Three grams D-aspartic acid raises testosterone levels by a third.
Taking a supplement that is based on an amino acid found naturally in the body increases the production of the messenger hormone LH and the muscle building testosterone in the pituitary gland and the testes, by enhancing the cellular production of signal molecules that control the secretion of LH and testosterone.
D-aspartic acid is formed when the enzyme aspartate racemase converts L-aspartic acid into D-aspartic acid in the testes and other glands. This amino acid plays a key role in the manufacture of sperm cells and sex hormone. That’s why the Italian pharmaceuticals company Pharmaguida markets the amino acid in products like Dadavit, which is aimed at infertile men.
The researchers gave a couple of dozen men aged between 27 and 37 a daily dose of 3.12 grams D-aspartic acid for twelve days consecutively. Twenty other men were given a placebo. The testosterone level in the subjects that received the supplement had risen by 33 percent after the twelve days, as the table below shows.
Basal Levels
LH (mIU/ml serum) D-aspartic acid (4.2+0.5) Placebo (4.2+0.4)
Test (ng/ml serum) D-aspartic acid (4.05+0.6) PLacebo (4.6+0.5)
After 6 Days
LH (mIU/ml serum) D-aspartic acid (4.05+0.6) Placebo (4.3+0.7)
Test (ng/ml serum) D-aspartic acid (5.2+0.7) Placebo (4.5+0.7)
After 12 Days
LH (mIU/ml serum) D-aspartic acid (5.6+0.9) Placebo (4.3+0.6)
Test (ng/ml serum) D-aspartic acid (6.4+0.8) Placebo (4.7+0.7)
3 Days after the Suspension of D-Aspartic Acid
LH (mIU/ml serum) D-aspartic acid (4.8+0.8) Placebo (4.1+0.5)
Test (ng/ml serum) D-aspartic acid (5.8+0.6) Placebo (4.6+0.7)
The Italians studied the mechanism involved using rats. The rats were given the amino acid in their drinking water. The figure below shows the effects of twelve days of supplement administration on the concentration of the amino acid in the pituitary and the testes of the rats.
[No Graph]
In the pituitary gland, D-aspartic acid increased the concentration of cGMP. cGMP is a signal molecule – or a second messenger – that transfers messages in the pituitary cells from other messenger hormones to the DNA. More cGMP means more LH. In the testes D-aspartic acid plays a similar role with the signal molecule cAMP, via which D-aspartic acid raises testosterone secretion.
Source:
Reprod Biol Endocrinol. 2009 Oct 27;7:120.