Thread: Patrick's Arnold's Take on D-Aspartic Acid

Patrick's Arnold's Take on D-Aspartic Acid
by Patrick Arnold

You may have read about D-aspartic acid here recently in MD, or you may have heard of it somewhere else. If not, let me just give you a quick review of it. D-aspartic acid is the enantiomer of the dietary amino acid l-aspartic acid. Essentially this means it is the mirror image of L-aspartic acid. D-aspartic acid occurs naturally in the bodies of animals and is made by the action of the enzyme D-aspartic racemase upon dietary L-aspartic acid. D-aspartic acid is known to concentrate most specifically in neuroendocrine tissues such as the pituitary gland, pineal gland, and testes.

Recent research has shown the D-aspartic acid serves as a specialized neurotransmitter in parts of the nervous system involved in hormone production. It has been shown to stimulate the release of LH and GH from the pituitary gland. Furthermore, it has also been demonstrated to have a direct stimulating effect in the testes upon testosterone production.

I have been studying D-aspartic acid for about 10 years, and long ago theorized that it had the potential to raise testosterone levels in humans. I also in recent years have been experimenting with the product on athletes (more on that below). Within that time period, I submitted a patent application for its use in humans as a testosterone elevator.

Nothing had ever been publically published demonstrating that oral administration of D-aspartic acid can increase testosterone production in humans— that is until October 27th of last year. At that time, a study was published (Reproductive Biology and Endocrinology 2009, 7:120) in Italy, clearly demonstrating that oral administration of D-aspartic acid increases testosterone in humans, lending credence to the claim of my patent application.

The Italian study showed that doses of approximately 3 grams a day resulted in a rise of testosterone that peaked on day 12 (the last day of the study), at a level 42 percent greater than day zero. LH levels were also increased significantly. The study used 23 men, with all but three of them showing significant increases in testosterone. Furthermore, the levels of testosterone were still significantly increased three days after discontinuation of the D-aspartic acid. The data in the study strongly indicates that the amino acid builds up in target tissues over time, and then slowly decreases after administration is ceased.

As I said before, for a few years before this study was published, I had been experimenting on athletes (as well as upon myself) with this amino acid. However, there were some differences between the way I was using the product and the way it was used in the Italian article.

First off, my estimation of an active dosage was significantly higher. I based my doses on extrapolations from animal studies. What I mean by that is, I started with a dose that was used in a study that showed a demonstrable effect in hormone elevation in an animal. I then took that dose and did some rough calculations and estimations to arrive at what I believed would be an effective human dose.

For instance, in a study in sheep, a D-aspartic acid dose of 44.4 mg/kg bodyweight was used, and in a rat, study doses of 133 mg/kg bodyweight were used. These doses unfortunately were by injection (no animal studies using oral D-aspartic acid had been published at the time), so I had to make a guess as to what oral bioavailability might be relative to injection. Furthermore, I had to do calculations using something called the body surface area (BSA) normalization method to adjust for species differences in active doses between humans, sheep, and rats.

What I came to was a dose of 10 to 20 grams of D-aspartic acid a day. Now keep in mind that I am trying to determine a dose that has a reasonable chance of being effective— I am by no means trying to determine the minimally effective dosage, or the exact dosage for optimal results.

Another difference between my use of the amino acid and that of the Italians was that I did not use actual D-aspartic acid. At the time, D-aspartic acid simply wasn't available at an affordable price, so I used DL-aspartic acid. DL- is also known as racemic, which essentially is comprised of 50 percent D-isomer and 50 percent L-isomer. This form was much cheaper overall, and to arrive at the desired dose, I simply used twice as many grams as I would have for pure D-aspartic acid.

Now here is where the problem surfaced. You see, both D- and DL-aspartic acid are gritty, and sickly, sour-tasting powders. They will not dissolve in any liquids, and few athletes are willing to tolerate slugging down 20 to 40 grams of sour sand-like powder a day. Plus, even if they would get it down, chances are they're going to have some uncomfortable gastrointestinal problems.

So I did a fair amount of research and came up with a clever way of derivatizing the product. I found a way to make what is known as a calcium chelate of the amino acid. What that achieved, I was increasing the water solubility from less than 1 gram/200 milliliters to greater than 1 gram/5 milliliters. That's an increase in solubility of over 40 times, which is pretty remarkable. What is also remarkable about this chelate is that it happens to be stable over a very wide pH range. Once converted to the calcium chelate, the amino acid became much more user-friendly.

So at that point, I was able to get people to try it out on a more consistent basis. With the exception of some bodybuilders, most of the athletes taking the product were clean (drug-free) and the subjective feedback was very positive. Blood testosterone levels underwent significant elevations and recovery time was reduced for many users.

Today, D-aspartic acid is available at a relatively affordable price. And with the publishing of that Italian study, the cat is out of the bag, so to speak. So I have decided to release the calcium chelate product to the general public. It will be an apple-flavored liquid that contains 4.5 grams D-aspartic acid per ounce. Look for it; I expect it to be available in places such as the online MD store by the time this article hits the shelves.

That's it for this month, folks.

Addendum: I recently tested a sample of D-aspartic acid from China and found it to contain the much cheaper l-aspartic acid. I expect this to be an ongoing issue because the only way to differentiate between the two enantiomers is to determine something called optical rotation, using a piece of equipment known as a polarimeter. So if you're a company wanting to buy D-aspartic acid, make sure to get an independent analysis of a sample that features optical rotation data.

Interesting indeed.