Our evidence-based analysis of Huperzine A features unique references to scientific papers and anecdotal reports.

What Is Huperzine A?

Huperzine A is a natural plant-based neuroprotectant that may enhance memory and boost overall cognition. An alkaloid compound derived from the Chinese club moss Huperzia serrata, huperzine A was first identified in the 1980s, but Chinese herbal medicine has been using extracts of the plant for centuries.

Though it’s typically used in the treatment of Alzheimer’s disease and other neurodegenerative disorders, huperzine A’s nootropic potential is making it increasingly popular with students and otherwise healthy individuals who want to think more clearly, learn more quickly, and recall more accurately.

Benefits and Effects of Huperzine A

Huperzine A offers benefits for both the brain and body.


Among the most important benefits of Huperzine A is its ability to protect the brain from oxidative damage, one of the most common problems associated with aging. Oxidative damage is at the heart of most age-related illnesses and is believed to play a major role in the development of Alzheimer’s disease and other neurological disorders.‍[1]

Oxidative damage starts with an abnormality that occurs when oxygen molecules split into individual atoms, a normal process that constantly happens in the body. Ideally, each atom should be surrounded by pairs of electrons that orbit the atom in layers, but as we get older, the process becomes less reliable, and an increasing percentage of new atoms are formed without a full complement of electrons. These imbalanced or unstable atoms, called free radicals, scavenge surrounding cells in search of electrons they can appropriate to balance their electron layer.

When free radicals attack nearby cells, they create a chain of potentially damaging chemical reactions and ultimately destabilize the cells from which they “borrow” electrons. This effect can be offset by the presence of antioxidants, or molecules that can “donate” an electron to a free radical without becoming unstable themselves. When free radicals and antioxidants are present in balance, the process can actually be beneficial, but when free radical activity outstrips antioxidant activity, the result is oxidative stress that damages lipids, proteins, and DNA.

Over time this damage can lead to several debilitating and even deadly age-related disorders, including diabetes, hypertension and heart disease, atherosclerosis or hardening of the arteries, cancer, and neurodegenerative diseases like Alzheimer’s and Parkinson’s.

Huperzine A is a potent antioxidant that has been shown to positively affect oxidative balance‍[2] and is considered a safe, effective, and well-tolerated adjunct treatment for Alzheimer’s disease.‍[3]

Memory Enhancer

Huperzine A can improve memory by improving brain levels of acetylcholine, an important neurotransmitter crucial to all aspects of cognition.‍[4] It has been shown to significantly inhibit the production of acetylcholinesterase, an enzyme that breaks down and degrades acetylcholine; this action effectively raises the levels of acetylcholine in the brain, which in turn enhances cognition in general and improves memory in particular.

While this benefit is of great importance in the treatment of Alzheimer’s disease,‍[5] clinical trials indicate that huperzine A can improve both memory and learning ability in healthy young people as well.‍[6]

Protects Against Glutamate Toxicity

Glutamate is a powerful excitatory neurotransmitter responsible for sending signals between nerve cells. It plays an important role in learning and memory when present at normal levels, but when concentrations are too high, it can become toxic and may lead to cell damage and even cell death. Chronic glutamate toxicity caused by oversensitive receptors is a typical feature of neurodegenerative diseases and causes anxiety, restlessness, increased sensitivity to pain, and a diminished ability to focus or concentrate. This syndrome is particularly dangerous to older people, as age appears to increase receptor sensitivity and make neurons more susceptible to glutamate toxicity.‍[7]

Huperzine A has been shown to act as an antagonist to glutamate receptors in the brain, preventing neurons from being overactivated by glutamate.‍[8] This action helps normalize glutamate levels and is considered valuable in the treatment of neurodegeneration.

Relieves Symptoms of Depression

A 2016 review of three clinical trials suggests that huperzine A supplementation may be effective in alleviating the cognitive impairment symptoms of major depressive disorders.‍[9] A total of 238 people aged 16 to 60 were involved in the trials, which compared the effectiveness of antidepressant treatment to treatment with antidepressant supplemented with huperzine A. While the addition of huperzine A did not appear to treat the depressive disorders, the group who took both antidepressants and huperzine A showed significantly greater improvement in both cognitive functioning and quality of life.

