrulline Malate won’t cut it!  Make sure you’re paying attention to your Supplement Facts panels and only buy clinically dosed supplements with NO proprietary blends.

Is It Safe?

Yes, extremely safe.  At doses of 6-9 grams, absolutely no negative or adverse health effects have ever been reported.  This makes sense since Citrulline is simply an amino acid which your body is not only accustomed to, but requires to function properly.

If you were to take “too much” Citrulline, your body would just simply not absorb it.  The worst thing you could do to yourself with Citrulline is get a stomach ache if you ate like 20 grams in one sitting.

There’s really nothing to worry about with Citrulline.  It’s SUPER safe!

The Bottom Line

If you want to get the most out of each and every workout, you want to supplement with L-Citrulline.  It’s been scientifically proven to:

  • Increase Muscular Endurance (More Reps, More Sets)
  • Reduce Muscle Soreness (Faster Recovery)
  • Increase Blood Flow (Better Pumps)

Not only is L-Citrulline extremely safe, but it can also be considered downright good for you!  Next time you reach for a pre workout or amino acid supplement, make sure it’s got a clinical dose of Citrulline (Malate) in it.  This is one supplement that’s well worth it!

Any thoughts on L-Citrulline?  Comment Below…

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