Huperzia

Common names: Qian ceng ta, Huperzine A

Parts used and where grown: Huperzia is a type of moss that grows in China. It is related to club mosses (the Lycopodiaceae family) and is known to some botanists as Lycopodium serratum. The whole prepared moss was used traditionally. Modern herbal preparations use only the isolated alkaloid known as huperzine A.

Huperzia has been used in connection with the following conditions (refer to the individual health concern for complete information):

Rating Health Concerns
2Stars Age-related cognitive decline
Alzheimer’s disease
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star An herb is primarily supported by traditional use, or the herb or supplement has little scientific support and/or minimal health benefit.

Historical or traditional use (may or may not be supported by scientific studies): Huperzia moss tea has been used for centuries in traditional Chinese herbalism for fever, as a diuretic, for blood loss, and for irregular menstruation.1

Active constituents: Huperzine A is an alkaloid found in huperzia that has been reported to prevent the breakdown of acetylcholine, an important substance needed by the nervous system to transmit information from cell to cell.2 Animal research has suggested that huperzine A’s ability to preserve acetylcholine may be greater than that of some prescription drugs.3 4 Loss of acetylcholine function is a primary feature of several disorders of brain function, including Alzheimer’s disease. Huperzine A may also have a protective effect on brain tissue, further increasing its theoretical potential for helping reduce symptoms of some brain disorders.5 6

In a double-blind trial, people with Alzheimer’s disease had significant improvement in memory and cognitive and behavioral functions after taking 200 mcg of huperzine A twice per day for eight weeks.7 Another double-blind trial using injected huperzine A confirmed a positive effect in people with dementia, including, but not limited to, Alzheimer’s disease.8 Another double-blind trial found that huperzine A (100–150 mcg two to three times per day for four to six weeks) was more effective for improving minor memory loss associated with age-related cognitive decline than the drug piracetam.9

Huperzine A has also been shown to enhance memory in adolescent middle school students. A small controlled trial found that 100 mcg of huperizine A two times per day for four weeks was effective in improving memory and learning performance.10 Although no side effects were reported in this short trial, long-term safety studies are needed before huperizine A is recommended for adolescents or younger children to improve memory and learning performance.

How much is usually taken? Human research on huperzine A has used 100–200 mcg taken two to three times per day.11

Are there any side effects or interactions? Medications that prevent acetylcholine breakdown often produce side effects, including nausea, vomiting, excess saliva and tear production, and sweating. However, while dizziness was reported in a few people in one study, no severe side effects have been reported in human trials using huperzine A. Further studies are needed to determine the long-term safety of huperzine A.

Are there any drug interactions? Certain medications may interact with huperzia. Refer to the drug interactions safety check for a list of those medications.

References:

1. Kozikowski AP, Tückmantel W. Chemistry, Pharmacology, and Clinical Efficacy of the Chinese Nootropic Agent Huperzine A. www.huperzine.net/invent.htm, 26 June 2000.

2. Ashani Y, Peggins JO, Doctor BP. Mechanism of inhibition of cholinesterases by huperzine A. Biochem Biophys Res Commun 1992;184:719–26.

3. Cheng DH, Tang XC. Comparative studies of huperzine A, E2020, and tacrine on behavior and cholinesterase activities. Pharmacol Biochem Behav 1998;60:377–86.

4. Cheng DH, Ren H, Tang XC. Huperzine A, a novel promising acetylcholinesterase inhibitor. Neuroreport 1996;8:97–101.

5. Ved HS, Koenig ML, Dave JR, et al. Huperzine A, a potential therapeutic agent for dementia, reduces neuronal cell death caused by glutamate. Neuroreport 1997;8:963–8.

6. Skolnick AA. Old Chinese herbal medicine used for fever yields possible new Alzheimer’s disease therapy [news item]. JAMA 1997;277:776.

7. Xu SS, Gao ZX, Weng Z, et al. Efficacy of tablet huperzine-A on memory, cognition, and behavior in Alzheimer’s disease. Chung Kuo Yao Li Hsueh Pao 1995;16:391–5.

8. Zhang RW, Tang XC, Han YY, et al. Drug evaluation of huperzine A in the treatment of senile memory disorders. Chung Kuo Yao Li Hsueh Pao 1991;12:250–2 [in Chinese].

9. Wang Z, Ren G, Zhao Y, et al. A double-blind study of huperzine A and piracetam in patients with age-associated memory impairment and dementia. In: Kanba S, Richelson E (eds). Herbal Medicines for Nonpsychiatric Diseases. Tokyo: Seiwa Shoten Publishers, 1999, 39–50.

10. Sun QQ, Xu SS, Pan JL, et al. Huperizine-A capsules enhance memory and learning performance in 34 pairs of matched adolescent students. Acta Pharmacol Sin 1999;20:601–3.

11. Qian BC, Wang M, Zhou ZF, et al. Pharmacokinetics of tablet huperzine A in six volunteers. Chung Kuo Yao Li Hsueh Pao 1995;16:396–8.