Huperzine-A is a cognition-enhancing compound found in the Asian plant families of Huperziaceae, Lycopodiaceae, and Selaginella. Sometimes it goes by the name Chinese Club Moss.
The compound itself is known as an acetylcholinesterase inhibitor, which means that it inhibits an enzyme from breaking down acetylcholine (the brains primary “learning” neurotransmitter) which results in increases in acetylcholine above baseline levels.
The real benefit Huperzine-A is simply the byproduct of the natural increase of acetylcholine. As a neurotransmitter, acetylcholine plays a role in the following:
- Central nervous system activity
- Peripheral nervous system activity
- Muscular activity
- Sensory enhancement
- Information storage and retrieval
Huperzine-A appears to be a safe compound from animal studies of toxicity and studies in humans showing no side-effects at standard dosages.
The most commonly reported side effects are due to high dosages and include nausea, diarrhea, vomiting and other gastrointestinal-related effects. For this reason, it’s recommended to always follow the package dosage directions.
Huperzine-A dosing tends to be in the range of 50-200mcg daily. It’s equally common to either divide the does up into equal amounts throughout the day or take a single dose in the morning.
Orally administered huperzine-A is quickly absorbed into the blood stream and can take effect in as little as 15 minutes and peak at around 70 minutes post-ingestion.
Lastly, cycling huperzine-A is highly recommended due to its long half-life (over 24 hours). Supplemental huperzine-A should be taken no longer than 4 weeks without a 2-4 week break to optimize effectiveness.
-  Effects of huperzine A on acetylcholinesterase isoforms in vitro: comparison with tacrine, donepezil, rivastigmine and physostigmine.
-  “Huperzine a for Alzheimer’s Disease: A Systematic Review and Meta-Analysis of Randomized Clinical Trials”
-  Pharmacokinetics of huperzine A following oral administration to human volunteers.