Clinical efficacy and safety of tanakan has been studied in 30 patients with the syndrome of mild cognitive impairment. The results suggest a clear therapeutic effect of the 6 month course therapy. The efficacy of tanakan was confirmed by significant improvement of cognitive functioning of patients measured with MMSE, MDRS, FAST and other scales. The feature of tanakan effect is its positive influence on memory and other cognitive functions that allows the use of the drug in the treatment of elderly people with the syndrome of mild cognitive impairment. The safety of tanakan used in high therapeutic dosages (240 mg daily) and its good tolerability during chronic administration are revealed.