D Aspartic Acid (DAA) is one of the two dorms of the amino acid called aspartic acid. The other form of this amino acid is L-aspartate. Research shows DAA may help temporarily promote testosterone levels in healthy men giving them a temporary boost to athletic performance for 6-12 days. Double Wood’s D Aspartic Acid is Vegan Safe, Made in the USA, Non-Gmo, and Gluten Free. It contains 300 capsules and each serving is four 500mg capsules (2,000mg). This is enough D-Aspartic Acid to last 75 days if a full dose is taken.