Nitrosigine
Nitrosigine is a patented form of arginine bonded to silicate. At 1,500 mg, blood arginine rises measurably. The research covers safety, absorption and cognitive tests. An effect on pump or blood flow during training was not measured in that research.
What the research shows
Mixed or small evidence. The effect is uncertain.
There are three human studies and all three measure an intermediate step. Kalman (2015) followed ten men and showed that 1500 mg raises blood arginine and salivary nitrite, without measuring performance or blood flow. Kalman (2016) measures a cognitive outcome with the Trail Making Test and was paid for by Nutrition 21, the owner of the Nitrosigine brand. Rogers (2020) is the only one that looks at blood flow: in 24 active young adults 1500 mg improved flow-mediated dilation more than placebo, as strongly as 8 grams of citrulline malate. That study came from Arkansas state research funds, with Nutrition 21 covering the publication costs only. No study measures strength, repetitions or muscle growth.
Who it makes sense for: People choosing a pre-workout that supplies 1500 mg, the dose that was studied, and accepting that the evidence stops at vasodilation measured on an ultrasound. Anyone aiming for more strength or muscle growth has no research to lean on here.
How we weigh evidenceClinical dosage
Origin
SyntheticNitrosigine (inositol-stabilized arginine silicate) is a patented ingredient by Nutrition21. It's a synthetic complex of arginine, silicate, and inositol designed to make arginine more stable and bioavailable than regular L-arginine.
Safety
Nitrosigine has been clinically studied and found safe at 1,500 mg per day. No significant side effects reported. Note the scale: the safety study had ten participants, all healthy men. The cognitive study was funded by manufacturer Nutrition 21, which employs two of the authors.
For comparison
No study compares Nitrosigine directly with citrulline or with regular arginine. What was measured: 1,500 mg raises blood arginine, and silicon stays elevated for about an hour and a half. Claims about how many grams of citrulline this equals come from the manufacturer.
Dosage by weight and gender
The studied dose is 1,500 mg per day. Both studies used that fixed dose, so nothing is known about dosing per kilo of body weight. Research has only been done in men. The effect on blood levels starts after a single dose and builds with daily use over 14 days.
Frequently asked questions
What is Nitrosigine?
Nitrosigine is a patented form of arginine, bonded to silicate and stabilized with inositol. At 1,500 mg, blood arginine rises measurably. Nitric oxide was not significantly higher after a first dose; after two weeks of daily use the baseline was higher. Blood flow itself was not measured in the research.
Is Nitrosigine better than citrulline?
That has not been studied. No trial compares the two head to head, so anyone claiming one beats the other is going beyond the data. Citrulline has a longer research history and costs less. Many pre-workouts contain both.
How much Nitrosigine per day?
The studied dose is 1,500 mg per day, ideally about half an hour before training. Both available studies used this dose. Whether more or less works better has not been studied.
Scientific sources
The clinical dosages on this page are based on peer-reviewed research.
- Acute effects of Nitrosigine® and citrulline malate on vasodilation in young adultsRogers JM et al. (2020)Funded by: Onderzoeksfondsen van de staat Arkansas en de University of Arkansas Honors College. Nutrition 21 betaalde met een onvoorwaardelijke bijdrage alleen de publicatiekosten en was verder niet bij de studie betrokken.
- A clinical evaluation to determine the safety, pharmacokinetics, and pharmacodynamics of an inositol-stabilized arginine silicate dietary supplement in healthy adult malesKalman DS et al. (2015)
- Randomized Prospective Double-Blind Studies to Evaluate the Cognitive Effects of Inositol-Stabilized Arginine Silicate in Healthy Physically Active AdultsKalman D et al. (2016)Funded by: Nutrition 21, eigenaar van het merk Nitrosigine, financierde de studie. Twee van de vier auteurs zijn er in dienst.
Pre-workouts with Nitrosigine
MuscleTech VaporX5 Next Gen
Pre-workout from MuscleTech with a nine gram scoop and thirty servings in a 266 gram tub. At two scoops the label lists three grams of creatine monohydrate, 3.2 grams of beta-alanine, 2.5 grams of betaine and 1.5 grams of Nitrosigine, plus caffeine. MuscleTech itself says to start at half a dose.
We keep the dosages and values on this page as accurate as possible based on selected studies. New research may change these values. Nothing on this page is medical advice. If you have any doubts, always consult a doctor.