“Does the Glycemic Index Work for Weight Loss”… or is it a gimmick?
“Is Too Much Cardio Bad”; is it actually dangerous?

“Does D-Aspartic Acid Work”; Does it Increase Testosterone?

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.


Does D-Aspartic Acid Work_Does it Increase Testosterone 
‘Does D-Aspartic Acid Work’ in raising testosterone levels? One study says it does. But anecdotal feedback from users doesn’t seem commensurate with the study results.


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.



I used it for a couple of weeks and then had trouble keeping on the powder. I did notice some improvement and noticed my feet stunk like they did when I was a teenager. As soon as I stopped my foot stink stopped. I am inclined to think that it does work. I'm 40 years old


Hello, I am a natural bodybuilder still in my second decade of life, although in my fifth year of training. As progress slows, my patience thins, and my desire for a change in my own hormones increases. Of course a more natural, safer substitution for steroids is optimal, and as always, a solution too good to be true appears. I've done some significant research on DAA for this reason as well and I thank you for your input. Anecdotally: DAA gave me a complete placebo. It was sour and expensive and yielded nothing out of the ordinary. I tried it 3 times. Save your money for better performance enhancement drugs, this one belongs on a shelf at GNC.


This is the first time i am reading your post and admire that you posted article which gives users lot of information regarding particular
topic thanks for this share.

Scott Abbett

Hi Matt,

Thank you for stopping by and providing your thoughts.

I agree with you: What's the point of reporting these findings that fall within the natural variance of daily testosterone fluctuations? A 30% rise or drop in T-levels can occur just by eating the right or the wrong thing in a single day. What's the significance of this when guys who take T-replacement or 'roids are augmenting this hormone by a thousnd percent or more?

I have a question: Where are you getting the stat that says the DAA will be effective for a "handful of people?" I'm reminded of the annoyance I feel when reading bodybuilding message boards in which guys are debating the effectiveness of some useless supplement like Tribulus. They'll often say something like the following:

"Well... it works for some people... but everyone's different."

"Ugh"... this is mindless extrapolation that makes double-blind studies practically meaningless. That kind of small positive variance can easily be attributable to the placebo effect. Wouldn't you agree?


Realistically nobody under the age of say 37 should be even bothing with this product. A 30% boost in testosterone, although it sounds good does not equate in anyway to a 30% boost to performance. Most people with already natural levels of testosterone will simply continue to have natural levels of testosterone. 30% does sound significant, but illegal supplements actually boost test levels by 1000's of percent. The only good think about this product is that D-Aspartic Acid would appear the only natural test booster to have any effect at all on testosterone, just a very small one for a handful of people.


DAA definitely works. I have blood tests about every 2 months because I have been dealing with low test for some time and I am 37. I've seen a 60% increase running DAA solo and an additional 12% with a stinging nettle stack (divanil). It's certainly not a cycle or close to one, but when you are low, a 72% increase is amazing.


Hi Johnny P,

Interesting! Your annecdotal experience is lent more credibility by the fact that you're not back-linking to a supplements site.

When you get a chance, I'd love for you to tell readers what brand of DAA you're using, as well as the "other supplements" you've mentioned.

Thanks for commenting.


johnny p

My lifts and size have gone up dramatically in the three weeks I have been taking daa, my friend who is a chemist and has never let me down in the past assured me it works magic. I am taking a pre-workout suppliment and protein along with daa. Two thumbs up from myself and the chemist.

Aspartic Acid

This is really interesting take on the concept. I never thought of it that way. I came across this site recently which I think it will be a great use of new ideas and informations. Thanks a lot...


I have never tried any type of Tribulus supplement before, so I was browsing around and found Dr Max Powers Testosterone Booster. Taking just one capsule on an empty stomach morning and afternoon I seemed to feel much better all around on the 3rd to 4th day and forward. My workouts went better, I felt more like a "beast" while lifting, if that makes any sense. Recovery seemed to not be as painfully sore after lifting the next couple of days, especially when I pushed myself too far, so I'm going to chalk that one up to 'boosted' or 'leveled' test levels. All around, I don't have any negatives to report back, and for the price, you really can't complain.


im a 21 yr old guy starting this today. ill give you guys the results in a month


Hey Bali,

Your theory about muscle mass quantity being reflective of endogenous testosterone levels would be universally feasible if there were no such thing as steroids. Since steroids are an exogenous testosterone source and they're so prevalent in bodybuilding, it's difficult to even predict who'd be most muscular if they didn't exist. If such a drug-free hypothetical situation existed, it could probably safely be said that the most muscular guys (and gals) were the ones with the highest natural testosterone levels.

There was a really muscular middle-aged guy that used to work out at the gym where I train. This guy was physiologically hooked to steroids. He confessed to someone I knew (I heard this second-hand) that he'd been on steroids for so long that he knew if he'd come off them, he'd have no natural testosterone at all. Worse, he didn't believe he could ever get endogenous production back.

That's an extreme case of someone's muscularity not being reflective of his "real" testosterone levels.

Libido is definitely a good first-line indication of how testosterone levels are doing. And yes... overtraining can certainly knock your testosterone, muscle-growth, and "you-know-what" right into the dirt.

Cruciferous vegetables (like broccoli) are great for minimizing estrogen and, thus, maximizing endogenous testosterone levels. I think eating beef raises testosterone, but I have no solid evidence of it.

One of the best ways for a guy to make sure he has adequate testosterone is by shedding all (or not gaining any) abdominal fat. A good chunk of fat around the middle has been shown to cut natural testosterone levels in half.

As always, thank you for your comments Bali.

Hope your training's going well.



Hey Scott

Interesting post you have written here. Along with the numerous alleged muscle building supplement reviews you have here on this blog.

For me personally I don't think these test boosters work. I'd rather rely on beef and broccoli than a daily dose of 3 grams of powder.

But all this hype about test boosting products causes me to wonder: Does it stand to reason that an individual with more muscle mass on his frame has higher average testosterone levels than someone with less muscle? An illustration would be between lets say an intermediate bodybuilder and an advanced counterpart.

Also, is it reasonable to conclude that males with consistently higher libido and who demonstrate more "alpha male behavior" will have a relatively easier task in building mass and strength?

Bottom line, can a person's libido be a key factor in gauging his muscle building success? I know there are other numerous factors but this is definitely one that deserves some attention. In my own personal experience when in a prolonged period of overtraining my test levels must have taken a dip since libido plummeted.

If you've read up to here Scott I thank you for your attention.


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