Extreme Endurance

Extreme Endurance will be in your system and working within 48-72 hours. We can confirm this from 12+ years of clinical testing.

Extreme Endurance can be taken together with almost every other supplement but you do not need to take any product containing Beta Alanine when taking Extreme Endurance.

We also recommend that you do not take additional magnesium supplements and if you have a question on dosage please reach out to info@xendurance.com.

Most active people and those that train hard get an adequate amount of magnesium with the daily dose of Extreme Endurance.

You do not need to take Extreme Endurance with food.

Extreme Endurance was the very first US sports nutrition supplement certified and tested for banned substances by LGC; Informed Sport.

LGC is a world-renowned sports doping control and research laboratory, with over 50 years of expertise in anti-doping in sport. LGC has published over 300 scientific papers on methods for the detection of trace levels of substances that are prohibited in sport and has over 450 man-years of research into doping control.

LGC has been testing supplements and ingredients on behalf of reputable manufacturers and suppliers for over 15 years. It has tested tens of thousands of samples during this time and has also carried out a number of research studies to explore the prevalence of contamination with prohibited substances in products and ingredients.

LGC's research into supplements and contamination also includes several administration studies to investigate the levels of prohibited substances that could cause an athlete to fail a doping test. These have been published in peer-reviewed scientific journals. As a doping control laboratory, LGC works directly with sports authorities, national anti-doping organizations, and national governing bodies worldwide.

There are no NCAA approved supplement products. The NCAA does not approve supplements.


Since 2007, Xendurance has had thousands of NCAA student-athletes take Xendurance products and rely on the Informed Sport certification which is a global testing method for banned substances. To learn more please find the Informed Sport link.

Over the years we have found that some people have a very acidic diet and their diet may interfere with the dissolution of the product in the small intestine. On the other hand, one of our athletes drinks 12 cups of coffee per day and lives on Extreme Endurance with great results! Everyone is different but the few that have had issues cleared up the dissolution problem by limiting acidic drinks, red meat, and coffee when taking Extreme Endurance.

We now encourage people to take their caffeine within an hour prior to or after taking their tablets just as a precaution.

You don’t cycle with Extreme Endurance. You take it consistently, like a multivitamin; for training, performance, heart-lung function, and for better body pH and alkalinity.

The most important thing to remember when taking Extreme Endurance is to take it consistently like you would a multivitamin. You can split the morning and evening dosage to the time of the day that works best for you. Ex; If you take it at 6 am and 5 pm, we encourage you to try to take it around 6 am and 5 pm everyday. You can take it with or without food.

We encourage a parent to email info@xendurance.com and provide the sport and activity level of their child and their age, and weight. We can then provide better guidance for the parent as to the experience we have seen with athletes using the product under the age of 18. We do not recommend anyone under the age of 14 use Extreme Endurance.