Huperzine A: Uses, Benefits, & More
A Nootropic Supplement May Support Brain Health
Verywell / Anastasia Tretiak
Medically reviewed by Arno Kroner, DAOM, LAc
Huperzine A is a chemical found in Chinese club moss. The scientific name of this club moss is Huperzia serrata (H. serrata). Huperzine A is used in traditional Chinese medicine.
Huperzine A is a natural version of an acetylcholinesterase inhibitor. Acetylcholinesterase is a protein that breaks down a naturally-occurring brain chemical called acetylcholine (ACH). So, by blocking acetylcholinesterase, huperzine A is thought to increase ACH levels, which tend to be low in people with Alzheimer's (AD). This is how Aricept (donepezil) also works as a treatment option for AD.
So, huperzine A may have potential nootropic effects. This means that huperzine A might support brain health, such as memory. And it is an approved medication in some countries, such as China. But the Food and Drug Administration (FDA) hasn't approved huperzine A as a prescription product yet.
This article will cover more on what you should know about huperzine A—its potential uses, side effects, and interactions.
Dietary supplements are not regulated like drugs in the United States, meaning the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. When possible, choose a supplement tested by a trusted third party, such as USP, ConsumerLab, or NSF. However, even if supplements are third-party tested, that doesn't mean they are necessarily safe for all or effective in general. Therefore, it is important to talk to a healthcare provider about any supplements you plan to take and check in about potential interactions with other supplements or medications.
Active ingredients (s): Huperzine A
Alternative name(s): Huperzine A, HupA, Chinese club moss, Huperzia serrata (H. serrata) extract, Qian Ceng Ta
Legal status: While huperzine A is marketed as a dietary supplement in the United States, its full legality is unclear.
Suggested dose: May vary based on the specific dosage form and medical condition
Safety considerations: Side effects and medication interactions are possible. There are also considerations regarding its use in children, pregnant people, and breastfeeding parents.
Uses of Huperzine A
Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.
Like many natural products, more extensive research is necessary. But people might use huperzine A for various reasons.
Alzheimer's Disease
In a systematic review and meta-analysis, there was a review and analysis on a collection of studies for huperzine A's potential use in people with Alzheimer's disease (AD).
There was also another review on a collection of studies for huperzine's potential use for AD in a systematic review.
In general, results from both of these articles suggest that huperzine A might help people with AD with the following improvements:
Brain function
Ability to do more things—like eating or getting dressed—on own for a longer period of time
Healthcare provider's overall impression of how an individual with AD is generally doing over time
In addition to these two articles, there is also a meta-analysis on huperzine A for AD in Evidence-Based Complementary and Alternative Medicine. And results seem to also support huperzine A. Huperzine A may help people with AD perform better on a brain function exam—in addition to being better at doing activities of daily living (ADLs), such as eating and getting dressed.
While these results are positive, extensive and high-quality research with larger and longer-term studies is still necessary to better assess huperzine A's effects and safety in people with AD.
Vascular Dementia
People with vascular dementia (VD) have medical conditions that affect the blood vessels in the brain. And these medical conditions may result in memory problems. People with VD may also experience changes in thinking and behavior.
A systematic review (a review of a collection of studies) of huperzine A's potential use for VD was conducted. Many studies did not meet specific quality measures (criteria) to make the cut—only one small clinical trial did.
And based on this one study, huperzine A didn't do better than placebo (a substance with no medicine) in terms of improving scores on a brain function exam. But after six months, huperzine A did seem to help people with VD on ADLs.
Since the results of this small study were mixed, no firm conclusion can be made about huperzine A for VD. Additional well-designed clinical trials are still necessary to evaluate huperzine A's effects better.
And with more studies, the meta-analysis article in Evidence-Based Complementary and Alternative Medicine was able to analyze a collection of studies for AD and VD. And in this meta-analysis article, results suggest that huperzine A may benefit people with VD.
In addition to doing better on ADLs, people with VD also improved on a brain function exam—moreover, people with VD experienced fewer side effects from huperzine A than those with AD.
