I tried L-Glutamine after complete colon cleanse and Candida treatment called ThreeLac. Insomnia was one of the symptoms that surprisingly disappeared. While L-Glutamine is an amino acid, and supports the body in many ways, I learned through this experience (and the guidance of a very good Holistic Chiropractor) that when this amino acid is first introduced into the body, the colon just loves it, and sucks it up. As the mucous membranes of the colon are regenerated, insomnia is one of the symptoms that fall to the wayside. I did use the L-Glutamine after a round of the candida treatment, which irradicates an overgrowth of Candida and helps to balance the pH levels of the colon and body. There is also product called HGH at night, which is rich in L-Glutamine, but this is not the original source that I took. I originally took a powder form, about 1,500 mcg. daily, first thing in the morning, as it is loaded with protein and jump starts the metabolism.