One of the the most popular bodybuilding supplement categories is Nitric Oxide boosters, or vasodilation enhancers to give it another name. Here we explain what NO booster are and what they do.

Putting it in simple terms, vasodilation is a process that relaxes the blood vessel walls to allow veins and arteries to attain a slightly larger diameter. This slight enlargement of the blood vessels allows the muscles to receive a larger volume of blood over the same time.
This can benefit bodybuilders and other athletes in two ways.
- By carrying away more of the chemical by-products produced by hard-worked muscles.
- By allowing an improved supply of oxygen and nutrients to the working muscles
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How Does Vasodilation Rid the Muscles of Unwanted Chemicals?
Whenever muscles are put under stress in the gym, on the track, or during sporting activities, certain chemicals are produced – most notably lactic acid and ammonia – which can hinder performance levels and slow recovery thereafter.
Lactic acid build-up, for instance, can manifest itself in the form of burning muscles, cramps, and nausea.
Such feelings are very hard to “work through”, but whenever the blood supply is increased by vasodilation the cardiovascular system is able to flush the muscles of unwanted chemicals more efficiently.
Needless to say this makes it easier to train harder and longer.
How Does Vasodilation Feed the Muscles?
As well as carrying away unwanted chemicals the cardiovascular system also ensures the muscles are well fed by providing them with all the nutrients and oxygen they require to function efficiently and heal (build up) as fast as possible.
Some nutrients provide the muscles with the energy required to help power their actions, others (protein for example) are required to repair damaged muscle fibres.
Oxygen is required for a process called cellular respiration that provides the muscles with ATP (a valuable energy source) and the harder the muscles are worked the more ATP they require.
What are NO Boosters?
“NO” stands for Nitric Oxide, and Nitric Oxide is essential for the vasodilation process. Bearing in mind all the benefits vasodilation can supply it is not surprising so many supplement manufacturers have developed formulations that aim to boost NO levels.
Increasing NO is one the quickest and best ways to help athletes get more from their workouts and maximize their results.
What are the Best NO Boosting Ingredients?
The list below is not by any means exhaustive, but it contains some of the most common NO boosting ingredients.
It also contains a few ingredients that are often blended in with NO boosters to help maximize the benefits they provide.
Nitrosigine (trademarked)
A branded ingredient produced by Nutrition 21. It contains a special blend of arginine and silicate that is proven to provide effective vasodilation without presenting any health risks.
The ingredient also offers other desirable benefits.
It can provide the muscles with arginine for up to three hours and, as arginine can boost protein synthesis; this is a valuable benefit indeed.
Nitrosigine also increases silicon absorption rates, thereby strengthening the arteries and other blood vessels, and the effect lasts for around 1 ½ hours.

Arginine AKG (Arginine Alpha-ketoglutarate)
A non-essential amino acid that possesses natural NO boosting abilities.
It can also help the liver to break-down the unwanted ammonia the blood has purged from the muscles, and has a good reputation for helping to minimize muscle pains and stiffness.
Not surprisingly these abilities make Arginine AKG a highly favoured ingredient with supplement manufacturers who are trying to create powerful NO boosting formulations.
Agmatine Sulphate
Although it is quite a new ingredient, agmatine sulphate has a good reputation for delivering results and is fast becoming an extremely popular NO booster.
There is also a growing belief that it is capable of stimulating production of human growth hormone (HGH).
Niacin
Also known as vitamin B3, Niacin offers numerous health benefits and is often used to boost the metabolism.
Like agmatine sulphate, it is sometimes deemed a HGH provider, so its natural abilities as an NO booster could, in many ways, be seen as the icing on the cake.
Citrulline Malate
UPDATE: Citrulline (Malate Di-Malate) is now considered the most effective and longest lasting vasodilator for getting swole/pumped during a weightlifting session. It is MUCH BETTER than arginine.
Citrulline Malate is a pre-cursor to arginine, the well known NO boosting amino acid.
The interesting thing is that it can increase plasma arginine over a longer period of time than a straight shot of arginine would.
Secondly Citrulline can help purge the body of lactic acid and ammonia.
Empirical evidence suggests this ingredient is a high caliber muscle endurance booster.
4GAUGE is the best Citrulline product. It contains a huge 6 grams of Citrulline Di-Malate and has 2 other vasodilating ingredients in its formula.
Basically, it completely blows us away every time we go to the gym. The shotgun shell packaging is appropriate!
Norvaline
Norvaline’s input to the nitric oxide chain is by way of its inhibitory action against the enzyme which itself inhibits arginine – arginase.
Basically, it keep more arginine in your circulation for longer.
It may also boost performance by ensuring the liver processes unwanted toxins in the quickest and most efficient manner possible.
Stacking-up the Benefits
Some formulations are better than others, but the best vasodilators on the market can help bodybuilders and other athletes take their training to the next level and meet/exceed their training goals.
Vasodilators are probably best seen as a means of improving delivery though, and are unlikely to provide all the nutrients the muscles require.
In general the necessary nutrients will need to be provided elsewhere, either from the diet or from other supplements, so it is not uncommon for athletes to stack vasodilators with protein powders or other nutrient-rich formulations.
As is always the case, however, some care is required when choosing the best supplements to combine, but a good NO booster/vasodilator and an effective bodybuilding supplement can be an extremely powerful combination
Recommended NO Booster

4 Gauge has to be one of the most interestingly packaged sports supplements on the market and customer feedback shows it delivers the kind of results the manufacturer promises. This is not surprising.
The ingredients used in the formulation are very good and there does not appear to have been any scrimping on the inclusion rates.
If you are looking for a pre-workout supplement that will ensure you go great guns in the gym, 4 Gauge is the one you need.