Huperzine A is a purified nutrient that is commonly found in the Huperziaspecies. Huperzia is a Chinese herb. Huperzine A exhibits acetylcholinesterase properties. That is, it acts at neuronal synapses to increase the levels of acetylcholine, which in turn improves the activity at the synapse. The cognitive effects of huperzine A has been studied to a mild extent, in particular with respect to its effects on Alzheimer’s disease patients.
*Huperzine A is a purified nutrient normally derived from Chinese club moss. *
Pharmacologically, huperzine A has been known to inhibit the enzyme acteylcholinesterase. This binding results in the inhibition of the enzyme, thereby increasing the amount of acetylcholine available in a neuronal synapse.
It has been shown that after ingestion, it takes about 1 hour for huperzine A to reach peak levels in the bloodstream.
Huperzine A and Cognition
While huperzine A has not been widely studied, there exists some promising literature that indicates huperzine A may be helpful for improving attention and memory.
In the context of Alzheimer’s disease, there have been several randomized control trials studying the cognitive effects of huperzine A in older individuals who suffer from the disease. It is particularly interesting that huperzine A was found to significantly improve general cognitive performance (with respect to short term memory and executive function) as measured by the Mini Mental Status Examination (MMSE) in a cohort of 454 patients (P < 0.00001).4
One study on normal human volunteers (n=36, 12 individuals in each treatment group) showed that huperzine A at 100 micrograms and 200 micrograms did not result in improved cognitive performance with respect to short term memory (as measured by the learning/immediate recall and delayed recall tasks (P>0.05)) when compared with both placebo and galantamine, a drug normally used to treat alzheimers.2Studies like this should motivate further research that distinguishes differences in cognitive effects between normal humans and patients with cognitive deficits.
Reported side effects of huperzine A include nausea, vomiting and diarrhea.