Huperzine A, sometimes called selagine, is an alkaloid compound that is purified from the Chinese club moss Huperzia serrata. It was first identified in the 1980s, but extracts of the plant have been used in China for centuries as an herbal medicine. Huperzine A is commonly used to treat Alzheimer’s disease and other neurodegenerative diseases for its ability to improve memory and cognitive abilities while acting as a neuroprotectant. Huperzine A is commonly taken as a natural supplement in healthy individuals for its nootropic effects.

Benefits and Effects

Huperzine A can be used as a memory enhancer. It is particularly effective when taken while studying for a test or when trying to learn any new material. It can also be taken regularly to help protect against age-related declines in memory.

Most clinical studies of huperzine A have focused on its use as a treatment for Alzheimer’s disease. A systematic review of 20 randomized controlled trials concluded that huperzine A appears to have beneficial effects on improvement of cognitive function, daily living activity, and global clinical assessment in participants with Alzheimer’s disease.[1] None of the trials followed the patients for longer than 16 weeks to see if huperzine A could slow the progression of the disease, but other cholinesterase inhibitors have been found to slow the progression of neurodegenerative diseases.

Huperzine A has also been formally studied as a memory enhancer for students.[2] The students were given a memory test, and then they were given either huperzine A or a placebo. Four weeks later, they were retested. They also took exams in language and mathematics covering the lessons received at school during the four-week time period. Huperzine A was found to significantly enhance memory. It did not, however, improve understanding of mathematics. It just improved the students’ ability to retain and recall facts. The students taking huperzine A had significantly improved scores on their language tests compared to the students taking a placebo.

How it Works

Huperzine A increases levels of acetylcholine in the brain by blocking the action of cholinesterase. Huperzine A also has some activity as an NMDA receptor antagonist. It is neuroprotective, shown to protect neurons from damage due to glutamate, peroxides, and beta-amyloids. In mouse studies, it has been shown to promote neurogenesis.[3]

Four of the five drugs approved by the FDA for treating Alzheimer’s disease are cholinesterase inhibitors. Acetylcholine has been shown to play a vital role in the formation of new memories. High acetylcholine levels enhance the magnitude of neurotransmissions to the cortex. It also suppresses the release of glutamate, which in turn suppresses feedback excitation of the cortex. The net effect is to make cortical circuits able to quickly respond to relevant sensory input, while simultaneously decreasing excitatory feedback that can impede memory retrieval.

The cholinesterase inhibitors currently on the market for treating Alzheimer’s disease are fairly effective in improving memory in these patients. These drugs may also act to slow disease progression through their neuroprotective effects.[4] However, the use of the four FDA-approved drugs is limited by their severe side effects on the digestive tract, lungs, and muscles. Acetylcholine is used in many parts of the body other than the brain, and increasing acetylcholine throughout the body causes many disturbances. Huperzine A doesn’t have this limitation because it appears to have a very strong affinity for brain cholinesterases only.


For improving memory in young people, huperzine A can be taken at 100 mcg twice a day. It has been used at 50 to 200 mcg twice a day to treat Alzheimer’s disease. We suggest that regular users take a break from the drug every few weeks to avoid physical habituation. For example, after taking huperzine A daily for three weeks, consider cycling off of it for one week before resuming regular use.

Huperzine A does not need to be taken with food. It is quickly absorbed into the body and will begin to enhance memory immediately. It has a very long half-life in the body, and a single dose will provide benefits for over 24 hours. The drug has been shown to be quite capable of passing the blood-brain barrier after oral ingestion and quickly accumulates in the cerebrospinal fluid.


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 can be effective.

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 and popular nootropic.

Memory Boosting Huperzine A Stack


As Needed / Cycled

Side Effects

Huperzine A appears to be quite safe even when taken daily however it tends to be used non-daily as necessary or cycled in order to avoid tolerance.

Longer-term safety has not been studied. Occasionally, huperzine A can cause digestive upset such as nausea, vomiting, and diarrhea. If taken in excessively large doses it can cause slurred speech, muscle twitching, drooling, incontinence, elevated blood pressure, and a slow heart rate.

Because huperzine A can slow the heart down and affect blood pressure, individuals with heart disease should use it cautiously. Its safety during pregnancy is unknown.

Individuals taking anticholinergic medications for Alzheimer’s or glaucoma should discuss huperzine A with their doctor 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 Source Naturals Huperzine A tablets from Amazon.

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

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

Closing Thoughts

Huperzine A is an excellent nootropic for a short-term boost in memory as well as promoting long-term memory abilities. It has a noticeable impact on the ability to memorize and recall facts. It will not, however, turn anyone into a genius overnight. It just makes studying more effective as well as improving the ability to recall what you’ve learned.

Huperzine A may even help protect the brain from age-related damage as it enhances memory.

Huperzine A is an effective natural nootropic to consider supplementing on its own or part of your stack.

References   [ + ]

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