D-Aspartic Acid is a relatively new addition to many athletes and bodybuilders stable of nutritional supplements. This is with good reason; since as far as all-natural, non-hormonal or pharmaceutical supplements go, D-Asp is the undisputed champion in boosting free and serum testosterone, and it’s clinically proven too.

D-Aspartic Acid is one of two forms of the amino acid Aspartic Acid. Its counterpart is L-Aspartic Acid (L = L isomer, D = D isomer), which is available in foods and plays a much more ubiquitous role in overall body functions; but does not affect testosterone as the D version does. D-Aspartic Acid, contrarily, is not available via foods directly, only through DL-Aspartic Acid, or a blend of the two. Only supplementation of D-Aspartic Acid, however, can deliver the amounts needed to show the remarkable testosterone increases demonstrated in clinicals.

Now to the important part, D-Asp has been shown to act synergistically on both neurological and testicular functions to up-regulate a whole slew of performance-related hormones. This is achieved by a chain reaction of several processes in the body, ultimately resulting in an increase in Luteinizing Hormone (LH) and testosterone. Just how much you ask? With a dose just over 3,000 mg per day, D-Asp produced astonishing increases in free and serum testosterone of over 40% in less than two weeks.

To put this in perspective, the world’s most popular all-natural “test-booster” Tribulus Terrestris has been touted since the 1970’s to boost testosterone levels naturally and produce all of the benefits that come from higher test levels. Tribulus, however, has consistently failed to demonstrate increased testosterone levels in multiple controlled studies. In other words, it has been shown to not increase free or serum testosterone levels. This is not a knock on Tribulus, as Tribulus clearly has huge benefits. It has been clinically shown to increase libido, sperm count, and has demonstrated many other related benefits that would point to an increase in testosterone. However, the mechanism of action of Tribulus is most likely an up-regulation of androgen receptors in the body; which is very hard to measure or quantify. This essentially means that Tribulus allows your body to use its existing testosterone much more thoroughly and efficiently which would also result in the favorable results. An interesting study would be the effects of D-Asp and Tribulus together in healthy male adults. While no study has been conducted as of yet on the two together, the synergistic use of both D-Asp and Tribulus are odds-on favorites to show some massive results in improved human performance.

When looking for a D-Asp supplement, look for one that is in free-form and thus easily absorbed by the body; AllMax Nutrition has just released an ultra pure free-form version (pictured). Dosage is just over 3 grams per day (3.12 to be exact) and many recommend taking it first thing in morning to ensure delivery. D-Asp is one of the few sports supplements that comes with clinical proof of results and would be a good addition to any male athletes supplement regimen. It is natural, safe and effective as well.