Huperzine A is a compound that comes from a type of moss. It has been used to improve brain function and slow signs of dementia. Huperzine A can be taken as a pill or powder. It can also be injected into the muscle by a healthcare provider.


200 micrograms 2 to 4 times daily

What Research Shows

Likely Effective

Not Enough Data to Assess

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Safety Notes

It is likely safe for most adults to take huperzine A in small doses for a short time, but nausea, vomiting, and diarrhea may happen. Not enough studies have been done to say whether it is safe to use for a long period. It also may not be safe to take by women who are pregnant or breastfeeding.


Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse.


REFA Alzheimer Disease

REFA1 Li J, Wu HM, et al. Huperzine A for Alzheimer’s disease. Cochrane Database Syst Rev. 2008;(2):CD005592.

REFA2 Yang G, Wang Y, et al. Huperzine A for Alzheimer’s disease: a systematic review and meta-analysis of randomized clinical trials. PLoS One. 2013;8(9):e74916.

REFA3 Laver K, Dyer S, et al. Interventions to delay functional decline in people with dementia: a systematic review of systematic reviews. BMJ Open. 2016 Apr 27;6(4):e010767.

REFA4 Perng CH, Chang YC, et al. The treatment of cognitive dysfunction in dementia: a multiple treatments meta-analysis. Psychopharmacology (Berl). 2018 May;235(5):1571-1580.

REFA5 Liang J, Li J, et al. Identification of the optimal cognitive drugs among Alzheimer's disease: a Bayesian meta-analytic review. Clin Interv Aging. 2018 Oct 18;13:2061-2073.

REFA6 Cui CC, Sun Y, et al. The effect of anti-dementia drugs on Alzheimer disease-induced cognitive impairment: A network meta-analysis. Medicine (Baltimore). 2019 Jul;98(27):e16091.

REFB Cocaine Use Disorder

REFB1 De La Garza R 2nd, Verrico CD, et al. Safety and Preliminary Efficacy of the Acetylcholinesterase Inhibitor Huperzine A as a Treatment for Cocaine Use Disorder. Int J Neuropsychopharmacol. 2015 Sep 12;19(3):pyv098.

REFC Mild Cognitive Impairment

REFC1 Yue J, Dong BR, et al. Huperzine A for mild cognitive impairment. Cochrane Database Syst Rev. 2012 Dec 12;12:CD008827.

REFD Schizophrenia

REFD1 Zheng W, Xiang YQ, et al. Adjunctive huperzine A for cognitive deficits in schizophrenia: a systematic review and mate-analysis. Hum Psychopharmacol. 2016;31(4):268-295.

REFE Vascular Dementia

REFE1 Hao Z, Liu M, et al. Huperzine A for vascular dementia. Cochrane Database Syst Rev. 2009;(2):CD007365.

Revision Information

  • Reviewer: EBSCO NAT Review Board Eric Hurwitz, DC
  • Review Date: 02/2020
  • Update Date: 05/27/2020