Triple-Action Nitric Oxide Boost with L-Arginine, L-Citrulline and Spectra*

Blood vessel cells naturally contain enzymes that produce nitric oxide, an important signaling molecule for maintaining blood vessel tone. Fitness Labs Nitric Oxide Boost™ is designed to assist your body’s normal production of nitric oxide by supplying three dynamic support factors: L-Arginine, L-Citrulline and Spectra™.*

L-Arginine is a key nitric oxide precursor*

L-Arginine is a well known amino acid that has been a popular “pump” ingredient with bodybuilders and athletes for years. It is one of the main precursors in the body’s mechanism to produce nitric oxide.* (See Figure 1)

L-Citrulline boosts L-Arginine to support nitric oxide levels*

L-Citrulline is closely related to L-Arginine in structure, and it also plays a significant role in the body’s production of nitric oxide. L-Citrulline is able to inhibit arginase, an enzyme that breaks down L-Arginine before it reaches the blood. As a result, taking L-Citrulline with L-Arginine may help more of the ingested L-Arginine pass through your system and get into the bloodstream.* 

Typically L-Arginine is extensively broken down by an enzyme called arginase during its journey through the GI tract and liver before reaching the blood. L-Citrulline, on the other hand, bypasses the liver after it is absorbed in the GI tract. Scientists believe this is why it can boost blood L-Arginine concentrations as well as, if not better than L-Arginine alone.* This is why we doubled-up on the amount of L-Citrulline in Fitness Labs Nitric Oxide Boost™.

According to some researchers, using a combination of L-Arginine and L-Citrulline is even more effective than taking L-Arginine alone. L-Citrulline is able to suppress arginase, an enzyme that breaks down L-Arginine. As a result, taking L-Citrulline with L-Arginine may help more of the ingested L-Arginine pass through your digestive system and get into the bloodstream.*


Spectra™ fights free radicals and supports nitric oxide*

Spectra™ is a precise blend of 29 gluten-free, non-GE fruit, vegetable and herbal ingredients designed to support the body’s response to five different free radicals. It works on peroxyl radicals, hydroxyl radicals, peroxynitrite, superoxide anion and singlet oxygen.*

A recent double-blind, crossover, placebo-controlled human study evaluated the effects of 100 mg of Spectra™ taken with breakfast after an overnight fast. Spectra™ demonstrated significant antioxidant action in healthy adults against reactive oxygen species (ROS), a category of free radicals.* (See Figure 2)

This decrease in free radicals also resulted in increased bioavailable nitric oxide concentrations.* (See Figure 3)


Try it today and help support your body’s production of nitric oxide*

Fitness Labs Nitric Oxide Boost™ combines the amino acids L-Citrulline and L-Arginine to help support nitric oxide production. The third support factor comes from the same dose of Spectra™ used in a human clinical study to help fight five major free radicals and support circulating nitric oxide levels.*


Directions: Take 4 capsules with a large glass of water 1-2 times daily. Take before workouts or between meals.

Support heart, muscle and circulation support with Fitness Labs Nitric Oxide Boost™!*

Spectra™ is a trademark of VDF FutureCeuticals, Inc. Used under license.


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