This one was for 4 weeks at 200mcg on middle school student:
In 1999, Chinese researchers found, in a study designed to determine the efficacy of HuperzineA on memory and learning in adolescents, that similar results were observed to trila swith adults. They selected 34 matched pairs of apparently normal junior middle school students whose only significant complaints were of poor memory and difficulty in learning. The pairing was done in terms of age, sex, memory quotient, and overall psychological health, to ensure that comparisons would be meaningful. Using these criteria, the researchers found no statistically significant baseline differences between the students in the two groups, one of which was to be treated with HuperzineA, the other to receive a placebo. In a double-blind trial, one member of each pair, chosen randomly, was given 100 micrograms of synthetic HupA twice daily for four weeks, while the other member received the placebo. The students' memory quotients were measured before and after the trial, and their academic performance in their Chinese, English, and mathematics lessons was monitored as well. At the end of the study, the HuperzineA group scored significantly better than the control group on standard memory tests described as "accumulation," "recognition," "reproduction," "association," "tactual [tactile] memory," and "number of recitation," but not on tests of "picture memory" or "understanding." They had also done significantly better in their Chinese and English lessons, but not in math. No side effects of any kind were noted (Xu SS, Cai ZY, Qu ZW, Yang RM, Cai YL, Wang GQ, Su XQ, Zhong XS, Cheng RY, Xu WA, Li JX, Feng B. Huperzine-A in capsules and tablets for treating patients with Alzheimer's disease. Acta Pharmacol Sin 1999 Jun;20(6):486-90).