The Health Benefits of Huperzine A

Huperzine A capsules and tablets

Verywell / Anastasia Tretiak

Huperzine A is a substance extracted from a plant called Chinese club moss (Huperzia serrata). Sold as a dietary supplement, huperzine A is typically touted as a treatment for Alzheimer's disease.

Used in alternative medicine, huperzine A has been found to act as a cholinesterase inhibitor, a type of medicine used to prevent the breakdown of acetylcholine (a chemical essential to learning and memory).

Not only used as a treatment for Alzheimer's disease, huperzine A is also said to enhance learning and memory and to protect against age-related cognitive decline.

In addition, huperzine A is sometimes used to boost energy, increase alertness, fight depression, and aid in the treatment of myasthenia gravis, an autoimmune disorder that affects the muscles. However, the research is limited.

Commonly Known As

  • Huperzine A
  • Selagine

Health Benefits

While research on the health effects of huperzine A is limited, there's some evidence that huperzine A may offer certain benefits. Here's a look at some key findings from the available research:

Alzheimer's Disease

Huperzine A appears to be of some benefit to people with Alzheimer's disease, according to a 2013 research review published in PLoS One. Researchers searched for all randomized controlled trials on the efficacy and safety of huperzine A for Alzheimer's disease and concluded that huperzine A was more effective than a placebo in terms of its effects on cognitive function, behavioral disturbance, and functional performance. This was also found in a 2008 review published in Cochrane Database of Systematic Reviews.

However, a 2011 study published in Neurology showed huperzine A failed to improve cognitive function in Alzheimer's patients. The study involved 210 people with mild to moderate Alzheimer's disease, each of whom received either huperzine A or a placebo for at least 16 weeks. In their analysis of the 177 participants who completed the study, researchers found that huperzine A did not have a significant effect on cognitive function.

Memory Enhancement

Very few studies have tested the use of huperzine A for memory enhancement. However, an older, small study published in the Chinese journal Acta Pharmacologica Sinica in 1999 found that huperzine A helped improve memory and learning in a group of adolescent students.

For the study, 68 junior high students (all of whom complained of memory inadequacy) were given either huperzine A or a placebo every day for four weeks. By the study's end, members of the huperzine A group showed greater improvements in learning and memory (compared to members of the placebo group).

More research is needed before huperzine A can be recommended for memory enhancement.

Possible Side Effects

Huperzine A may cause side effects including nausea, diarrhea, vomiting, dry mouth, constipation, sweating, blurred vision, slurred speech, fainting, restlessness, loss of appetite, contraction and twitching of muscle fibers, cramping, increased saliva and urine, inability to control urination, high blood pressure, swelling, dizziness, inability to sleep, and slowed heart rate.

Little is known about the safety of taking huperzine A in the long term. There is some concern that the use of huperzine A may be harmful to people with certain health conditions, including kidney and/or liver disorders, heart disease, asthma, epilepsy, and vertigo.


Huperzine A may interact with certain medications including cholinesterase inhibitors, beta-blockers, and anti-convulsive agents. Given these safety concerns, it's important to consult your healthcare provider if you're considering the use of huperzine A.

Huperzine A capsules

Verywell / Anastasia Tretiak

Dosage and Preparations

Huperzine A comes in tablets and capsules, and is an added ingredient in several combination supplements touted as memory enhancers.

There is no recommended daily allowance for huperzine A. The following doses have been studied:

  • Alzheimer's disease: 300 mcg to 500 mcg daily
  • Dementia: 100 mcg twice daily
  • Memory booster: 100 mcg twice daily

What To Look For

When selecting a brand of supplements, look for products that have been certified by Consumer Labs, The U.S. Pharmacopeial Convention, or NSF International. 

A Word From Verywell

Due to a lack of supporting research, huperzine A cannot currently be recommended for treatment or prevention of any health problem. If you're considering the use of huperzine A supplements, consult your healthcare provider before starting your supplement regime to weigh the risks, benefits, and appropriateness.

It's important to note that self-treating Alzheimer's disease (or any other condition) with huperzine A and avoiding or delaying standard care may have serious health consequences.

Frequently Asked Questions

  • Will huperzine A improve my workout?

    It is possible but not guaranteed that huperzine A will improve workout and exercise. Early studies suggest it may enhance concentration and focus, but there is a lack of supporting evidence to be certain of these benefits. The safety of the supplement is currently unknown.

  • What is a nootropic?

    A nootropic is a chemical that is intended to enhance mental performance. They are available as over-the-counter drugs, prescription drugs, and dietary supplements, such as huperzine A. Over-the-counter and prescription nootropics are approved by the FDA and have specific use cases, such as treating Alzheimer's disease and attention-deficit hyperactivity disorder (ADHD). Since nootropic dietary supplements do not require FDA approval, some of them may hide every ingredient used in their preparation, making them potentially unsafe.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Xing SH, Zhu CX, Zhang R, An L. Huperzine A in the treatment of Alzheimer's disease and vascular dementia: A meta-analysisEvid Based Complement Alternat Med. 2014;2014:363985. doi:10.1155/2014/363985

  2. Yang G, Wang Y, Tian J, Liu JP. Huperzine A for Alzheimer's disease: a systematic review and meta-analysis of randomized clinical trials. PLoS One. 2013;8(9):e74916. doi:10.1371/journal.pone.0074916

  3. Li J, Wu HM, Zhou RL, et al. Huperzine A for Alzheimer's disease. Cochrane Database Syst Rev. 2008;(2):CD005592. doi:10.1002/14651858.CD005592.pub2

  4. Rafii MS, Walsh S, Little JT, et al; Alzheimer's Disease Cooperative Study. A phase II trial of huperzine A in mild to moderate Alzheimer disease. Neurology. 2011;76(16):1389-94. doi:10.1212/WNL.0b013e318216eb7b

  5. Sun QQ, Xu SS, et al. Huperzine-A capsules enhance memory and learning performance in 34 pairs of matched adolescent students. Zhongguo Yao Li Xue Bao. 1999;20(7):601-3.

  6. Zhang HY. New insights into huperzine A for the treatment of Alzheimer's diseaseActa Pharmacol Sin. 2012;33(9):1170–1175. doi:10.1038/aps.2012.128

  7. Uniformed Services University (USU). The Department of Defense Dietary Supplement Resource. Operation Supplement Safety. Huperzine A: Dietary Supplements for Brain Health.

  8. Uniformed Services University (USU). The Department of Defense Dietary Supplement Resource. Operation Supplement Safety. Nootropics: Drugs vs. Dietary Supplements for Brain Health.