Huperzine A Review: An All Natural Herb Supplement With Powerful Memory Benefits & Uses (AKACerebra, Selagine)

Updated September 10, 2018

What is Huperzine A?

Huperzine A (HupA), also known as L-Huperzine A, Selagine, and Cerebra, is a natural alkaloid compound used in traditional Chinese medicine that has gained popularity as a nootropic supplement. It is isolated from Huperzineserrata, a clubmoss that is also categorized as a Chinese herb.
This compound is commonly used as a drug for those suffering from neurodegenerative diseases, and as a nootropic supplement for those looking to enhance memory, energy, and focus. It is known to help boost brain health through its neuroprotective effects, and is even used by bodybuilders to improve energy and gains.
Not every supplement will contain HupA that is extracted from the plant – synthetic alternatives exist that are less expensive and appear to work equally well. (3) In fact, even the HupA that is extracted from the plant is highly purified and thus does not contain other plant compounds.
Once taken this herb is rapidly absorbed and easily crosses the blood-brain barrier. It is this ability to penetrate the blood-brain barrier that gives this nootropic its cognitive-boosting abilities.
Many users enjoy the cholinergic functions of this drug, which increases neuronal acetylcholine levels without heavily drawing on your choline stores.

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How Does Huperzine A Work

Huperzine A has been found to (2):

  • Reduce oxidative stress
  • Protects brain cells against apoptosis
  • Reduce beta-amyloid plaque (this plaque is tied to age-related cognitive decline and related neurological disorders)
  • Regulates the expression and regulation of nerve growth factor and its signalling
  • Increase neurotransmitter concentrations in the brain

It is believed to exhibit these neuroprotective benefits largely through acting as a reversible acetylcholinesterase (AChE) inhibitor. (1,2) It increases the levels of acetylcholine (ACh) in the brain through blocking cholinesterase, an enzyme responsible for the breakdown of ACh.
ACh is a neurotransmitter important for learning, memory, and focus. AChE inhibitors are the main drugs used to treat Alzheimer’s disease.
One study even found that supplementation with this herb increased norepinephrine and dopamine levels in the rat brain. (10)
It has also been shown to block the NMDA receptor ion channel, resulting in decreased glutamate toxicity. (4)
By increasing ACh, dopamine, and norepinephrine levels in the brain and suppressing excitatory glutamate, memory formation and retrieval is improved while protecting the brain from excitatory feedback.

Benefits & Uses


Many studies support the use of this supplement for improving learning and memory in both animals and humans with learning and memory difficulties. (2) Clinical trials have found improvements in the memory of elderly subjects, those with Alzheimer’s disease (AD), those with vascular dementia, and those with benign senescent forgetfulness. HupA is used as a drug for those suffering from AD in China.
One study examined the effects of HupA on memory function in junior middle school students following four weeks of supplementation with the supplement or a placebo. (5) This study found that those in the treatment group experienced benefits in learning performance and memory when compared to the placebo group.
Peak plasma concentrations have been found around one hour post-ingestion, so it is best to take this nootropic one hour before exams or related activities, when you are looking for the biggest memory boost.


Limited scientific evidence suggests that Huperzine A may be helpful for those suffering from depression. (1)
There have not been any high-quality human studies comparing monotherapy of this supplement with antidepressant drugs, however the little research that has been done demonstrated that adjunctive treatment led to resolution of some of the cognitive symptoms associated with major depressive disorder.
AChE inhibitors have been shown to help those with depression, so as an AChE inhibitor, it follows that this nootropic may be of benefit to those with depression.


Some use this nootropic to boost mental energy and alertness. This effect may be thanks to the boost in dopamine. Low levels of dopamine have been linked to chronic fatigue and lack of motivation.

Age-Related Cognitive Decline

While there have not been any long-term studies of this drug, it is likely that supplementation would help to prevent age-related cognitive decline thanks to its activity as a cholinesterase inhibitor, which is how it boosts neural ACh concentration. (6)


While studies are lacking on the effects of this specific drug on ADHD, insufficient ACh levels are one of the many pathologies of ADHD. (8) Low levels of dopamine and norepinephrine have also been tied to the pathogenesis of ADHD. The boost in ACh, dopamine, and norepinephrine caused by Huperzine A may lead to improvements in ADHD and possibly general focus and attention.


Similar to ADHD, there have not been studies examining the effect of Huperzine A on those with anxiety, however research suggests that there may be an impact of supplementation on the anxiety symptoms of those with depression. (1) One study found that anxiety scores were lower in humans treated with HupA in comparison to placebo, however this trend did not result in significance.
However, one reddit user reported increased anxiety when taking this drug, so the effect may vary from one user to the next.

May Protect Against Alcohol- and Drug-Induced Brain Damage

This supplement has been found to act as a neuroprotectant, which can help to protect the brain against damage caused by a wide array of sources. (7) This can include air pollution and even drug or alcohol use.

