Can Huperzine A Really Prevent Alzheimer’s?

A supplement called huperzine A, used for centuries in traditional Chinese medicine, has been an approved therapy in China to treat Alzheimer’s disease since 1994. In the United States, the U.S. Food and Drug Administration classifies huperzine A as a dietary supplement. It is sold over the counter in stores and online. However, there is no firm evidence that adults concerned about brain health should take the supplement.

Laboratory studies have suggested that huperzine A may be anti-inflammatory (inflammation can contribute to memory and thinking problems), and it may work like an antioxidant, which can help the brain function. Some lab studies have even suggested it may increase the levels of some neurotransmitters, which act as chemical messengers in the brain. But those studies were not in people.

Clinical trials of people with Alzheimer’s disease in China have suggested that huperzine A can improve memory, thinking skills and the ability to complete the typical tasks of daily life. But a 2025 research review in the Beni-Suef University Journal of Basic and Applied Sciences found that existing clinical study results on the supplement’s effects, including a U.S. trial reported in 2011 in Neurology, were inconclusive. Many studies were too small, short-term and lacking in solid evidence. More large, longer-term, controlled studies are needed to establish whether huperzine A is safe and effective, the reviewers wrote.

Importantly, no clinical study has tested whether the supplement can prevent Alzheimer’s, though one lab experiment suggested how it might: In a 2024 study published in the journal Biology, huperzine A — when applied to brain cells in a petri dish — lowered levels of the amyloid beta protein, which accumulates in Alzheimer’s disease. But again, the experiment was not done in humans.

AARP’s Global Council on Brain Health (GCBH), an independent collaborative of scientists, health care providers, scholars and other experts, reviewed the evidence for possible brain benefits of huperzine A and published the findings in its 2019 report, “The Real Deal on Brain Health Supplements.”

The GCBH does not recommend taking the supplement for brain health. Per the report, studies of the supplement in humans have not provided enough evidence that it could prevent dementia or Alzheimer’s disease, improve memory or protect the brains of older adults.

Importantly, huperzine A may cause side effects such as dizziness, nausea and stomach problems. It may also cause side effects when taken with other medications, including prescription drugs for Alzheimer’s, such as Aricept. Talk to a health care professional if you are considering taking it.