With numerous studies backing up the health claims surrounding D-Aspartic Acid (DAA for short) I thought it was necessary to review this fascinating amino acid. Therefore, in this article, I’ll uncover what makes this such a popular ingredient among bodybuilders, sports professionals, and neuro-hackers.
But first, what is D-Aspartic Acid? D-Aspartic Acid is a non-essential amino acid responsible for hormone stimulation, enhanced learning, and better recovery. And just to give you an overview of its functions, DAA can increase stimulation in your neuroendocrine tissues which are linked to hormone release:
Neuroendocrine tissues: Neuroendocrine tissues/cells are cells that receive neuronal input (neurotransmitters released by nerve cells or neurosecretory cells) and, as a consequence of this input, release message molecules (hormones) to the blood. (I)
Main Roles of D-Aspartic Acid
As I’ve already mentioned, DAA’s main role is to increase the production of hormones within your body. Namely testosterone, and yes, also estrogen which is a key hormone for women’s health. Alongside the benefits of testosterone production, DAA can also increase sperm quality in men.
Not just that, D-Aspartic Acid also holds qualities as a nootropic to boost learning and memory capabilities. Yes, that’s right, D-Aspartic Acid has been shown to be an important element towards the formation of memory cells – which builds connections within the brain responsible for improved learning – increasing mental performance.
D-Aspartic Acid can be sourced from certain food groups such as poultry, beef, and fish to name a few. It can also be made within the body in small amounts, mainly in the brain located in neuroendocrine tissue. The neuroendocrine tissues are responsible for nerve signalling and the release, and the production of hormones throughout the body which send signals to the endocrine glands (glands responsible for testosterone production) which is exactly why it’s so popular as a testosterone enhancing supplement. (II, III, IV)
How D-Aspartic Acid Works?
DAA accumulates in neuroendocrine tissues such as the pituitary gland, pineal gland, and gonads (testes and ovaries). In these neuroendocrine tissues, DAA works as an excitatory compound to stimulate the release of hormones throughout the body.
This means DAA helps your neuroendocrine tissues to release hormones throughout your body. As you’d expect, when increases of DAA are found within the body, it also increases the releases even more hormones. The main increase that you’ll find in regards to hormones is that of testosterone and luteinizing hormone.
What Is D-Aspartic Acid Made From?
D-Aspartic Acid is one of the enantiomers (a molecule made up of two parts that mirrors the other). It’s made from the other amino acid ‘Aspartate‘ – Aspartic Acid‘ and ‘Aspartate‘ which are similar in their structure. As a result, Aspartate is the binding base of Aspartic Acid, where their connection only occurs depending on the pH of the solution available in the body.
Okay, with that cleared up, where do the D and L come from in this equation? When D and L are used, in reference to ingredients such as DAA, it’s basically highlighting the ways in which molecules bend to light. D-isomers bend light to the right and L-isomers bend light to the left.
Molecules with D and L like structures such as L-Carnitine, for example, are known as enantiomers. In this case, we have two enantiomers working together; the D-Aspartic-Acid and the L-Aspartate which are now called a ‘racemic‘ mixture.
A racemic mixture is two molecules of exactly equal parts in the left and right side of the molecule. Hence, why DAA and L-Aspartate work together seamlessly. In short, you cannot have one without the other.
Benefits of D-Aspartic Acid
DAA works in a number of ways. As we’ve previously discussed, DAA can improve your testosterone, which in turn increases your muscle mass and strength output. Improvements can also be noticed in your libido and cognitive abilities.
In this next section, I’ll discuss how DAA works throughout the body in each of these ways – highlighting the path in which it takes to make all of the benefits surrounding D-Aspartic Acid happen.
As more testosterone is directly linked to better physical performance, this is one measure of how D-Aspartic Acid may help to increase your sporting abilities and recovery.
A study found that supplementing with D-Aspartic Acid increased luteinizing hormone compared to a placebo group. The D-Aspartic Acid group saw their Luteinizing hormone LH levels increase by more than 30%. Not only that, but their testosterone levels also increased by more than 40% in comparison to the placebo group. (VI)
When taking into account the relationship between luteinizing hormone LH, and the responsibilities it holds for producing male characteristics, such as muscle growth and strength, then we could safely agree that D-Aspartic Acid is beneficial for improved strength, muscle building, and performance.
Increases Levels of Testosterone
As previously mentioned, DAA can improve testosterone levels by releasing luteinizing hormone, follicle-stimulating hormone, and growth hormone. It builds up the testicles, where it then alleviates a rate-limiting step of testosterone synthesis – this ultimately leads to an increase in testosterone production.
