Nitric Oxide Boosting Ingredients – Vasodilators

This article looks at a few of the most used nitric-oxide (NO) boosters on the market today.

  1. Nitrosigine – new trademarked type of Arginine Silicate. 
  2. Arginine AKG
  3. Citrulline Malate
  4. Norvaline
  5. Agmatine Sulphate
  6. Niacin (flush-form)

Nitric Oxide boosters – or Vasodilators, as they are also known – are becoming more and more prevalent within the supplement industry. Not only are these ingredients regarded as pre-workout favourites now but they are even making their way into post-workout supplements for the purpose of aiding recovery.

The ‘Pump’ effect is often synonymous with Nitric-Oxide boosters, as they enhance the naturally engorged and enlarged appearance of the working muscles during a session involving resistance weight training.

As the muscles contract during a set of several repetitions, they squeeze some the blood vessels which would normally transport the blood away, thereby trapping some in the muscle. The arteries continue to bring blood to the muscle, effectively filling the fluid spaces between the cells and muscle fibres with plasma. After the set is finished, this pressure build up releases – a lot like taking a tourniquet off – and blood rushes into the muscle.

That physical appearance of swollen muscles post-set is ‘The Pump’.

Gettin’ Pumped

Make sure you head over to our articles:

1. Nitric Oxide Boosting – The Pump
2. Getting Pumped and Staying Swole


If blood getting to the working muscle is key for the transportation of oxygen and nutrients then surely bigger transport vessels would be an advantage. It’s true that widening the blood vessels helps the working muscles push harder and go for longer. Supplement companies know this, vasodilation-inducing products were born.


The main mechanism to result in a massive ‘pump’ is vasodilation but the trigger is usually an increase in Nitric-Oxide. This compound sets of a chain of effects which ultimately leads to the relaxation of smooth muscle tissue which runs along the blood vessels. This relaxing effect allows the blood vessels to widen – i.e. dilate.

NO Boosting Ingredients

The following ingredients in some way elevate the user’s levels of nitric-oxide, thereby causing a vasodilation effect.


This is a newly patented form of arginine-silicate. Arginine is the main pre-cursor for nitric-oxide in the body and has probably been used as the industry leading vasodilator for the longest.

Nitrosigine claims to be the better compound arginine form bonded with silicon. Silicon has been demonstrated to be necessary for arterial wall strength and flexibility, which can further increase blood flow. According to the clinical study, Nitrosigine’s effects can start within 30 minutes of taking it and continue for 3 hours after. This is similar to most NO pre-cursors though.

Supplements containing Nitrosigine will likely be expensive for quite a while until it becomes more widely used. Initial market spread looks good with a lot of pre-workouts adapting their blends to accommodate it.

Study 1:

Arginine Silicate Supplementation Decreases Markers of Cardiovascular, Renal and Metabolic Dysfunction and Increases Markers of Vasodilation and Cardiovascular Health in Healthy Adult Males Komorowski, Rood-Ojalvo, El-Sohemy

Study 2:

A clinical evaluation to determine the safety, pharmacokinetics and pharmacodynamics of an inositol-stabilized arginine silicate dietary supplement in healthy adult males. (LB418) Kalman, Feldman, Samson, Krieger

Arginine Alpha-Ketoglutarate (AAKG)

This form of Arginine, bonded with alpha-ketoglutarate (a glutamine pre-cursor) appears to be a more effective variant than straight-up arginine. More research is needed to determine the true effectiveness as many scientific studies don’t seem to back up what a lot of people using it say, which is that it works. It’s only one of countless conflicts within the supplement industry.

However, there was one study involving 6g of arginine with 6g of AKG for a total of 12g. That’s a little on the weighty side of things if you consider this ingredient often shows up in supplements in quantities less than a single gram. Another study combined Creatine with A-AKG and yielded positive results also. There’s some good signs there but the studies on A-AKG may not take off if other newer NO boosters jump on the bandwagon.

12g Study:

Pharmacokinetics, safety, and effects on exercise performance of L-arginine alpha-ketoglutarate in trained adult men Campbell et al

w/Creatine Study:

Creatine, arginine alpha-ketoglutarate, amino acids, and medium-chain triglycerides and endurance and performance Little et al

Citrulline Malate

This is a pre-cursor to Arginine, but what you will often hear is that it is better at boosting NO than arginine, and the science backs it up. Clinical trials have looked for upper body and lower body muscle group exercise improvement with CM supplementation and they found it.

They used 8g of Citrulline Malate in the lower-body exercise trial, but again, most supplement manufacturers will never include this amount because of the cost to them. The most we’ve ever seen is in a pre-workout made by Jim Stoppani’s company. it’s called Pre-JYM and contains 6g of CM.

Upper Body Study

Effects of Supplemental Citrulline-Malate Ingestion on Blood Lactate, Cardiovascular Dynamics, and Resistance Exercise Performance in Trained Males Wax et al

Lower Body Study

Effects of supplemental citrulline malate ingestion during repeated bouts of lower-body exercise in advanced weightlifters Wax et al


This a non-essential amino-acid that seems to bring ‘the pump’ by inhibiting the inhibitor. Basically, the enzyme arginase which is responsible for wasting arginine can be blocked by L-Norvaline. The oddity here is that it seems only very beneficial to those people with conditions that cause a higher than desired ratio of arginase to arginine. In healthy people with ordinary arginine production etc. the NO levels are not greatly affected.

There is even a case for saying that large supplemental doses of L-Norvaline might be detrimental. After all, arginase has its purpose, one of which is purging the waste products of the nitrogen cycle from cells. Inhibit it and it might not go so well. The likelihood of a supplement containing large doses is not high though.

Inhibition of S6K1 accounts partially for the anti-inflammatory effects of the arginase inhibitor L-norvaline Xiu-Fen Ming et al

Agmatine Sulfate (Sulphate): Agmatine is a metabolite of Arginine, which is to say it modulates nitric oxide production even after Arginine has been broken down to its constituent parts. Agmatine has many claims behind it including: anti-inflammatory, anti-oxidant, nootropic, pain relief, insulin and kidney function. It’s up to you how enthusiastically you accept any one of these promises.

A promising area is Agmatine’s novel behaviour as a neurotransmitter, which might support more powerful muscle contractions and dial in your mind-muscle connection during a beastie workout. There’s even a suggestion that it can boost your Testosterone but we’ll need a few more studies on something with two legs and clothes, because let’s be honest, rats get their leg up on a light breeze.

The supplement companies are putting it in pre-workouts to help you get pumped up. You might find something around 500mg works for you.

Niacin (Flush Form)

Niacin is Vitamin B3. Big cheese, right! However, the flush form of Niacin might just be a potent vasodilator. Its name comes from the flushing or reddening of the skin from the vasodilatory effect and thus the increased blood flow.

The medical world seems hell-bent on reducing the flushing effect because patients who are using the vitamin to prevent cardio-vascular problems don’t like the side-effect. Bodybuilders, however, want it.

The mechanism and mitigation of niacin-induced flushing V S Kamanna et al


NItric Oxide boosters are mainly found in pre-workouts, although the value of them in the post-workout time frame is starting to be given credence. The transportation of nutrients and oxygen to the parts of the body that need them is not only important during a workout. Indeed, as long as you are providing the fuel then vasodilation is rarely a bad thing. And, recovery and growth is why we do this to ourselves in the first place.

Further Reading

Check out our article all about Nitric Oxide boosting 

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