Ingredient profile
Huperzine A in MemoPryl: How It Works, Side Effects and Interactions
Huperzine A is a plant compound that works much like prescription Alzheimer's drugs. Only the eBay seller lists it for MemoPryl, not the brand graphics. Small dementia trials used 200 to 400 mcg a day, a study of healthy adults found no benefit, and it may slow the heart and worsen some epilepsy (ADDF, Huperzine A).
Written by the MemoPryl editorial teamUpdated
The basics
What is huperzine A?
Huperzine A is a compound taken from firmoss, a moss-like plant in the Huperzia family. Its action resembles that of most prescription Alzheimer's drugs (ADDF, Huperzine A).
Those drugs, such as donepezil, slow an enzyme that breaks down acetylcholine, a chemical nerve cells use to signal each other. Huperzine A acts on the same enzyme. That makes it closer to a medicine than most herbs in a memory supplement, and it is why its cautions look like drug cautions.
| Label name | Huperzine-A (eBay listing only) |
|---|---|
| Scientific name | From firmoss (Huperzia) |
| What it is | Plant alkaloid |
| Position in the list | 8 of 8 (no Supplement Facts panel with amounts was available to us) |
| Per serving | Not shown; listed by the eBay seller |
| Amount used in research | 200-400 mcg a day in small dementia trials |
| Strength of evidence | Small, high-bias trials |
| Traditional or marketed use | Works much like prescription Alzheimer's drugs |
| Main caution | May slow heart rate and worsen some epilepsy; adds to donepezil-type drugs. |
Which bottle?
Is huperzine A in every MemoPryl bottle?
We do not know. It is listed only by the eBay seller, not on the brand graphics.
Six names appear on the brand graphics. The eBay item specifics add two more: alpha-GPC and huperzine-A, both under "other ingredients" (eBay listing, MemoPryl). Two label versions exist, a 60-capsule NutraVibe bottle and a 30-capsule "Cognitive Support Formula" bottle.
No image we have shows a back panel for either one. So the extra two could be in one version, both, or neither. That uncertainty matters more for huperzine A than for any other name on the list.
- Ask the seller which version contains huperzine A
- Ask for a photo of that version's Supplement Facts panel
- Check the back panel of the bottle you receive
- Compare it with the two label versions
Read this first
Why does huperzine A act like a prescription drug?
Huperzine A works much like the drugs doctors prescribe for Alzheimer's. Taking both may make the side effects worse (ADDF, Huperzine A). Treat it as you would a medicine: tell your doctor and pharmacist you take it.
The evidence
Does huperzine A work for memory?
In dementia, the trials are small, short and at high risk of bias. In healthy adults, a study found no benefit.
| Group studied | Dose | What was found |
|---|---|---|
| People with dementia | 200 to 400 mcg a day | Some benefit, but trials were small, short and at high risk of bias |
| Healthy adults | Not stated in our source | No benefit in a study of 84 healthy military personnel |
| Prevention | None | No studies on preventing memory decline |
| MemoPryl formula | Not published | No trial |
"High risk of bias" means the way a trial was run could tilt its results. Small numbers and short follow-up make that worse. So even the dementia results are uncertain. For someone with everyday forgetfulness, the one healthy-adult study is the closest match, and it found nothing.
Mcg means micrograms, a thousandth of a milligram. A dose of 200 mcg is 0.2 mg, far smaller than the gram doses used for acetyl-L-carnitine.
Side effects
What are the side effects of huperzine A?
Headache, dizziness, blurred vision and stomach effects are reported. It might also lower heart rate (ADDF, Huperzine A).
Head and eyes
Headache, dizziness and blurred vision. Avoid driving if you feel dizzy.
Stomach
Stomach upset and related digestive effects. These are also typical of the prescription drugs it resembles.
Heart rate and seizures
It might lower heart rate and might worsen some types of epilepsy.
Ask your doctor before any product that may contain huperzine A. Stop and get care if you feel faint or your heartbeat feels unusually slow.
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Does huperzine A interact with any medications?
