Lithium and Alzheimer's: What the Research Shows So Far

A 2025 study in Nature found that lithium levels were lower in the brains of people with early memory loss, and a low-dose lithium salt reversed memory loss in mice. Here's what that research means, what it doesn't, and why you shouldn't start lithium supplements on your own.

By Jim Pavlish, Editor · Last updated: October 28, 2026 · Editorial policy

Lithium is best known as a prescription medicine for bipolar disorder. It's also a natural trace element found in small amounts in food and drinking water. In 2025, a major study suggested that the brain's own lithium may help protect memory, and that losing it could be one of the earliest steps toward Alzheimer's disease. The headlines were exciting. Here's what was actually found, and what it means for you right now.

This page is general information, not medical advice. Don't start, stop or change any medicine or supplement without talking to your doctor.

What the 2025 study found

A team led by Dr. Bruce Yankner at Harvard Medical School published the study in the journal Nature in August 2025. It was funded in part by the National Institutes of Health. The research had several parts:

In human brains. The team measured a range of metals in donated brain tissue from people with normal memory, mild cognitive impairment (MCI) and Alzheimer's. Lithium was the only metal that was clearly lower in the brains of people with MCI, an early stage that often comes before Alzheimer's. In people with Alzheimer's, the researchers found that amyloid plaques (the sticky protein clumps typical of the disease, see Amyloid and Tau Explained) seemed to trap lithium, leaving even less available to brain cells.

In mice. When the researchers cut the lithium in the diet of mice by about half, the mice developed more amyloid plaques and tau buildup, more inflammation, loss of connections between nerve cells, and faster memory decline. This happened both in mice bred to develop Alzheimer-like changes and in normal aging mice.

A different form of lithium. The usual prescription form, lithium carbonate, tended to get stuck to amyloid plaques. The team tested 16 lithium salts and settled on one called lithium orotate, which binds less to amyloid. Given to mice at very low doses in their drinking water, lithium orotate reduced plaques and tangles, restored nerve connections and reversed memory loss. Lithium carbonate at the same low dose had little effect. The mice showed no signs of toxicity over long-term treatment.

Earlier clues

This wasn't the first hint of a link. A large Danish study published in JAMA Psychiatry in 2017 compared dementia rates with the natural lithium levels in local drinking water across Denmark. People in areas with the highest levels (above 15 micrograms per liter) had about 17% lower dementia rates than those with the lowest levels. But the pattern wasn't simple: some middle levels were linked to higher risk. Because it was an observational study, it couldn't rule out other differences between regions, and the authors did not recommend adding lithium to water. Some smaller studies in people taking prescription lithium for mood disorders have also hinted at lower dementia rates, but results have been mixed.

What this research does not show

It's easy to read "lithium reversed Alzheimer's" and assume a cure is around the corner. Some important cautions:

• Mice are not people. Many treatments that worked in mouse models of Alzheimer's have failed in human trials.
• The human evidence is about brain levels, not treatment. The study found lower lithium in brains of people with MCI and Alzheimer's. It did not test whether giving people lithium prevents or slows the disease.
• The right dose is unknown. Dr. Yankner himself said that before recommending lithium orotate, "we need to determine the effective and safe dose range in people."
• Water studies show links, not proof. Places with more lithium in the water may differ in many other ways.

Is lithium safe to take on your own?

No one should start taking lithium for memory without a doctor. At the doses used for bipolar disorder, lithium is a powerful drug that needs regular blood tests, because the gap between a helpful and a harmful level is small. According to MedlinePlus, too much lithium can cause shakiness, confusion, vomiting, unsteadiness and other serious problems, and long-term use can affect the kidneys and thyroid. Older adults, people with kidney problems and people who take certain blood pressure drugs, water pills or anti-inflammatory painkillers such as ibuprofen are more at risk of lithium building up.

Lithium orotate is sold online as a supplement. Supplements aren't reviewed by the FDA for safety or effectiveness before they're sold, and the doses that worked in mice don't translate simply to people. See our guide to supplements for memory for how to judge these products.

If you or a family member already takes prescription lithium, don't stop it because of this news, and don't add an over-the-counter version on top. Bring any questions to the prescriber.

What happens next

The key question now is whether low-dose lithium is safe and reaches the brain in people. A small trial called LiO-AD, led by Johns Hopkins University with NIH support, is listed on ClinicalTrials.gov as planned to start in late 2026. It is designed to test lithium orotate versus a placebo for 9 weeks in adults with early, biomarker-confirmed Alzheimer's, mainly looking at safety and whether lithium levels in the spinal fluid rise. It is an early-stage study, so it won't answer whether lithium slows memory loss. Larger trials would be needed for that.

If you're interested in helping answer questions like this, our guide to Joining a Clinical Trial explains how to find and judge a study.

The bottom line

The 2025 lithium research is a genuinely new idea about how Alzheimer's might start, and it's being taken seriously. But it is early science, mostly in mice, and it is not a reason to take lithium. For now, the best-supported steps for brain health are the ones in Reducing Dementia Risk: The 14 Risk Factors: managing blood pressure, staying active, treating hearing loss and staying socially connected. For tips on reading headlines like this one, see How to Read Health Research News.

Sources

1. Nature (Aron et al., 2025): Lithium deficiency and the onset of Alzheimer's disease
2. National Institutes of Health: Lithium levels tied to Alzheimer's disease and dementia (NIH Research Matters, Sept 2025)
3. JAMA Psychiatry (Kessing et al., 2017): Association of Lithium in Drinking Water With the Incidence of Dementia
4. ClinicalTrials.gov: LiO-AD: Lithium Orotate in Alzheimer's Disease (NCT07459959)
5. MedlinePlus (U.S. National Library of Medicine): Lithium

Not medical advice. This article is general information, not a diagnosis or treatment plan for any individual. Talk with a doctor about your situation.

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