The link between DAA and increased testosterone is thought to come from the ability to stimulate the activity of the ‘rate-limiting step’ in steroidogenesis (steroid synthesis) found in the testes. (VII)
In plain English, this means that DAA increases activities in the testicles linked to enhanced testosterone production. This gives you many enhanced benefits, from more lean muscle mass and better recovery to name a few.
In men with low levels of testosterone, DAA has been shown to provide a significant increase in testosterone, along with improved sperm levels. (VIII) However, in athletes where testosterone levels were already above base-line, D-Aspartic-Acid shows no significant benefit. (IX)
This means, that those of you with existing high levels of ‘T’ may not notice a change. But those who are low in ‘T’ would on the other hand benefit greatly from using DAA.
Improved Sperm Quality
Sperm quality and sperm amount is another benefit surrounding the use of D-Aspartic Acid. D-Aspartic Acid seems to be linked to the spermatogenesis: which is the epicentre of sperm production within a man’s testicles. (X) Thanks to this link, studies suggest that it could play a role in the formation of sperm cells in the reproductive organs. (XI)
A study which took a group of men and gave them 2.66g of D-Aspartic Acid for 90 days with already low seminal profiles saw improvements after the 90 days. So much so, improvements in seminal motility (the ability for an organism to move independently), along with a stronger concentration from 50-100% improvements from baseline.
The study concluded that fertility rates significantly improved throughout all participants. Meaning, their testosterone and sperm quality went back to optimal levels. (XII)
NMDARs, or N-methyl-D-aspartates receptors for short, are thought to be critical in synaptic plasticity, which is a cellular mechanism for learning and memory. “The NMDA receptor is very important for controlling synaptic plasticity and memory function,” as it’s known as an excitatory element in the central nervous system. (XIII) What does this mean?
This means; N-methyl-D-aspartates (which is partly similar to that of D-Aspartic Acid) allows the body to stimulate chemicals responsible for cognition and improved learning. (XIV)
Study on DAA and enhanced learning:
A study carried out by the Laboratory of Animal Physiology and Evolution in Naples, Italy, found that rats with higher levels of D-Aspartic Acid were able to demonstrate faster problem-solving.
The rats were supplemented with sodium D-aspartate (40 mM) for 12-16 days, where marked improvements were found in “the rat’s cognitive capability to find a hidden platform in the Morris water maze system.” (XV)
This study concluded; the rats with higher levels of DAA were better equipped at problem-solving in the test, which involved a water maze. In humans, the amount to mirror these results would make roughly 2.53g per day of D-Aspartic Acid supplementation in most people. As most D-Aspartic Acid supplements contain 3g and higher, it’s safe to say you’re covered in this area.
In light of these animal studies, we can see it may have some benefit to cognition and memory. However, more research needs to be done to determine if these results carry over to humans.
Low Levels Of D-Aspartic Acid – What’s The Outcome?
A myriad of negative effects may be felt due to the lack of D-Aspartic Acid production within the body. Such as; muscle loss, a dip in performance, low libido, and confidence issues to name a few. Right now I’ll briefly outline how low levels of D-Aspartic Acid could affect your performance and other important areas of physical and mental health.
Benefits from an increase in D-Aspartic Acid can be linked to performance, increased muscle size and density, heightened sex drive, alertness, and also, (as an indirect positive) it may increase confidence in men who may be lacking in testosterone.
Why is this? Because testosterone is directly linked with self-confidence and levels of self-worth. If testosterone levels are low, then, so might your energy levels and libido, thus affecting your overall confidence.
Hormones are incredibly important where sports are concerned. Take combat sports as an example. A fighter who has low testosterone levels compared to his component might back away from a possible attack, or they may not have enough speed or confidence to strike. Subsequently, these actions (or lack thereof) could potentially see a fighter lose their fight.
This is just one scenario, but you can see that in any sport where confidence is not present (for whatever reason) could prove to be a disadvantage.
When the endocrine system is stimulated, a balanced release of chemical signals is released to stimulate hormone production. If for whatever reason, these signals aren’t being triggered, then it’s a possibility that your libido (sex drive) could fall victim.
Why would the endocrine system not receive signalling to trigger the creation of testosterone? When one hormone is being released, it’s virtually impossible for another to work at the same time. For example;
When cortisol (the stress hormone) is being released in the endocrine system, testosterone cannot be produced. So, if your stress levels are above normal for whatever reason, possibly emotional, or physical stress training – then you may fall into this category. Even more so, when cortisol is too high, it will delay your recovery process post exercise. Therefore, I suggest looking into the use of ashwagandha to combat this.
