Scientific Names: Huperzia serrata
Other Common Names: Huperzine, HupA, selagina. Huperzine A is derived from Chinese club moss
Overall Safety: 😐
Therapeutic Efficacy and Considerations:
Alzheimer’s Disease: 😐 Only one of the several clinical trials evaluating huperzine A for dementia in Alzheimer’s disease has been published in English. The trial demonstrated improvement in memory, cognition, and behavior over an 8-week period. Usual dose is 50-200 mcg given twice a day.
Memory Improvement: 😐 One moderately sized trial found a statistically significant improvement in memory over 4 weeks. However, methodological considerations limit usefulness of the results; for example, subjects were adolescents, and it is unknown if results could be extrapolated to other age groups more likely to be interested in a memory-enhancing supplement. Usual dose is 100 mcg given twice a day.
Memory Improvement: 😐 One moderately sized trial found a statistically significant improvement in memory over 4 weeks. However, methodological considerations limit usefulness of the results; for example, subjects were adolescents, and it is unknown if results could be extrapolated to other age groups more likely to be interested in a memory-enhancing supplement. Usual dose is 100 mcg given twice a day.
Chemistry/Pharmacology:
Huperzine A is a purified alkaloid component derived of the Huperzia serratia and Lycopodium selago or L. serratum plants. The levorotatory isomer is a reversible acetylcholinesterase inhibitor. It exhibits rapid absorption and penetration of the blood brain barrier and its duration of action in the brain of 3 hours is longer than prescription acetylcholinesterase inhibitors. It increases acetylcholine by 105-125%, is a weak non-competitive NMDA receptor antagonist, and may prevent beta-amyloid plaque formation. Huperzine A is currently being studied for use with tacrine and donepezil.
Drug Interactions:
May cause a hypertensive crisis when given with an MAOI. May have additive effects with other cholinergic drugs or other AChE inhibitors. Anticholinergic drugs may decrease its effects.
Contraindications/Precautions:
Contraindicated in patients with bradycardia, myocardial infarction, seizure disorders, Parkinson’s disease, asthma, and chronic obstructive pulmonary disease. Use with caution in patients with peptic ulcer disease and urogenital or gastrointestinal obstruction.
Adverse Effects:
May cause decreased heart rate, hyperactivity and insomnia, involuntary muscle contractions, dizziness, slurred speech, blurred vision, nausea, vomiting, diarrhea, cramps, incontinence, and increased sweat, saliva, and tear production.