Huperzine A is a naturally occurring sesquiterpenealkaloid compound found in the firmossHuperzia serrata and in varying quantities in other food Huperzia species, including H. elmeri, H. carinat, and H. aqualupian. Huperzine A has been investigated as a treatment for neurological conditions such as Alzheimer's disease, but a meta-analysis of those studies concluded that they were of poor methodological quality and the findings should be interpreted with caution. Huperzine A inhibits the breakdown of the neurotransmitter acetylcholine by the enzyme acetylcholinesterase. It is commonly available over the counter as a nutrient supplement, and is marketed as a cognitive enhancer for improving memory and concentration.
For some years, huperzine A has been investigated as a possible treatment for diseases characterized by neurodegeneration, particularly Alzheimer's disease. A 2013 meta-analysis found that huperzine A may be efficacious in improving cognitive function, global clinical status, and activities of daily living for individuals with Alzheimer’s disease. However, due to the poor size and quality of the clinical trials reviewed, huperzine A should not be recommended as a treatment for Alzheimer’s disease unless further high quality studies confirm its beneficial effects.
Huperzine A is also marketed as a dietary supplement with claims made for its ability to improve memory and mental function.
Huperzine A may present with mild cholinergic side effects such as nausea, vomiting, and diarrhea. The use of huperzine A during pregnancy and lactation is not recommended due to the lack of sufficient safety data.
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