Citrulline is one of the best ingredients in our supplement arsenal, but it’s possible that many people, even experienced bodybuilders, aren’t using it.
Up until relatively recently, Arginine was considered king of the “muscle pump”, mainly because it plays a critical role in Nitric Oxide synthesis; the key molecule for the process of vasodilation.
Vasodilation is the widening of the arterial blood vessels in and around the working muscles.
When you workout, the muscle swells as a result of the extra blood that can travel through these dilated vessels. This is known widely as “the pump” or getting “swole”.
It’s a natural process. If you’ve lifted weights, you’ve experienced it.
The appearance of being jacked up isn’t the only thing that vasodilation is good for – though there’s a bunch of mirror junkies who don’t really care about anything else.
More blood means more oxygen and nutrients get to the working muscles. That’s what makes it useful.
Did You Know?
Recent research has highlighted that some of the temporary size increase you get in the gym from “the pump” might not be so temporary after all.
Train the muscles to get bigger like this regularly and a small portion of the size increase stays after each workout.
Over time, this adds to the already great increases you are getting from hypertrophic muscle growth due to adaptation to the resistance training.
Cool, huh!?
So…supplements that can provide even bigger pumps (like this) can help you build even more muscle.
Boosting Nitric Oxide
A long time ago, some clever souls figured out that a certain amino acid – L-Arginine – is fundamental precursor of Nitric Oxide (NO).
NO is responsible for signalling the smooth muscle along the walls of blood vessels to relax and widen, allowing greater blood flow.
The natural conclusion was that more L-Arginine would further increase NO levels, and the Arginine based supplements were manufactured in bulk.
To an extent, they were right. Arginine does increase NO levels. The problem is that lots of it is broken down by the liver before it can be absorbed and start getting to work.
Another issue with nitric oxide boosting is that nitric oxide itself doesn’t stick around very long. This is fine in one sense, if your workout isn’t too long, but as mentioned earlier there are benefits to having the pump effect last as long as possible. Even after you stop lifting weights, more blood, nutrients and oxygen to the muscles are very beneficial.
Did You Know?The cellular expansion that takes place during muscle pumping workouts are one of the main triggers for hypertrophic muscle growth to begin.
The other trigger is the mechanical tension of lifting weights.
Citrulline – Better than Arginine
L-Citrulline, which we’ll just call citrulline, has been found during scientific research and clinical trials to be absorbed more readily than arginine.
That means it can essentially beat the liver and get into the blood stream.
Citrulline is itself a pre-cursor to arginine, which has already been established as a key agent in the synthesis of nitric oxide.
Arginine’s problem was that it gets broken down and rendered useless. With citrulline, there is no such problem.
In short: Citrulline increases active arginine levels in the bloodstream more than straight arginine can!
This sweet irony led researchers to say that citrulline is a more viable NO booster, and therefore muscle pump supplement, than arginine.
Dosage
Dosage is important where any supplement is concerned. Citrulline is no different.
It has been shown that 4000mg to 8000mg (4 to 8 grams) in an oral dose is excellent for inducing quality muscle pumps.
Now we’re in pre-workout shake territory.
Want the best muscle pump pre-workout in the game? – look no further than 4Gauge (read the review here).
Are There Other Ingredients Too?
Now that we’re on a roll, why not see if there are some other excellent ingredients out there for getting us swole??!!
Beet Root
Beets are a natural and delicious source of nitrates.
From the research on Citrulline, we know that it also increases nitrate and nitrite levels – and they are substrates of nitric oxide synthesis themselves.
The nitrates in beets are the building blocks of NO.
A perfect vasodilator made by nature.
Glutathione
We have talked about citrulline studies. A couple of them have been done in conjunction with a tripeptide (3 amino acids joined together) called as glutathione.
When consumed alongside citrulline, the NO boost was at its greatest and longest lasting effect.
This is because there are different points along the NO signal chain that are being triggered rather than the ultimately limited stage involving arginine alone.
Supplements Containing These Ingredients

If we could conclude anything from the above information, it would be more of a recommendation to look for these ingredients in your next pre-workout supplement.
Muscle pumps are not just for looking great in the mirror while you flex your body. They are legitimate and potently powerful effects for muscle growth and strength increases.
We use a product that is second to none in our opinion, and the opinions of many of our peers.
It contains these ingredients and some others on top, all of which are super well dosed and perfect for a pre-workout that gets you dialled in mentally and jacked up physically.
4Gauge is the name.
SWOLE…is the game!
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