Testosterone is the main anabolic hormone in the bodies of men and women, responsible for muscle growth (and more).
Everyone who engages in bodybuilding with the goal of increasing muscle mass is well acquainted with the properties of testosterone and therefore tries to manipulate its levels in the blood in various ways to promote faster muscle growth.
Main thoughts:
D-aspartic acid positively affects potency, increasing semen volume and sperm motility
One of the well-known and popular methods in professional and amateur bodybuilding for increasing testosterone is the use of anabolic steroids.
Steroids are synthetic analogs of testosterone. Their difference from testosterone is that their molecular structure has been chemically altered to enhance desired properties (anabolic, responsible for muscle mass gain) and eliminate unwanted ones (androgenic, such as hair growth, deepening of the voice, unpleasant body odor).
We recommend: Anabolic steroids for muscle mass gain: what they are and how they work
The practice of using steroids is unsafe for health, as it increases the risk of numerous side effects.
The second popular way to increase testosterone levels in the system is testosterone boosters or products/supplements that stimulate the natural production of this hormone when consumed.
The list of popular testosterone boosters includes about 15 products and supplements. In the material the 8 best testosterone-boosting supplements and 7 natural testosterone booster products, we discussed them.
In this article, we will talk in more detail about D-aspartic acid, which is among the popular testosterone boosters in sports and medicine. We will look at how effective it is for stimulating muscle growth in bodybuilding, as well as for treating sexual problems in men and women.
Recommended: Tribulus Terrestris is useless as a testosterone booster. Scientists’ reviews
What is D-aspartic acid?
Aspartic acid or asparagine is one of the 22 amino acids that our body uses for a large number of functions: building muscle mass, skin cells, nails, hair, creating hormones, enzymes, etc.
Amino acids are the structural units that make up protein. During digestion, the protein molecule is broken down into amino acids, which enter the bloodstream and are transported to strategic points to carry out their important mission.
There are two forms of D-aspartic acid: with the prefixes L- and D-. Their functions differ.
For example, L-aspartic acid is involved in protein synthesis, while D-aspartic acid is used to create certain hormones, including testosterone 2,3.
Based on this property of D-aspartic acid, its marketing as a testosterone booster in bodybuilding and medicine is built.
D-aspartic acid stimulates the production of certain hormones, including testosterone, which is the basis for its use in testosterone boosters
Recommended: Energy drinks for athletes: effects on the body and RISKS | Scientific facts
Scientific research on the effectiveness of D-aspartic acid as a testosterone booster
They are, as always, controversial.
In one study involving 23 healthy men aged 27 to 37 years, who took D-aspartic acid for 12 days, an increase in testosterone levels by 42% (!) was shown 4.
After stopping the intake, testosterone remained elevated by 22% on the third day.
In another experiment involving overweight men, the results were mixed: after 28 days of taking D-aspartic acid, the testosterone levels of some men did not change. It increased in those whose levels were below normal at the start of the study (on average by 20%) 5.
With prolonged intake over 90 days, a 30-60% increase in testosterone levels was demonstrated in men aged 27-43 with sexual problems 6.
Well, that’s not bad.
However, there is one “but”: in all three experiments, the subjects were NOT athletes.
What about athletes?
We recommend: Are anabolic steroids effective for weight loss and body drying?
The lack of effect on testosterone production in athletes is confirmed by an experiment involving young men engaged in bodybuilding who took D-aspartic acid at a dose of 3 g for 28 days 7.
Scientists suggested that perhaps a higher dosage is required for athletes. In another experiment, which also involved young bodybuilders, the dose of D-aspartic acid was increased to 6 g.
Result: the testosterone levels in the blood of athletes significantly decreased 8.
It was also confirmed that there was no effect on testosterone levels at a dose of 3 g in trained athletes.
Long-term intake of D-aspartic acid for 3 months also has no effect on testosterone levels 9.
D-aspartic acid does not seem to act as a testosterone booster for athletes.
