Nitric oxide (or NO) products are the newest craze to hit the supplement world, promising substantial gains in lean muscle mass and strength. They are supposed to be ingested once a day prior to lifting for an increase in focus, strength, endurance, and recovery. Although they have already been taken up by companies everywhere, the premises behind Nitric Oxide supplements and their bold claims are still up for debate.

What is Nitric Oxide?

Nitric Oxide is a free form gas that is produced naturally by the body and facilitates blood circulation and transmitting messages between cells. It can be found in a variety of natural foods, most notably in citrus based fruits, but this is also accompanied by fructose and other sugars that can blunt the response and negate many of the effects.

Increasing your body’s nitric oxide via outside supplements is supposed to improve circulation and ideally dilate the vessels to enhance blood flow to the muscles. The theory is that by increasing the blood flow to the muscles the transport of essential nutrients would also increase, allowing for faster and more efficient growth and recovery.

What do NO Supplements Actually Do?

Although a typical ingredient profile can contain anywhere from 10-30 different compounds, Nitric Oxide is in effect only composed of two ingredients- Caffeine and Arginine.

The primary effects of caffeine are no mystery, although the potential benefits of ingesting it pre workout are up for debate. Arginine on the other hand is an amino acid that is not naturally produced by the body and is derived from fruits and meats instead. Arginine helps to facilitate protein synthesis and is a vasodilator, meaning that it is designed to open the blood vessels to allow more oxygen through. Arginine has also been researched for it’s ability to assist with the body’s release of Growth Hormone (GH). This is a natural process that occurs in each person at certain intervals throughout the day- typically upon waking up, falling asleep, and post workout. Arginine is thus recommended to be taken at these intervals to adequately impact GH levels. (It is also seen as effective for lowering blood pressure and assisting with erectile problems, both of which can stem from poor blood flow).

The numerous other ingredients in most NO boosters are usually just fillers. They are either just fancy names for sugars and simple amino acids or when they actually contain products that stimulate muscle growth (like creatine or beta alanine), they are included in such trace amounts that the effect is negligible. The only real exception is with a couple of other amino acids (like Citrulline Malate and Glutamine) that actually facilitate the uptake of arginine, as much of it is often left unabsorbed by the body in it’s natural state.

Do They Work?

Well, lets examine the two ingredients. Caffeine is a vasoconstrictor whereas Arginine is a vasodilator. If nothing else, the names should tell you that there is a problem. This would seem to be contradictory, but some of the effects are noticeable despite this, and the pump that NO products deliver remains for a short while after the initial caffeine rush disappears.

But lets discuss the pump. This is the name that most weightlifters associate with success, and is in fact the cause of most of the hype surrounding NO boosters. When weight training, the tearing of the muscle signals a rush of blood to flow to the working muscle, causing it to swell and expand. This temporarily makes the muscles appear larger and more defined and is often taken as confirmation that a workout is successful. Unfortunately, there really is no concrete correlation between a pronounced pump and enhanced muscular development, other than both usually occur during successful training.

In addition, the majority of NO supplements are pumped full of Maltodextrin and High Fructose Corn Syrup to mask the taste of these amino acids and are adding tons of simple sugars that only pack more calories. If that isn’t enough, then consider this- the response of both Arginine and Caffeine are blunted by the presence of any insulin in the blood stream (any carbohydrates raise insulin levels, but especially simple carbs).

The Verdict

What this equates to is that while Nitric Oxide is not entirely useless, it does not live up to the steroid-like claims by any means. The caffeine provides an initial energy boost as well as an increase in focus and the arginine can prolong your workouts for a bit, but neither ingredient is a substitute for hard work and proper nutrition.

Take a Nitric Oxide booster about 30 minutes prior to lifting and on an empty stomach for best results. This may mean playing around with your pre workout meal to get the timing right.

The Best Options:

Your best bet is to buy the raw ingredients in bulk and make your own Nitric Oxide booster. Arginine can be found as L-Arginine, Arginine Ethyl Ester, or Arginine AlphaKetaGlutarate (AAKG). Each form represents a step up in the bioavailability, meaning more is actually processed by the body (but also a step up in price). Just add some caffeine powder and Citrulline Malate and you’re good to go, or experiment with creatine, beta alanine, or other amino acids to improve the results.

If this is too much work, there are still plenty of other options to choose from, ranging in price from $20 to $50 a tub. Just make sure to look for products that are sugar free, as artificial sweeteners like sucralose and aspartame have far less of an impact on insulin and allow much of the NO to be absorbed. They are also available in pill form, though this is usually more expensive. The best premixed NO sources I have found are White Flood and Jacked, neither of which have too steep a price tag.