Arginine, the mother of all nitric oxide products, is the most heavily advertised and controversial supplement in the industry.

What Arginine Does

Arginine is used in the synthesis of nitric oxide (NO). Among many of its effects in the body, fitness enthusiasts are primarily interested in NO for its purported vasodilating effects. In theory, arginine increases the production of NO, which in turn increases blood flow to the muscles. The increased blood flow brings more nutrients and oxygen to the muscle, and removes harmful byproducts resulting in an anabolic state that improves recovery and muscular hypertrophy.

What You Can Expect With Arginine

Although the research is muddy at best, manufacturers suggest you’ll experience more intense muscle pumps, more energy, and better recovery following strenuous workouts. One study has suggested a small improvement in strength following an 8 week course of 12 grams of arginine alpha-ketoglutarate daily.

When You Should Take Arginine

For its performance benefits, it’s best to take arginine 30-45 minutes before your workout. By taking it before your workout, you’ll increase the blood flow to your muscles during the critical post-workout period where muscle hypertrophy seems to be most easily influenced.

How Much You Should Take

Because the research is lacking, the dosing guidelines for arginine and its derivatives is far from definitive. Anywhere from 6g daily to up to 20g daily has been suggested. The easiest, although archaic, method to determine an appropriate dosage for an individual is to consume the largest amount, within reason, that doesn’t cause stomach upset and/or diarrhea.

The Downside

Side effects are somewhat common, especially when arginine is consumed in high doses. GI upset and diarrhea are the most common side effects.

TJ’s Inside Scoop

The large majority of research suggests arginine is poorly absorbed orally. The research that has shown positive benefits of supplementation with arginine has been via the intravenous route. Thus, l-citrulline, a precursor to arginine, may be a better option. In fact, it’s been shown to increase plasma arginine concentrations more so than oral arginine supplementation. Glycine propionyl-l-carnitine may also be a better alternative. At the very least, you should consume a nitric oxide product that contains various NO increasing ingredients.

What Does Arginine Stack Best With?

Whey Protein, Dextrose, Creatine, Beta Alanine, Amino Acids

Top Products Using Arginine

BSN NO-Xplode, Gaspari SuperPump Max, USPLabs Jack3d, MusclePharm Assault