Chelated D-Aspartate with Sarcosine. Dual Action Natural Testosterone Elevator. D-Aspartic acid is an obscure natural amino acid that has been shown to raise testosterone levels in men. TestForce 2 has improved on the absorption and bio-availability of regular D-Aspartic Acid by chelating it with calcium-thereby increasing its water solubility over 75 times. This calcium chelated form of D-Aspartic acid is remarkably stable over a wide pH range and will mix instantly. TestForce 2 also contains the amino acid Sarcosine, which works synergistically with D-Aspartic Acid to greatly enhance its activity at the receptor. Daily use of TestForce 2 as directed will lead to gradual elevation of testosterone that peaks in approximately three to five weeks. Continued usage maintains peak testosterone levels.