How It Works

Huperzine A is a water-soluble alkaloid that readily crosses the blood-brain barrier and rapidly distributes throughout all regions of the brain. In humans, it appears in the blood within 5–10 minutes, and peak concentration is achieved in about an hour. It has a half-life of about 10 hours and is mostly eliminated through urine within 24 hours.‍[10]

In the brain, huperzine A inhibits the production of the G4 isoform of acetylcholinesterase, an enzyme that degrades and diminishes the neurotransmitter acetylcholine levels. This action effectively raises acetylcholine levels, which is strongly associated with all aspects of cognition and has been shown to play a vital role in the formation of new memories. High acetylcholine levels also enhance brain signaling and improve the response time of cortical circuits, while simultaneously decreasing excitatory feedback that can impede memory retrieval.

Studies show that huperzine A has a potency equal to or even greater than prescription acetylcholinesterase inhibitors.‍[11]

Huperzine A has also been shown to act as a powerful antioxidant, neutralizing and, in some cases preventing or even reversing oxidative damage caused by free radicals in the brain. This antioxidant capability is considered key to huperzine A’s value as an adjunct therapy in the treatment of Alzheimer’s disease and other neurological disorders.

Huperzine A is also known to help protect the brain against glutamate toxicity by blocking certain types of glutamate receptors. This action keeps brain cells from being overactivated and helps normalize glutamate levels, preventing chronic glutamate toxicity typically associated with dementia and other age-related neurological disorders.


There is no medically recognized guideline for Huperzine A dosage, but in clinical research studies, it has been safely administered as follows: 50–200 mcg twice daily for the treatment of Alzheimer’s disease, 100 mcg twice daily to improve memory in adolescents, and 30 mcg twice daily to relieve senile or pre-senile dementia.‍[12]

It can be taken with or without food at any time of day.

Due to its long half-life of over 10 hours, cycling may be useful. A cycle of 2–4 weeks of supplementation followed by a break from supplementation is typical, though no optimal cycle length has been identified.


While huperzine A will have an effect on its own, stacking it with the right components may yield even better results.

Taking huperzine A in combination with a choline source such as Alpha GPC can increase the amount of acetylcholine in the brain, further enhancing the effect of huperzine A.

Many individuals lack sufficient choline in their diets, therefore supplementation may be beneficial.

A racetam is also a good choice for stacking with huperzine A. Racetams are thought to activate glutamate receptors that are located near acetylcholine receptors. This activity sensitizes the acetylcholine receptors, so they are more likely to become activated. Sensitizing the receptors with a racetam and increasing the amount of acetylcholine with huperzine A enhances the nootropic effect of both drugs.

Huperzine A is also often paired with Noopept, a powerful synthetic nootropic.

Memory Boosting Huperzine A Stack


As Needed / Cycled

Side Effects

Huperzine A appears to be safe and well tolerated when taken in moderation, though long-term safety or safety during pregnancy have not been studied. No incidence of toxicity has been documented in studies and trials on huperzine A. When taken in amounts commonly used for supplementation, side effects are infrequent and transitory and consist mainly of minor digestive upset.

When taken in large doses huperzine A can cause nausea, vomiting, diarrhea, slurred speech, muscle twitching, drooling, incontinence, elevated blood pressure, and a slow heart rate.

Huperzine A may interact with anticholinergic medications such as atropine and scopolamine; it may also interact with antihistamines and antidepressant medications.‍[13] Individuals who are taking these medicines or who have heart disease, hypertension, or are taking anticholinergic medications for Alzheimer’s or glaucoma should speak to their doctors before taking it.

Where to Buy

Huperzine A supplements are relatively easy to find wherever supplements are sold locally or can be purchased online. We recommended Double Wood Supplements Huperzine A tablets from Amazon.

Alternatively, you can order Huperzine A from a specialized nootropic vendor such as PureNootropics.net.

There are also nootropic supplements that contain Huperzine A as one of their active ingredients, such as Alpha Brain.

Closing Thoughts

Huperzine A is a natural supplement that acts as an antioxidant, neuroprotectant, and nootropic. Decades of research indicate that it may enhance memory and overall cognition, relieve the cognitive impairment symptoms of major depressive disorders, help treat neurodegenerative diseases, and even protect the brain from age-related oxidative damage. It’s safe, well-tolerated, and non-toxic when taken in moderation.

If you’re interested in a reliable, affordable nootropic that can boost your memory while it helps maintain optimal brain health, huperzine A may be a good addition to your stack.


Planning to start a new supplementation regimen? See our medical disclaimer.

This page was last updated on July 16, 2021.