"As to salts, this last recipe above, taken from the literature, is the only claim of a valid hydrochloride salt of DMT. In the original synthesis, by Manske, the following description appears. "The hydrochloride could be obtained only as a pale yellow resin which, when dried in a vacuum desiccator over potassium hydroxide, became porous and brittle." I have found no attempts at its synthesis in the literature, and I have personally had no success at all. The picrate salt is well defined, used mostly for isolation and purification. The oxalate is used occasionally in animal studies. Early human studies involving the injection of solutions of the hydrochloride apparently made by dissolving DMT base in dilute aqueous HCl, and neutralizing this with base to achieve an end pH of appropriate 6. The fumarate is the salt specifically approved by the FDA for human studies, and this was the form used for human intravenous injection employed in the recent New Mexico studies."