Yes. It may worsen side effects of donepezil-type drugs and may weaken anticholinergic drugs (ADDF, Huperzine A).
| Medicine | Examples | What can happen |
|---|---|---|
| Donepezil-type dementia drugs | Donepezil, rivastigmine, galantamine | Side effects may get worse |
| Anticholinergic drugs | Some bladder, allergy and stomach-cramp medicines | The medicine may work less well |
| Seizure medicine | Any | Huperzine A might worsen some epilepsy; St. John's wort can weaken phenytoin and carbamazepine |
| Other prescriptions | Birth control, warfarin, statins and more | St. John's wort in MemoPryl can weaken them |
Keep taking your prescribed medicine. Bring the bottle to your pharmacist, and read the full St. John's wort interaction list.
Long-term use
Is huperzine A safe to take every day?
Nobody can say for the long term. The trials were short, and there are no prevention studies that followed people for years (ADDF, Huperzine A).
Short dementia trials used daily doses. They do not tell you what happens after a year or more, or in people who take other medicines. Bacopa in the same formula also calls for care with dementia drugs, so the two may add together.
Check yourself in 20 seconds below. Question 4 covers huperzine A directly.
All ingredients
What should you ask before taking MemoPryl with huperzine A?
Which version has it?
Ask the seller whether your bottle, 30 or 60 capsules, lists huperzine A.
How much is in it?
Ask for the microgram figure. Without it, nobody can compare it with the trial doses.
Is it safe with my medicines?
Ask your pharmacist, with the bottle in hand.
Compare huperzine A with the other ingredients below, or see all eight on the ingredient overview.
FAQ
Huperzine A questions
Is huperzine A safe?
It carries real cautions. Huperzine A works like prescription Alzheimer's drugs, might lower heart rate and might worsen some epilepsy (ADDF, Huperzine A). Headache, dizziness, blurred vision and stomach effects are reported. Ask a doctor first if you have a heart condition, epilepsy or take a dementia drug.
Can you take huperzine A every day?
Short trials gave it daily, but no long-term or prevention studies exist (ADDF, Huperzine A). That leaves daily use over months or years unstudied. If your MemoPryl bottle lists huperzine A, follow the serving printed on it and talk with your doctor about longer use.
Can I take huperzine A with donepezil?
Not without your doctor's approval. Huperzine A may make the side effects of donepezil-type drugs worse, because both act on the same enzyme (ADDF, Huperzine A). Keep taking your prescribed medicine and ask the prescriber before adding MemoPryl.
Does huperzine A affect heart rate or blood pressure?
It might lower heart rate, according to the ADDF review (ADDF, Huperzine A). Our source does not report a blood pressure effect. If you take a medicine that slows the heart or you faint easily, ask a doctor before any product that lists huperzine A.
Does huperzine A work for healthy people?
The evidence says probably not. When 84 healthy military personnel took it in a study, they showed no benefit (ADDF, Huperzine A). The positive results come from small, short dementia trials at high risk of bias, at 200 to 400 mcg a day.
Which MemoPryl bottle has huperzine A?
Nobody has confirmed it. The eBay seller lists huperzine A, but the brand graphics do not. It could be in the 30-capsule version, the 60-capsule version, both or neither. Ask the seller before ordering, and check the back panel of the bottle you receive.
What is huperzine A made from?
It comes from firmoss, a moss-like plant from the Huperzia group (ADDF, Huperzine A). Despite the plant source, it behaves much like a drug, so treat it with the same care as a prescription medicine.
Who wrote this
Written and reviewed by
Plain-language pages built from the label, the sales page and linked public health sources.
Last updated . Read our editorial standards and how we check reviews. This website is run by a U.S. stocking partner that sells MemoPryl, not by the maker (the pack shots say "By NutraVibe"). We earn money when you buy through our order links.
Keep reading
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Side effects
Every reported side effect and drug interaction for MemoPryl's eight named ingredients, with when to stop and when to call 911.
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MemoPryl label versions
Version A vs version B, the eBay seller's two extra ingredients, and other products sold under the MemoPryl name.
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Bacopa monnieri (brahmi)
Bacopa, also called brahmi: small memory effects after about 3 months at 300 mg a day in trials.
Read moreU.S. stocking partner for MemoPryl
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