Huperzine A
Content by: OpenSupplement Editorial Team | Medical review: pending | Last updated: April 13, 2026
TL;DR
Natural alkaloid from club moss that stops the breakdown of acetylcholine
Moderate-to-high evidence for improving memory in Alzheimer's and students
Acts like a natural version of the drug Aricept (Donepezil)
Must be cycled (taken with breaks) to maintain effectiveness
Inexpensive: ~$8-15/month
Best for: Memory recall, short-term focus, cognitive support
What it is
Huperzine A is an 'acetylcholinesterase inhibitor.' While Alpha-GPC adds more acetylcholine to the brain, Huperzine A prevents the 'cleanup' enzyme from removing it. This creates a powerful 'synergy' when used together, though it must be used with care.
What the research says
Huperzine A is highly potent. Evidence. Systematic reviews of clinical trials in China have shown that Huperzine A significantly improves memory and cognitive function in patients with Alzheimer's and vascular dementia. It is one of the few natural substances that works directly on the same pathway as multi-billion dollar pharmaceuticals. [1][2][3]
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Huperzine A on Amazon
Safety
Generally safe but potent. Side effects can include nausea, sweating, and restlessness if the dose is too high. Important: Because it has a long half-life, it should be cycled (e.g., 5 days on, 2 days off) to prevent desensitization.
Interactions
- Anticholinergic Drugs: May interfere with medications for COPD or overactive bladder.
- Alzheimer's Meds: Do not combine with Aricept or Exelon without a doctor.
Dosing
Standard Dose: 100-200 mcg (micrograms) daily. Warning: Do not confuse 'mg' with 'mcg'—this is a very small, precise dose.
Cost
Affordable. $8-15 per month.
The bottom line
Huperzine A is a 'sharpness' supplement. It's highly effective for memory, but its potency means it should be respected and used with breaks.
References
- Zhang Z, Wang X, Chen Q, et al. Clinical efficacy and safety of huperzine Alpha in treatment of mild to moderate Alzheimer disease, a placebo-controlled, double-blind, randomized trial. Zhonghua Yi Xue Za Zhi. 2002;82(14):941-944.
- Wang BS, Wang H, Wei ZH, et al. Efficacy and safety of natural acetylcholinesterase inhibitor huperzine A in the treatment of Alzheimer's disease: an updated meta-analysis. J Neural Transm (Vienna). 2009;116(4):457-465.
- Rafii MS, Walsh S, Little JT, et al. A phase II trial of huperzine A in mild to moderate Alzheimer disease. Neurology. 2011;76(16):1389-1394.
Sources for this page include published meta-analyses, systematic reviews, and NIH dietary supplement fact sheets. All claims reflect the evidence as of early 2026.
This is not medical advice. Consult your healthcare provider before starting any supplement, especially if you take medications.