If you’ve asked the question “does D-Aspartic acid work” for increasing testosterone, has it crossed your mind that there are a slew of other products for which the same question’s still being asked? For example, since the 1990s we’ve heard that Tribulus Terristrus increases testosterone by stimulating a greater release of luteinizing hormone. But if Tribulus ever convincingly jacked up ‘test levels’, why would anyone ever need to ask whether D-Aspartic Acid does? We’d already have our commonplace method for raising endogenous testosterone; why’d there be such demand for another one?
I’m not hinting that the question “does D-Aspartic Acid work” isn’t worthwhile. Nor am I implying that failure of a past bodybuilding product to live up to its claims is evidence of a current one doing the same. I’m just encouraging a healthy dose of willingness to eye these claims critically; we’ve been down this road before. The question “does D-Aspartic Acid work” for increasing testosterone is reminiscent of the same question posed about a handful of other products:
- Does Boron increase testosterone? (At one time this was claimed – with “lab tests” and all)
- Does Horny Goat Weed increase testosterone? (Just the name convinced me to try it)
- Does DHEA increase testosterone? (Maybe… a little… in women)
- Does Tongkat Ali increase testosterone? (Maybe… if you take enough that Indonesian weeds start sprouting from your ears)
- Does Anrostenedione increase testosterone? (Apparently not enough to have convinced Mark McGuire to use it instead of steroids)
Each of the products above was once touted as the latest testosterone boosting miracle. In the case of Tribulus, I think the claims were that it’d been shown in studies to boost testosterone an average of… oh… forty percent or so – about the same as is now being said about D-Aspartic Acid. Funny, it seems the forty percent number is what marketers behind the studies feel safe in claiming.
In analyzing the question “does D-Aspartic Acid work”, let’s first determine what a forty percent increase in testosterone means (assuming a user gets one). If a guy’s in his early twenties and averaging 1,000 mcg./dec or so of endogenous testosterone, he’d have quite a jump. The D-Aspartic Acid would obviously shoot his natural test levels into the fourteen-hundreds. This would likely be noticeable by way of increased libido and possibly, better muscle gains. Contrastingly, if an older guy is averaging 500 mcg/dec of endogenous testosterone, a 40% jump would not even give him a boost that covers half the distance between what he’s been averaging and what the younger guy averaged while using nothing. Of course, assuming the stuff’s effective and works for older guys, one couldn’t rule out that it’s cyclically cumulative in its effect.
But the double-blind test that’s being cited for D-Aspartic Acid’s effectiveness was done on guys mostly in their late twenties. Proponents are claiming this as significant; one would assume subjects in that age bracket are still close to their testosterone productive capacity already. Indeed, a boost of that magnitude would probably put them back at their 18-year-old levels (Personally, I’m not sure I’d want to go there).
‘Does D-Aspartic Acid Work?’ If so, what’s the mechanism?
D-Aspartic Acid purportedly works by stimulating greater release of luteinizing hormone. This is the intermediary hormone in the loop feedback system that’s responsible for the bulk of testosterone release in men. The pituitary acts as a sort of sensor/regulator in this feedback system by sending more luteinizing hormone (LH) to the testes when it senses levels are low. It cuts back on LH release when levels become adequate. Theoretically, if the leydig cells in the testes have unused capacity, an increase in LH should certainly jump-start more testosterone production.
Of course, D-Aspartic Acid “working” assumes two things: that it reliably increases LH and that the user has unused capacity in the testes that’s just waiting for the stimulatory effects of more LH. Obviously, if testosterone isn’t at its max output because of something other than un-potentiated LH release (such as partially incapacitated leydig cells) then something that works primarily by increasing LH isn’t going to do much for raising testosterone.
What is D-Aspartic Acid?
D-Aspartic Acid is an amino acid that occurs naturally in the human body and is present in certain foods. It’s one of two forms of aspartic acid – the other being the ‘L-form’, which is a non-essential proteinogenic amino acid. Non-essential means the body can metabolically produce the amino acid from other amino acids and/or enzymes. ‘Proteinogenic’ means it’s an amino acid used as one of the building blocks of protein. The D-form of aspartate is comprised of the same molecular formula as the L-form but has a different molecular structure.
D-Aspartic acid exists in relatively high concentrations within the neuroendocrine tissues of both animals and humans. Perhaps this is why some researchers in Italy decided to test whether supplemental doses of it could stimulate greater LH release and testosterone production.
‘Does D-Aspartic Acid Work?’ A controlled experiment
The study often cited as the definitive answer to the question “does DAA work” was done on 23 males by Italian researchers and subsequently published in the journal ‘Reproductive Biology and Endocrinology.’ The subjects ranged in age from 27 to 37 and were given a daily 3-gram dosage of DAA while compared with a control group of 20 men receiving a placebo. Within 12 days of beginning the protocol, the subjects receiving the DAA reportedly averaged a 33% rise in LH and a 42% increase in testosterone.
Personally, I have trouble taking such small studies seriously unless they’re one in a meta-study or at least backed up by a second independent experiment. The chance for biased input, however unconscious, is too great within a test likely financed by someone who… well… has a financial interest in the outcome. Nothing wrong with that interest being present – only with believing the inputs and outcomes could be unbiased.
Also, a question naturally arises for me. What’s the supplemental dosage of DAA as a percentage of the average amount that naturally resides in the human body? To my knowledge, this is never mentioned. How come it’s never asked? Wouldn’t the likely efficacy and relative safety of 3 daily grams of supplemental D-aspartic acid first need to be viewed from the standpoint of what 3 grams represent as a ratio of what the body already averages of this amino acid?
‘Does D-Aspartic Acid Work?’ My anecdotal feedback
Just so I could provide my experiential input, I gave DAA a one-month trial. I gave two seemingly reputable brands a try and used them at the recommended dosage of 3 grams per day. When that seemed ineffective, I upped the dosage to 3.75 grams-a-day for a couple weeks.
What were my results?
With meticulous record keeping, I noticed nothing that would suggest an increase in testosterone.
Now… for the record… I’ve got a good ten years in age over the oldest reported test subjects in the double-blind experiment. This might make my feedback completely irrelevant to a guy in his third decade who’s thinking of giving this stuff a try.
My prediction: DAA will likely go the way of its predecessors, deservingly moving off the shelf at the same rate as your average Tribulus product.
But I’d love to get some other opinions. If you’ve tried DAA and you’d like to leave your feedback (positive or negative), feel free to share your experience.