d aspartic acid and testosterone diagram

D-aspartic acid study summary: DAA is my top recommended ingredient for any testosterone booster. Studies have shown that this amino acid is very effective in regulating and increase free testosterone levels.

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An amino acid known for enhancing the blood testosterone level, D-Aspartic acid contains properties that improve muscle strength, increases lean body mass and boosts energy levels. Naturally produced in the body, studies from animal and clinical trials have shown its high concentration in brains and testes. Although there has been no consensus on the exact molecular mechanism by which D-Aspartic acid increases testosterone levels, studies strongly suggest that this particular acid contains testosterone-boosting properties.

A more detailed summary of these studies, illustrating the effect of D-Aspartic acid in animals and humans, can be found below. Each study examines whether (and how) D-Aspartic acid leads to an increase in testosterone levels and analyzes the flow-on effects as a result.

Aspartic acid in treating male infertility.

Study: A supplement containing 80% D-Aspartic acid (1.6g) and 20% L-Aspartic acid (0.4g) was given to men between the ages of 25-40. The men were to take this supplement, daily, in half a glass of water or juice, after lunch for 20 consecutive days. Measurements were then taken on testosterone and luteinizing hormone levels, both of which are crucial to reproduction.

Results: The experiment found increases in testosterone and luteinizing hormone levels in 8 out of the 10 men. In addition, the number of motile sperms in these individuals increased by 51%

Conclusion: D-aspartic acid and L-aspartic acid can effectively increase the levels of testosterone when taken for 20 days at a dose of 2g/day.

Source : http://www.google.com/patents/US20120095100


Aspartic acid induces the release of testosterone and luteinizing hormones.

Study: A treatment study was conducted on 23 men enrolled in an infertility program. These men were given 3.2g of D-Aspartate for 12 days, and blood samples were collected for hormonal testing between treatments, as well as after. This experiment was simultaneously conducted on rats.

Results: The experiment saw a significant increase in levels of luteinizing and testosterone levels in 20 out of 23 men. These levels remained high after six days of treatment and did not decline for three days after the treatment ended. Amongst the rats, the levels of testosterone were found to be higher than the levels of luteinizing hormones.

Conclusion: A 12-day D-Aspartate treatment led to a significant increase in testosterone levels.

Source: http://www.ncbi.nlm.nih.gov/pubmed/19860889


D-aspartic acid plays a crucial role in initiating synthesis of testosterone in mallard birds.

Study: D-Aspartic Acid has been found to be effective amongst birds. A study conducted by the University of Naples reported findings on the role of this amino acid in testosterone production amongst mallard birds.

Results: The authors quantified the natural D-Aspartic acid levels in the testosterone producing cells (Leydig cells) and observed that high levels coincided with high levels of testosterone.

Conclusion: D-Aspartic acid has a positive role in initiation and production of testosterone amongst mallard birds.

Source: http://www.rbej.com/content/6/1/28


D-aspartic acid influences testosterone production amongst wild pigs (Boar).

Study: A study was conducted by Lamanna and co on wild pigs, a mammal with a high number of testosterone producing cells, otherwise known as Leydig cells. Using the highly sophisticated immunohistochemistry technique, the level of natural D-Aspartic acid and testosterone in these cells were quantified. This was done by culturing the cells in the laboratory.

Result: High levels of testosterone were found in tissues where there was an abundant level of D-Aspartic acid.

Conclusion: D-Aspartic acid induces the production of testosterone in wild pigs.

Source: http://www.ncbi.nlm.nih.gov/pubmed/16996125


D-Aspartic acid increases reproductive hormone secretions in green frog.

Study: During a study conducted on green frogs, F Raucci and co discovered that D-Aspartic acid levels increased during the reproductive phase, modulating the production of testosterone. The frogs were given D-Aspartic acid injections and subsequently quantified the levels of testosterone. An increase in testosterone levels was observed, although a decline was noted after 18 hours.

Result: Among frogs, D-Aspartic acid positively modulates the production of testosterone. Injecting D-Aspartic acid increases the level of this amino acid in testes, which was followed by an increase in testosterone levels.

Conclusion: D-Aspartic acid increases testosterone production levels amongst green frogs.

Source: http://joe.endocrinology-journals.org/content/182/2/365.long


 A molecular study on rats and the effects of D-Aspartate on their testosterone levels.

Study: Nagata and co administered rats with D-Aspartate to study its molecular targets. In particular, the genes/proteins that were up-regulated.

Results: This was the first report to show a molecular target that eventually led to an increase in testosterone levels. A protein called “StAR” is activated by D-Aspartic acid, leading to increased secretions of testosterone from Leydig cells (testosterone producing cells).

Conclusion: D-Aspartic acid induces the release of testosterone by activating the StAR protein.

Source: http://www.ncbi.nlm.nih.gov/pubmed/10050750


Increased testosterone production by laboratory cultured cells from rat testes.

Study: The Leydig cells (testosterone producing cells) from rat testis were cultured in petri dishes in the presence of D-Aspartic acid and other amino acids. The levels of D-Aspartic acid and testosterone in these cells were quantified.

Result: There was a significant increase in the levels of testosterone and D-Aspartic acid in cells grown with D-Aspartic acids. Other amino acids used as supplements failed to produce any impact on levels of testosterone and D-Aspartic acid.

Conclusion: An increase in testosterone levels was found amongst rats when their Leydig cells were cultured in the presence of D-Aspartic acid.

Source: http://www.ncbi.nlm.nih.gov/pubmed/8699926


D-Aspartate increases production of testosterone in rat testes.

Study: D’Aniello and co conducted a study to determine the role D-Aspartic acid plays in the production of testosterone in rat testes. Rats were injected with D-Aspartic acid and the levels of reproductive hormones like testosterone, luteinizing hormones and progesterone were estimated along with D-Aspartic acid level. Simultaneously, the authors studied the effect of adding D-Aspartic acid to the dissected rats and estimated the uptake.

Results: The authors found that D-Aspartate accumulated in testes and induced the production of testosterone by approximately 4 times higher than the normal base levels.

Conclusion: D-Aspartic acid leads to increased production of testosterone in rat testes.

Source: http://www.ncbi.nlm.nih.gov/pubmed/8699926


D-aspartic acid induces the production of steroids in frog brain.

Study: In two separate studies, Maria D Foire’s group has proven that enzymatic targets triggered by D-Aspartic acid led to the production and regulation of estradiol (steroid) in frog brains. The frogs were administered with D-Aspartic acid before and after the reproductive phase and levels of proteins like P450 aromatase and estradiol (which were essential for fertility) were estimated.

Result: D-Aspartic acid increased estradiol levels exclusively in the reproductive phase via the action of enzyme P450 aromatase.

Conclusion: D-Aspartic acid also modulates steroids like estradiol.

Source: http://jeb.biologists.org/content/215/20/3559.long


In addition to these studies, there is currently a large human clinical trial taking place, and the results are expected to be released later this year.


Studies on mammalian, avian (birds), amphibian (frogs) and human subjects strongly indicate that D-Aspartic acid positively regulates testosterone levels without causing any side effects. The role of testosterone in general wellbeing and vitality has been established with significant evidence. Boosting the testosterone levels helps in building muscle mass, increasing strength, improving stamina and enhancing fertility. These studies support the role of D-Aspartic acid in improving testosterone levels, suggesting that a D-aspartic acid testosterone booster can prove extremely beneficial.


Based on the lack of side effects and its overall effectiveness, d-aspartic acid is actually the no.1 ingredient that I look for in a testosterone supplement.

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