THC Could Protect Against Alzheimer’s When Combined with This Common Medication

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“Pothead” might take on a whole new meaning.

A recent study suggests that low doses of THC, the primary psychoactive compound in cannabis, could help protect memory and reduce Alzheimer’s-related brain damage—but only when paired with a common anti-inflammatory medication.

Although the research was conducted in mice, scientists note that because both substances are already widely used, this combination could move more quickly into human clinical trials.

A woman comforting her husband, both are elderly with white hair.

Gloved hands holding a glass jar filled with fresh cannabis buds.

Celecoxib has been used for decades to relieve pain, swelling, and stiffness in arthritis patients.

In the study, researchers used very low doses of THC and celecoxib, far below the levels linked to heart risks in past Alzheimer’s trials. Mice received 3 mg/kg of THC and 1 mg/kg of celecoxib per day, roughly equivalent to 18 mg THC and 6 mg celecoxib daily for a 165-pound person.

The combination was tested in two Alzheimer’s mouse models: one representing beta-amyloid plaques and the other tau tangles, both key hallmarks of the disease. Treatment began before memory symptoms appeared, allowing researchers to evaluate whether the drugs could prevent or delay Alzheimer’s, and continued once daily for 30 days.

The results were promising. Low-dose THC alone improved some cognitive performance and reduced certain disease markers, but it also increased signs of inflammation.

The combination, however, produced much stronger effects:

Improved learning and memory
Reduced beta-amyloid plaques and tau tangles
Lowered markers of brain inflammation

Further analysis revealed that genes linked to brain function, inflammation, and Alzheimer’s risk had shifted back toward healthier levels after treatment.

“What really mattered was behavior,” Chen said. “If cognition isn’t improved, the treatment doesn’t matter. And that’s where the combination clearly outperformed THC alone.”

What Comes Next

Looking ahead, the researchers plan to study whether this drug combination can slow disease progression or even reverse brain damage after symptoms appear.

The combination of THC and celecoxib reduced classic hallmarks of Alzheimer’s in the brain, the researchers found.

“This work has taken many years. But now we’re at a point where basic neuroscience discoveries are pointing toward something that could realistically move into the clinic,” Chen said.

Experts note that even delaying Alzheimer’s by just a few years could have a profound impact on patients, families, and the healthcare system.

Alzheimer’s isn’t just about memory loss. Over time, the disease gradually erodes personality, thinking, and reasoning, eventually making even simple daily tasks difficult. On average, people live four to eight years after diagnosis, and Alzheimer’s was the sixth leading cause of death among Americans aged 65 and older in 2022, according to the Alzheimer’s Association.

The risk is significant: more than 1 in 9 Americans over 65 has Alzheimer’s, and a 2025 study found that about 42% of Americans over 55 will develop dementia later in life, with Alzheimer’s being the most common form.

Across the U.S., surveys show that 92% of Americans would take a medication that could slow the disease, and nearly 3 in 5 would accept moderate or high risk to do so.