HUPERZINE A

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).1

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.

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:

Huperzine A appears to be of some benefit to people with Alzheimer's disease, according to a 2013 research review published in PLoS One.2 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.3

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.4

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.5

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.1

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.

Interactions

Huperzine A may interact with certain medications including cholinesterase inhibitors, beta-blockers, and anti-convulsive agents.6 Given these safety concerns, it's important to consult your healthcare provider if you're considering the use of huperzine A.

Huperzine A comes in tablets and capsules, and is an added ingredient in several combination supplements touted as memory enhancers.6

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