By now you should see a pattern emerging. As testosterone is directly linked to muscle growth – and without the right chemical signals to turn on testosterone production in the endocrine system, then, muscle loss will occur. Those of you who find muscle building a difficult task could be due to a lack of testosterone.
For an accurate reading, it’s advised to speak to a health care professional to have your testosterone levels checked – ideally between 7-10am as this is when your testosterone levels are at their highest.
D-Aspartic Acid Doses – How Much To Use?
You’ll find a variety of dosage recommendations in a number of supplements. From testosterone boosters to male health vitamins – all of which have their own take on how much DAA you should be using.
However, as a standard recommendation, you should aim for between 2,000 – 3,000mg per day. Stick with this as a guideline and you won’t go far wrong. (XVI)
D-Aspartic Acid is still in its infancy when it comes to human research. Therefore, more evidence needs to be collected as to whether or not DAA should be cycled on and off for safety and obtaining the best results. As always, consult your health care provider before starting any new supplement program.
Where Can You Find D-Aspartic Acid In Foods?
D-Aspartic can be found in sources such as soy protein, casein protein i.e. cottage cheese, animal meats, and corn protein to name a few. However, dairy is the most abundant source of DAA;
“Reports suggest that levels of DAA can be doubled via the pasteurization process of raw milk – increasing from 1.5% to 3% in total.” (XVII)
D-Aspartic Acid Side Effects
A study carried out by the Department of Clinical Chemistry in Italy, took participants and gave them 2,660mg per day for 90 days. Their electrolytes, glucose, urea, enzymes, creatinine, and blood cells were tested. The results? No abnormalities were found, thus highlighting D-Aspartic Acid safe to use over an extended period. (XVIII)
On the other hand, another study found that when participants took 6 grams a day for two weeks saw some negative effects. Their testosterone levels dropped slightly. However, the most famous study on D-Aspartic Acid, where the trial used 2,660mg per day, saw positive results in men with low levels of testosterone.
So, is D-Aspartic Acid safe or not? According to the research and the above-mentioned studies, if you supplement with the recommended daily dose of 2,660mg per day on average, then you should be fine, posing no adverse side effects. (XIX)
However, if you push the upper limit of dosages to 6 grams per day, then you may start to see a decline in positive results, cancelling out testosterone production for example. (XX)
Sport Nutrition Expert Recommendation?
While D-Aspartic Acid has been touted as an aid for men’s testosterone production, more research needs to be done to prove its full benefits for the human body where performance is concerned. But, if we link the close connection of testosterone and its ability to increase physical performance, it’s safe to assume it will improve your results.
Furthermore, if we analyze the overall results we can see that DAA looks to be a viable option for increasing hormone levels and also excitatory compounds for enhanced cognition – also improving mental performance and focus.
In summary, D-Aspartic Acid looks to be a good supplement to have in your health regime, thanks to the way it stimulates the neuroendocrine tissues. It’s these neuroendocrine tissues that are the key players responsible for the release of hormones throughout the body. Look for supplements containing roughly 2-3g per daily dosage, this way you know you’re on the right track.
(I, II) Wikipedia Neuroendocrine cell. (source)
(III) Wikipedia Aspartic acid. (source)
(IV) Wikipedia Genetic code. (source)
(V) Luteinizing Hormone (LH) Test: What It Is and Why It’s Important. (source)
(VI) The role and molecular mechanism of D-aspartic acid in the release and synthesis of LH and testosterone in humans and rats. (source)
(VII) The Rate‐Limiting Step of Adrenal Steroidogenesis and Adenosine 3′:5′‐Monophosphate. (source)
(VIII) Three and six grams supplementation of d-aspartic acid in resistance trained men. (source)
(IX) Stimulation of steroidogenic acute regulatory protein (StAR) gene expression by d-aspartate in rat Leydig cells. (source)
(X) Wikipedia Spermatogenesis. (source)
(XI) The occurrence of D-aspartic acid in human seminal plasma and spermatozoa: possible role in reproduction. (source)
(XII) D-Aspartate, a Key Element for the Improvement of Sperm Quality. (source)
(XIII, XIV) Memory and the NMDA Receptors. (source)
(XV) Evidence for the involvement of D-aspartic acid in learning and memory of rat.. (source)
(XVI, XVII) Summary of D-Aspartic Acid. (source)
(XVIII, XIX) D-Aspartate, a Key Element for the Improvement of Sperm Quality. (source)
(XX) Three and six grams supplementation of d-aspartic acid in resistance trained men. (source)