This is likely explained by the fact that athletes have testosterone levels above normal, as physical exercise is a natural factor for its increase.
Scientific studies on the effectiveness of D-aspartic acid as a testosterone booster in women are not conducted, as the mechanism of action of this testosterone booster involves the testes, which, of course, are absent in women.
Scientific studies on the effectiveness of D-aspartic acid as a testosterone booster are contradictory: it seems to positively affect testosterone levels only in UNtrained men and is useless when taken by athletes in bodybuilding. This testosterone booster does not act on women by definition.
How effective is D-aspartic acid in bodybuilding for gaining muscle mass and increasing muscle strength?
Based on the data from the previous section, we get the following picture.
D-aspartic acid is taken in bodybuilding for a more active gain in muscle mass, as it is believed to stimulate the production of the anabolic hormone testosterone. However, scientific data indicates that in sports and bodybuilding, D-aspartic acid does not raise testosterone levels…
The logical conclusion is that since testosterone does not change, it is naive to expect any effect on muscle mass and strength from taking D-aspartic acid.
This is also confirmed by scientists.
In the two experiments mentioned above involving bodybuilder athletes taking D-aspartic acid as a testosterone booster and those who took a “placebo,” there was the same increase in muscle mass and strength 7,8.
It seems that D-aspartic acid is USELESS as a testosterone booster for stimulating muscle mass gain and increasing muscle strength in bodybuilding
We recommend: How to gain muscle mass? A guide for beginners
The effect of D-aspartic acid on sexual function
It is also true that in cases where the natural production of testosterone levels increases under the influence of D-aspartic acid (NOT in athletic men or those with low testosterone), its intake should have a positive effect on potency, i.e., increase libido (sexual desire), semen volume, and be beneficial for treating other symptoms of low testosterone.
This is supported by scientific research.
In one study, after taking D-aspartic acid for three months, 60 men showed that their semen volume increased significantly, sperm became more active, and 27% of their partners became pregnant during the experiment 6.
D-aspartic acid positively affects potency by increasing semen volume and sperm activity
We recommend: What is Glutamine needed for in bodybuilding?
How to take D-aspartic acid. Recommended dosage
In the aforementioned scientific studies, a dosage of D-aspartic acid ranging from 3 g to 6 g was used.
As shown, there is no clear dependence between dosage and effect: the result depends on the physical activity of men and their initial testosterone levels. Moreover, at higher doses (6 g) and prolonged use, there may be an effect of suppressing the natural production of testosterone in athletes…
It is likely that we will not be far off if we make the following conclusion: in sports and bodybuilding, d-aspartic acid as a testosterone booster is useless in any doses, but physically inactive men and those with low testosterone or potency issues can be recommended a dose of ~3 g per day.
The instructions for the use of d-aspartic acid are as follows: in sports and bodybuilding – not recommended, as there is no effect; for physically inactive men with low testosterone and for treating potency issues ~3 g per day
We recommend: Whey protein hydrolysate in bodybuilding: scientists’ reviews, how effective it is for gaining mass, how to take it best
Health risks of d-aspartic acid and possible side effects
No need to worry.
A thorough blood analysis after taking d-aspartic acid for 90 days in one study showed no dangerous changes 6.
In some cases, there are mentions of irritability, headaches, and nervousness 7, but they do not exceed the norm and are equally observed in participants from the control group (who took a “placebo” instead of d-aspartic acid).
D-aspartic acid is considered safe for health, and serious side effects from its intake have not been registered
We recommend: The harm of casein. Sports casein – the worst protein
Conclusion
D-aspartic acid is known as a natural testosterone booster popular in bodybuilding for stimulating muscle growth and in medicine for treating symptoms of low testosterone in men.
Scientific studies confirm the presence of an effect only in physically inactive men and those with below-normal testosterone levels. For those engaged in bodybuilding and other sports, d-aspartic acid as a testosterone booster does not seem to work.
In medicine, d-aspartic acid may be useful for treating potency issues and other symptoms of low testosterone.
