About Huperzine A
An alkaloid from Huperzia serrata that reversibly inhibits acetylcholinesterase. Several small Chinese RCTs suggest cognitive benefit in Alzheimer's, but trial quality is low and a Cochrane review judged evidence inadequate. As a cholinesterase inhibitor it is pharmacologically active and not benign at high doses. ⚠️ Additive with prescription cholinesterase inhibitors (donepezil, rivastigmine, galantamine) and opposes anticholinergic drugs — do not combine.
What Huperzine A supports
- Acetylcholinesterase inhibitor studied for memory
How much Huperzine A to take
The RDA prevents deficiency. The effective range is what clinical trials used to actually move the outcome.
Effective
50–400
mcg
Cognitive trials used 50-200 mcg twice daily (up to 400 mcg/day total; the positive Phase II Alzheimer's arm used 400 mcg/day). Note: dosed in micrograms, not milligrams.
Clinical evidence
Limited clinical evidence. Small low-quality RCTs; Cochrane judged evidence inadequate
Examine.com