Huperzine A
Meta-analyses of mostly Chinese trials found higher memory and daily living scores in Alzheimer's disease, but most trials had a high risk of bias. A 16-week US trial in 210 people found no change in its main cognitive measure at the lower dose. Trials in brain injury and in trained adults found no difference. Reported side effects were mostly cholinergic.
Add to Bio HackChecked 2026-11-09
- Status
- Sold as a dietary supplement in the US. Not FDA-approved for any condition.
- Also called
- HupA, Hup A, huperzine, Huperzia serrata, Chinese club moss, qian ceng ta, shuangyiping
- Taken for
- memory, focus, Alzheimer's disease, dementia, mild cognitive impairment, brain injury recovery, pre-workout focus
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Shown to help0
No benefit shown in research yet.
What people take it for, and what was found
Mixed results2
Cognition in Alzheimer's disease
Mixed results: mostly Chinese trials found higher MMSE scores, about 2.8 points, while a US trial found no change in its main outcome at the lower dose.
The numbers and sources
- Effect
- A Cochrane review of 6 trials (454 patients) found higher MMSE scores on huperzine A than placebo (weighted mean difference 2.81 points, 95% CI 1.87 to 3.76) [1]. A review of 20 trials (1,823 participants) found higher MMSE scores at 8, 12 and 16 weeks and better daily living scores. The one trial using ADAS-Cog found no change [2]. A 4-trial meta-analysis of 300 to 500 mcg a day for 8 to 24 weeks found higher MMSE and daily living scores [3], and an 8-trial analysis (733 participants) agreed [4]. In a 16-week US trial of 210 people, 200 mcg twice a day did not change ADAS-Cog, the main outcome. At 400 mcg twice a day, ADAS-Cog improved 2.27 points at 11 weeks against a 0.29-point decline on placebo, and 1.92 against 0.34 points at 16 weeks (p 0.07). Global impression, behavior and daily living did not differ at either dose [5].
- Population
- People with Alzheimer's disease, mostly in China, 8 to 24 weeks [1][2][3][4]. 210 people with mild to moderate disease in the US [5].
- Sources
- [1], [2], [3], [4], [5]
- Caveats
- The sources disagree. The Cochrane review found only one trial of adequate quality and size [1], and most trials in [2] had a high risk of bias. The US trial was funded by the National Institute on Aging [5].
Vascular dementia
Limited evidence: one 14-person trial found no significant MMSE difference in vascular dementia, while a 2-trial analysis reported higher scores.
The numbers and sources
- Effect
- A Cochrane review found one trial of 14 people. MMSE scores did not differ significantly (weighted mean difference 2.40, 95% CI -4.78 to 9.58) [6]. An analysis including 2 trials (92 participants) reported higher MMSE and daily living scores [4].
- Population
- People with vascular dementia [6][4].
- Sources
- [6], [4]
- Caveats
- The Cochrane authors note intervals wide enough to include both clinically significant benefit and harm [6].
Not shown to help3
Mild cognitive impairment and dementia overall
Limited evidence: an overview of 6 reviews found too little evidence to draw conclusions for mild cognitive impairment and vascular dementia.
The numbers and sources
- Effect
- An overview of 6 systematic reviews found little or no evidence to draw conclusions for mild cognitive impairment and vascular dementia, and insufficient evidence on quality of life and global clinical assessment [7].
- Population
- Reviews of trials in dementia and mild cognitive impairment [7].
- Sources
- [7]
- Caveats
- The overview cites high heterogeneity among reviews and low-quality primary studies [7].
Memory after traumatic brain injury
One pilot trial found no difference in memory scores from placebo in adults with moderate to severe brain injury.
The numbers and sources
- Effect
- In a 12-week phase II trial, memory scores did not differ between huperzine A and placebo. Learning and memory improved in the placebo group, and depression scores improved in both groups [8].
- Population
- Adults with moderate to severe traumatic brain injury [8].
- Sources
- [8]
- Caveats
- A pilot trial. The abstract does not give the number of participants [8].
Focus and performance during exercise
One small trial found a single 200 mcg dose did not change cognition or performance in trained adults, and exercise felt harder.
The numbers and sources
- Effect
- In 15 trained adults, a single 200 mcg dose did not change any cognitive test (all p 0.296 or above), balance, dart throwing, aerobic capacity, grip strength, jump or push-ups compared with placebo. Rated difficulty after exercise was higher on huperzine A (6.8 against 5.7 on a 0 to 10 scale) [9].
