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 many times we tell people they should not combine with any more magnesium or calcium. If you are taking any other product with magnesium or calcium, please contact info@xendurance if you are concerned about the amount you are taking.

You do not need to take Extreme Endurance with food.

Extreme Endurance was the very first US sports nutrition supplement certified drug free by LGC; Informed Choice and 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 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 10 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.

 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 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 and for better body pH and alkalinity.