Although the results from the meta-analysis were positive, additional high-quality clinical trials with a larger group of study participants are still necessary to evaluate huperzine A effects.
What Are the Side Effects of Huperzine A?
Like many medications and natural products, side effects are possible with huperzine A.
Common Side Effects
Most side effects have been mild and temporary.
Common side effects may include:
Severe Side Effects
In general, there is little information on the safety of huperzine A. But in a systematic review and meta-analysis, there were no reports of severe side effects.
The systematic review also echoed this, stating that side effects were mild with no severe side effects. Another meta-analysis also reported only mild side effects.
A severe allergic reaction, however, is a serious side effect that's still possible with any medication. If you're having a severe allergic reaction to huperzine A, symptoms may include breathing difficulties, itchiness, and rash.
Call 911 and get medical help immediately if you're having a severe allergic reaction or any of your symptoms feel life-threatening.
Precautions
A healthcare provider may advise against using huperzine A if any of the following applies to you:
Severe allergic reaction: If you have a severe allergic reaction to huperzine A or its components (ingredients or parts), you shouldn't take this medication.
Pregnancy and breastfeeding: There are likely no huperzine A product labels that target pregnant or breastfeeding parents. Moreover, there is little information about the effects and safety of huperzine A while pregnant or breastfeeding. But in rat and rabbit animal studies, taking Aricept (donepezil) late in pregnancy was linked to negative effects on the unborn fetus.
For these reasons, contact a healthcare provider to discuss the benefits and risks before taking huperzine A.
Children: Most huperzine A product labels target adults—not infants or children. Talk with a healthcare provider if you're considering huperzine A for your child.
Older adults over 65: While older adults participated in some huperzine A-related clinical trials, additional extensive research is still necessary. Moreover, some older adults may have a higher likelihood of medication side effects. For this reason, take huperzine A with caution.
Low weight: People under 121 pounds are more likely to experience side effects with Aricept, a human-made version of huperzine A. People with low weight might also have a higher likelihood of problems with huperzine A.
Dosage: How Much Should I Take Huperzine A?
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.
While there are some studies on huperzine A in humans, more high-quality clinical trials are still necessary. For this reason, there are no guidelines on the appropriate dosage to take huperzine A for any condition.
In clinical trials for Alzheimer's disease (AD), however, the total daily dose (TDD) range was 0.2-0.8 milligrams (mg). As for vascular dementia (VD), the TDD range was 0.1-0.3 milligrams. Generally, a dosage of 0.4 milligrams twice daily for up to 24 weeks was well-tolerated.
More consistent and reliable information is still necessary. So, follow a healthcare provider's recommendations or label instructions before choosing a dose for huperzine A.
What Happens If I Take Too Much Huperzine A?
There is little information about huperzine A safety, toxicity, and overdoses in humans. But symptoms of overdoses with huperzine A are likely similar to its potential common and serious side effects—but excessive and severe. And since some huperzine A products might be contaminated with prohibited ingredients, health risks from these substances are also possible.
If you suspect you're experiencing life-threatening side effects, seek immediate medical attention.
Interactions
There is limited information about safety and possible medication interactions with huperzine A. Most of the current data is based on huperzine A's potential uses.
Alzheimer's disease (AD) medications: Huperzine A may work similarly to Aricept (donepezil), an AD medication. For this reason, huperzine A may have additive effects with AD medications, raising the risk of side effects.
Anticholinergic medications: Acetylcholine (ACH) is a naturally occurring substance in your body. In people with AD, there is a low level of ACH.
Anticholinergic medications—like Ditropan XL (oxybutynin) for overactive bladder (OAB)—might worsen this problem and work against AD medications. Since huperzine A may improve AD symptoms by increasing ACH, anticholinergic medications might also work against huperzine A.
It is essential to carefully read a supplement's ingredients list and nutrition facts panel to learn which ingredients are present and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.
