Huperzine A, an alkaloid isolated from Huperzia serrata, is a putative nootropic agent developed by the Chinese Academy of Sciences. Huperzine A is currently in phase III trials in China for the treatment of patients with Alzheimer's disease. The mechanism of action of huperzine A is suggested to be facilitated through the slow reversible inhibition of acetylcholinesterase. Marco Hi-Tech Joint Venture has exclusive worldwide marketing and distribution rights to huperzine A. Marco Hi-Tech Joint Venture is a corporation principally owned by Hi-Tech Pharmacal and Marco International, a global trading and finance firm formed to import huperzine A from China. Marco Hi-Tech Joint Venture also has rights to synthetic analogues of huperzine A. In July 2003, Savient Pharmaceuticals acquired the exclusive rights from Marco Hi-Tech to market huperzine A in Europe and the US. Clinical trials of huperzine A in elderly patients with age-associated memory loss are underway in the US, and a phase II study funded by an NCI grant is being planned.