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In drugs of abuse, such as cocaine, cholinergic transmission is altered, and this is linked to psychostimulant reinforcement. (9)
In a unique study on addiction, participants were given either HupA or placebo and then given cocaine on days 1, 9, and 10. It was found that the participants who were given the treatment had lessened stimulation, high, drug effects, and attenuated bad effects and other addiction-related feelings and behaviours.
This study suggests that supplementation with this drug may help treat those with cocaine abuse disorders.

Dosage for Memory

The typical dosage of this supplement for memory in healthy people is 100 to 400 mcg taken either once daily or split into two doses.
HupA is water soluble, so you do not need to take it with food. This supplement is rapidly absorbed with peak plasma concentrations at around 70 minutes post ingestion, with a long half-life of 10-14 hours.
In order to avoid tolerance or habituation, many will cycle this nootropic. Cycling HupA will help to avoid side effects and improve efficacy. There is not much scientific backing regarding the best cycling schedule, however many will take this herb for 2-4 weeks followed by a break of around one week.
While this nootropic is not a stimulant, most users will take one or two doses early in the day rather than before bed. This is to benefit cognition and learning when you really need it, rather than just before sleep.

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Stacking Huperzine A

Huperzine A stacks well with other cholinergic nootropics, including members of the racetam family and high-bioavailable choline supplements, including Alpha GPC, Citicoline (CDP-Choline), and Centrophenoxine. Stacking these nootropics together can lead to further benefits in memory, learning, and focus.
Another powerful memory stack is HupA, Noopept, and a choline source.
Recommended Stack:

  • 20 mg/day Noopept
  • 500 mg/day Citicoline
  • 200 mcg Huperzine A, cycled

Side Effects

This supplement is considered safe with a low toxicity profile when used within recommended dosages (2). The majority of the side effects found in clinical trials are similar to those of other cholinergic compounds, including:

  • Headache
  • Dizziness
  • Nausea
  • Digestive upset
  • Lowered heart rate

Other users have reported abnormal dreams, which may be a side effect of the boost in memory function as these areas of your brain may be working overtime, even during sleeping hours.

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Safety and Interactions

Huperzine A is considered safe when taken at recommended dosages for 3 months at a time. If you want to take this drug for longer, it is recommended to cycle it on and off. this drug.
If you have certain conditions, taking this supplement may not be safe. These include:

  • Epilepsy
  • Slow heart rate
  • GI tract blockage
  • Asthma or other lung conditions
  • Peptic ulcers

There is not sufficient evidence for the safety of this supplement in women who are pregnant or breastfeeding.
Huperzine A does interact with certain drugs, including anticholinergic drugs, cholinergic drugs, and AChE inhibitors. These drugs are common for those with Alzheimer’s disease, glaucoma, and depression.

User Reviews

“I’m feeling wide awake and everything is much more “clear” than normally. This is quite different from the one you get using stimulants. It feels as if somebody had upped the contrast on reality.” LongeCity user review
“20mcg 1% powder very effective and has been over the past year 1-2x/wk with centrophenoxine. I used to take just Hup w/o centro, but it takes awhile to “kick in”, so I added centro. Long, steady, consistent duration. Little bit of an edgy feeling, but not enough to bother. How I know it works is because without realizing it, I’m locked into a task and more fluid thought/word formation.” Reddit user review

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Where to Buy

While you may find this nootropic at local pharmacies, it is not widely available in stores. It is best to purchase through online supplement vendors. We recommend Nootropics Depot or Pure Nootropics for online vendors thanks to the quality of supplements offered. You will also find HupA capsules on Amazon.
Another option if you are looking for a well-rounded nootropic blend that already contains HupA is Alpha Brain, which you can find through here.

Concluding Thoughts

Huperzine A provides a subtle improvement in memory, concentration, and for some, mood. This can be of benefit for both short- and long-term memory.
If you are looking for more of a noticeable or immediate effect, it stacks well with more powerful nootropics of the racetam family.


  1. Huperzine A for treatment of cognitive impairment in major depressive disorder…
  2. Neuroprotective effects of Huperzine A: a natural cholinesterase inhibitor…
  3. In vitro production of huperzine A, a promising drug…
  4. The NMDA receptor ion channel: a site for binding on huperzine A
  5. Huperzine-A capsules enhance memory and learning performance in 34 pairs of matched adolescent students
  6. Huperzine A for Alzheimer’s Disease…
  7. Huperzine A, a potential therapeutic agent for dementia, reduces neuronal cell death caused by glutamate
  8. Choline transporter gene variation is associated with ADHD
  9. Safety and preliminary efficacy of the ACh inhibitor HupA as a treatment for cocaine use disorder
  10. Second generation cholinesterase inhibitors: effect of HupA on cortical biogenic amines

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