Huperzine A is a reversible acetylcholinesterase inhibitor and NMDA receptor antagonist that crosses the blood-brain barrier. A 2013 meta-analysis found that huperzine A may be efficacious in improving cognitive function, global clinical status, and activities of daily living for individuals with Alzheimer's disease.
Huperzine A is also marketed as a dietary supplement with claims made for its ability to improve memory and mental function. Huperzine A may also have a possible role in the treatment of myasthenia gravis.