What Does L-Citrulline Do in Pre-Workout? It’s Important

Reading the ingredient label of a pre-workout is a necessary skill of every gym-goer, strength athlete, or bodybuilder, so let’s start with the following:

What does L-citrulline do in a pre-workout?

What is L-Citrulline in Pre-Workout?

To put it simply, L-citrulline is the second most important ingredient in a pre-workout.

First is obviously caffeine.

The role of L-citrulline in a pre-workout formula is rather simple – it improves vasodilation (blood flow) and increases muscle pumps.

We’ll discuss this in greater detail a bit later.

It also increases performance, improves stamina and endurance, and helps you feel a bit better tomorrow. [1]

We’ll also discuss this in a second.

What Does L-Citrulline Do When Taken Pre-Workout?

What L-citrulline does in a pre-workout is improve vasodilation by stimulating nitric oxide production.

L-citrulline is a precursor to L-arginine, an amino acid that directly stimulates nitric oxide production.

Nitric oxide is the gas responsible for the widening of the blood vessels and increased blood flow to the muscles.

This increased blood flow results in better oxygen and nutrient delivery, improved muscle pumps, and an overall better performance during your workout across all of the abovementioned parameters.

So, what does it do? It does A LOT.

Benefits of Taking L-Citrulline Pre-Workout

Since we’ve already explained the effects of L-citrulline on your body, let’s now focus on the actual benefits you’ll get to reap.

But before we get to those – a piece of advice.

If a pre-workout formula doesn’t contain any L-citrulline – skip it.

At that point, you’re better off popping caffeine pills than wasting your money on a pre-workout.

Now, the benefits.

It’s widely considered that the “last rep” you pull out of yourself when performing any of the exercises in the gym is the “rep that matters the most“.

Now, that is a gross oversimplification of how muscle-building works, but it’s not too far from the truth.

Seeing how citrulline helps you offset fatigue and improve your overall anaerobic performance, it’s quite probable that you will be able to pull out not one but a few of these “last reps” over the course of your session, effectively boosting your chances of developing that desired physique, improving your strength, losing weight, or whatever other goal you may have.

Furthermore, L-citrulline reduces post-workout soreness, which might not seem like a lot, but being able to actually move tomorrow or the day after might just be a push you need to get into the gym and train another muscle group.

Will L-Citrulline Give You a Better Pump?

Yes, L-citrulline will give you a much better pump.

In fact, there’s an overwhelming amount of evidence suggesting that citrulline is arguably the best pump booster that you can get your hands on.

What’s the Best Dosage for L-Citrulline in Pre-Workout?

The best dosage for L-citrulline in a pre-workout is 6 to 8 grams per serving. However, the optimal dose for you could be lower or higher depending on your body weight and other factors.

But there’s a lot more to unpack here.

First, you must understand that (most) supplement companies are arguably the greediest people on the planet.

They cut corners, lie, scheme, and withhold information just so they can make a bigger profit.

Here’s how they do it with L-citrulline.

L-citrulline or citrulline is sometimes mixed with DL-malic acid in order to create a compound called citrulline malate or L-citrulline malate. This compound is thought to be more bioavailable than citrulline itself, hence the effort to put them together.

However, this binding process is not easy, and it costs money. So instead, companies just put the two together in a batch, mix it up and call it a day.


With real citrulline malate (chemically bonded compound) – you get what you pay for. In other words, when the label reads “Citrulline malate – 6g”, you’re actually getting 6 grams of citrulline.

The mix-it-all-up “citrulline malate”, on the other hand, is equal parts (unless stated otherwise, could be 2:1 or 3:1) citrulline and malic acid. Therefore, when you read “Citrulline malate – 6g”, you’re getting 3 grams of citrulline, which is not an effective dose.

The sad part is, you can’t know if the “citrulline malate” listed on the ingredients list is real or just a cheap cop-out on a technicality.

So, what you should do instead is look for a pre-workout that lists citrulline and malic acid as separate ingredients.

Only then you can be sure.

Are There Any Side Effects of Taking L-Citrulline Pre-Workout?

Pre-workouts have quite a few side effects associated with them, regardless of whether they contain citrulline or not.

Side effects include:

  • Jitters
  • Itching
  • Nausea
  • Upset stomach
  • Sleep issues

However, neither of these is associated with citrulline.

Most of them are the result of caffeine, beta-alanine, or other ingredients often included in pre-workouts.

Does Your Pre-Workout Really Need to Have L-Citrulline?

Yes, a pre-workout must contain L-citrulline – as we’ve already established.

It definitely needs to be on there, and it needs to be properly dosed if you want to experience all the benefits it yields.


Now that you know what L-citrulline does and why it’s so important for pre-workouts, you can make an informed decision the next time you go shopping.

Just make sure you pay close attention to the back f the label. Got it?

What to Read Next

L-Glutamine Pre-Workout – Is it Necessary Before a Workout?
L-Glutamine Pre-Workout
What Does Alpha-GPC Do in Pre-Workout? – Is it Worth Using?
What Does Alpha-GPC Do in Pre-Workout
Share This Post

Providing you with the resources to build your best life and physique.

Articles: 125

Leave a Reply

Your email address will not be published. Required fields are marked *