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Huperzine A

What You Need to Know About Huperzine A

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Updated May 22, 2014

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Huperzia serrata (syn. Lycopodium serratum)
Keisotyo/Wikimedia Commons/CC BY-SA 3.0

Huperzine A is a substance extracted from a plant called Chinese club moss (Huperzia serrata). In traditional Chinese medicine, Chinese club moss has long been used to reduce inflammation and to sharpen memory. Sold as a dietary supplement, huperzine A is typically touted as a treatment for Alzheimer's disease.

Uses for Huperzine A

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, and aid in the treatment of myasthenia gravis (an autoimmune disorder that affects the muscles).

Benefits of Huperzine A

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

1) Alzheimer's Disease

Huperzine A appears to be of some benefit to people with Alzheimer's disease, according to a 2008 research review published in the Cochrane Database of Systematic Reviews.

For the review, researchers searched for all randomized controlled trials on the efficacy and safety of huperzine A for Alzheimer's disease. In their analysis of the six available trials (which included a total of 454 patients), the researchers found that huperzine A was more effective than placebo in terms of its effects on cognitive function, behavioral disturbance, and functional performance.

However, the authors of the report caution that only one trial included in the review was "of adequate quality and size." Therefore, the authors note that there is "inadequate evidence to make any recommendation" about the use of huperzine A for the treatment of Alzheimer's disease.

In a more recent study (published in Neurology in 2011), 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.

2) 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.

Is Huperzine A Safe?

To date, little is known about the safety of taking huperzine A in the long term.

However, there's some concern that use of huperzine A may be harmful to people with certain health conditions (including kidney and/or liver disorders, heart disease, asthma, and vertigo) or people using certain medications (such as other cholinesterase inhibitors, beta-blockers, and anti-convulsive agents). Given these safety concerns, it's important to consult your physician if you're considering the use of huperzine A.

Additionally, huperzine A may cause a number of side effects (including diarrhea, dizziness, and cramps).

Where to Find Huperzine A

Widely available for purchase online, huperzine A is sold in many natural-food stores and in stores specializing in dietary supplements.

Should You Use Huperzine A for Health Purposes?

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 doctor before starting your supplement regimen.

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

Sources

Li J, Wu HM, Zhou RL, Liu GJ, Dong BR. "Huperzine A for Alzheimer's disease." Cochrane Database Syst Rev. 2008 Apr 16;(2):CD005592.

Rafii MS, Walsh S, Little JT, Behan K, Reynolds B, Ward C, Jin S, Thomas R, Aisen PS; Alzheimer's Disease Cooperative Study. "A phase II trial of huperzine A in mild to moderate Alzheimer disease." Neurology. 2011 Apr 19;76(16):1389-94.

Sun QQ, Xu SS, Pan JL, Guo HM, Cao WQ. "Huperzine-A capsules enhance memory and learning performance in 34 pairs of matched adolescent students." Zhongguo Yao Li Xue Bao. 1999 Jul;20(7):601-3.

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