Verywell / Anastasia Tretiak
How to Store Huperzine A
Since storage instructions may vary for different natural products, carefully read the directions and packaging label on the container. Keep your medications tightly closed and out of the reach and sight of children and pets, ideally locked in a cabinet or closet. Generally, most medicines' optimal storage condition is in a cool and dry place.
Discard after one year or as indicated on the packaging. Avoid putting unused and expired medicines down the drain or in the toilet. Visit the FDA's website to know where and how to discard all unused and expired medicines. You can also find disposal boxes in your area.
Ask a pharmacist or healthcare provider any questions about how to dispose of your medications or supplements.
Similar Supplements
Huperzine A may have potential uses for memory and brain function. So, other potentially similar supplements may include:
Specific vitamins: According to the National Center for Complementary and Integrative Health (NCCIH), people with Alzheimer's disease (AD) might benefit from vitamin E. Vitamin E might allow people with AD to do more things on their own for a longer period. And long-term use of specific B vitamins may slow down worsening memory problems in older adults. These B vitamins may include pyridoxine (vitamin B6), folic acid (vitamin B9), and cyanocobalamin (vitamin B12).
Omega-3 fatty acids: Based on available data, omega-3 fatty acids from eating more fish may prevent worsening memory problems in older adults.
Don't combine multiple natural products until you first talk with a healthcare provider or pharmacist. Checking in can help you avoid possible interactions and side effects and ensure you're giving these supplements a fair trial at appropriate doses.
Frequently Asked Questions
What is the most common dosage form of huperzine A?
Huperzine A is available in a few different dosage forms—with capsules potentially being the most common.
Are there huperzine A products from manufacturers in the United States?
Yes. There are huperzine A products made by manufacturers in the United States.
Remember also to check the huperzine A product label to ensure that it was tested by a trusted third party, such as USP, ConsumerLab, or NSF. Buying products tested by a trusted third party can reduce your risk of exposure to prohibited ingredients that might harm your health.
Will huperzine A improve my workout?
Huperzine A is a common ingredient in pre-supplement workouts. This is because it's thought to improve brain or mental function, which may reduce your perceived sense of exertion (effort) and enhance exercise performance. But based on a small clinical trial, huperzine A doesn't seem to improve brain or mental function.
Is it okay to take huperzine A every day?
This is uncertain. According to a 2013 article, people with Alzheimer's disease (AD) can likely tolerate 0.4 milligrams (mg) of huperzine A by mouth twice daily for up to 24 weeks. But in general, there's limited information about huperzine A's safety—especially with long-term use for more than 24 weeks.
How do I take huperzine A safely?
In general, to take natural products—like huperzine A—safely, inform a healthcare provider and pharmacist about any medication changes. This includes over-the-counter (OTC), herbal, natural medications, and supplements.
They can help prevent possible interactions and side effects. They can also ensure you’re giving huperzine A a good trial at appropriate doses.
Sources of Huperzine A & What to Look For
There are a few sources of huperzine A.
Food Sources of Huperzine A
Huperzine A is naturally found in Chinese club moss, but there is little information about huperzine A food sources.
Huperzine A Supplements
Huperzine A is available in several forms, including capsules and tablets. If you have difficulties swallowing pills, huperzine A may also be available in liquid and powder dosage forms.
Vegetarian and vegan options might also be available. You may also see huperzine A in combination with other ingredients.
Your specific product will depend on your preference and what you hope to get in terms of effects. Each product may work a bit differently, depending on the form. So, following a healthcare provider's recommendations or label directions is essential.
Summary
Huperzine A is a substance found in Chinese club moss. It's used in traditional Chinese medicine. It might be potentially used for brain health, especially in people with Alzheimer's disease (AD) or vascular dementia (VD). But similar to many medications and natural products, side effects and medication interactions are possible. It's also important not to delay the diagnosis and treatment of AD.
Additional higher-quality clinical trials are still necessary to better assess the effectiveness and safety of huperzine A. Before taking huperzine A, involve a pharmacist or healthcare provider to help you safely achieve your health goals.