- Population
- 11 women and 4 men, crossover design [9].
- Sources
- [9]
- Caveats
- One small single-dose trial.
Doses studied
Alzheimer's trials pooled in one meta-analysis used 300 to 500 mcg a day for 8 to 24 weeks [3]. The US trial tested 200 mcg and 400 mcg twice a day for 16 weeks [5]. The exercise trial used a single 200 mcg dose [9].
Risks
Reported risks1
Cholinergic side effects
Side effects were mostly cholinergic, mild and transient in Alzheimer's trials, with no serious events reported.
The numbers and sources
- Effect
- In a meta-analysis of 4 Alzheimer's trials, most adverse events were cholinergic and none were serious [3]. An 8-trial analysis reported mostly mild to moderate, transient adverse effects in Alzheimer's disease [4]. None of 20 trials in a 2013 review reported severe adverse events [2].
- Population
- People with Alzheimer's disease or vascular dementia in trials of up to 24 weeks [2][3][4].
- Sources
- [3], [4], [2]
- Caveats
- The abstracts do not give adverse event rates. Most trials were short and of low methodological quality [1][2].
Checked, no increase found1
Limited long-term safety data
Limited evidence: reviews found no serious side effects but only one trial of adequate quality and size, and no long-term follow-up.
The numbers and sources
- Effect
- The Cochrane review found only one trial of adequate quality and size [1]. The 2021 overview called for large trials with long-term follow-up and reported that none of the reviews found serious side effects [7].
- Population
- Reviews of dementia trials [1][7].
- Sources
- [1], [7]
- Caveats
- Absence of reported serious events in short, small trials does not rule them out.
Claims tested and not found
- That huperzine A improves memory after traumatic brain injury. Memory scores did not differ from placebo after 12 weeks [8].
- That huperzine A sharpens focus or performance during exercise. In trained adults, no cognitive or performance measure differed from placebo [9].
- That 200 mcg twice a day improves cognition in Alzheimer's disease. In the US phase II trial, ADAS-Cog did not change at that dose over 16 weeks [5].
Sources
- Li J, Wu HM, Zhou RL, et al. Huperzine A for Alzheimer's disease. Cochrane Database of Systematic Reviews. 2008. https://doi.org/10.1002/14651858.CD005592.pub2
- Yang G, Wang Y, Tian J, et al. Huperzine A for Alzheimer's Disease: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. PLoS ONE. 2013. https://doi.org/10.1371/journal.pone.0074916
- 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. Journal of Neural Transmission. 2009. https://doi.org/10.1007/s00702-009-0189-x
- Xing SH, Zhu CX, Zhang R, et al. Huperzine A in the Treatment of Alzheimer's Disease and Vascular Dementia: A Meta-Analysis. Evidence-Based Complementary and Alternative Medicine. 2014. https://doi.org/10.1155/2014/363985
- Rafii MS, Walsh S, Little JT, et al. A phase II trial of huperzine A in mild to moderate Alzheimer disease. Neurology. 2011. https://doi.org/10.1212/wnl.0b013e318216eb7b
- Hao Z, Liu M, Liu Z, et al. Huperzine A for vascular dementia. Cochrane Database of Systematic Reviews. 2009. https://doi.org/10.1002/14651858.CD007365.pub2
- Ghassab-Abdollahi N, Mobasseri K, Dehghani Ahmadabad A, et al. The effects of Huperzine A on dementia and mild cognitive impairment: An overview of systematic reviews. Phytotherapy Research. 2021. https://doi.org/10.1002/ptr.7126
- Zafonte RD, Fregni F, Bergin MJ, et al. Huperzine A for the treatment of cognitive, mood, and functional deficits after moderate and severe TBI (HUP-TBI): results of a Phase II randomized controlled pilot study: implications for understanding the placebo effect. Brain Injury. 2020. https://doi.org/10.1080/02699052.2019.1677941
- Wessinger CM, Inman CL, Weinstock J, et al. Effect of Huperzine A on Cognitive Function and Perception of Effort during Exercise: A Randomized Double-Blind Crossover Trial. International Journal of Exercise Science. 2021. https://doi.org/10.70252/gqbm6956