Surprising Drug Combination May Slow Alzheimer’s Disease Progression
Researchers at The University of Texas (UT) at San Antonio made a surprising discovery that could prevent the development of Alzheimer’s disease.
In a study conducted on mice, scientists at UT’s Long School of Medicine found that tetrahydrocannabinol (THC) combined with celecoxib improved memory and reduced brain damage associated with Alzheimer’s disease.
THC is the main psychoactive compound in marijuana. The drug is available in synthetic form for nausea caused by chemotherapy and appetite loss in cancer and HIV patients.
Celecoxib is a COX-2 inhibitor commonly prescribed to treat arthritis and pain. COX-2 inhibitors are a class of anti-inflammatory medication that targets the COX-2 enzyme, which is responsible for pain, inflammation, and fever.
Both THC and celecoxib are already approved by the U.S. Food and Drug Administration (FDA) for use in humans. Since the drugs are already FDA-approved, researchers say the combination therapy can move rapidly into clinical trials to evaluate its effectiveness in preventing or delaying Alzheimer’s disease in humans.
“If you develop a new compound, it can take 10 to 20 years to reach patients,” Chu Chen, lead study author and a professor in the Department of Cellular and Integrative Physiology, said in a news release. “In this case, both drugs are already approved. That gives us a real advantage.”
While THC fights inflammation and protects nerve cells from damage, deterioration, or impairment, it has been linked to having negative effects on the brain, particularly in learning and memory, the UT Health press release explained. However, the investigators stated that they successfully decreased THC-related inflammation, all while keeping its cognitive effects intact.
Scientists worldwide have been conducting research to find ways to effectively reduce the risk of Alzheimer’s or minimize its symptoms, which affects an estimated seven million people in the United States. Unless researchers find a way to prevent the progressive disease, the number of Americans expected to develop Alzheimer’s will reach 12.7 million by 2050.
Alzheimer’s, the most common form of dementia, slowly destroys memory, thinking skills, and eventually disrupts daily living activities.
About the UT Study
As part of the study, the UT researchers gave 3 mg/kg of THC and 1 mg/kg of celecoxib to mice for 30 days. The investigators compared this to giving a 165-pound person 18 mg of THC and six mg of celecoxib a day.
The researchers tested low-dose THC alone and also paired THC with celecoxib in mice with beta-amyloid plaques and tau tangles, which are abnormal accumulations of proteins in the brain. These plaques and tangles are primary characteristics of Alzheimer’s disease that researchers say cause neuron damage and cognitive decline.
“Although low-dose THC alone improved cognitive performance and reduced some pathological markers, it also increased inflammatory signaling,” the press release said. “In contrast, the combination of THC and celecoxib produced better outcomes, including improved learning and memory performance, reduced beta-amyloid and tau pathology, and decreased markers of neuroinflammation” (inflammation in the brain or spinal cord).
The findings indicate that combining a low dose of THC with celecoxib might be an effective early intervention strategy for preventing Alzheimer’s disease or treating individuals with mild cognitive impairment.
“What really mattered was behavior,” Chen said in the press release. “If cognition is not improved, then the treatment doesn’t matter. And that’s where the combination clearly worked better than THC alone.”
The study was published in the journal Aging and Disease in December 2025.
Cannabis Compound May Help Reduce Depression and Anxiety
The UT’s study is not the first time researchers have paired celecoxib with a compound found in cannabis plants. A 2024 study published in the journal Cannabis & Cannabinoid Research found that combining celecoxib and cannabidiol (CBD) produced significant antidepressant effects and reduced anxiety in mice.
The researchers gave 10-20 mg/kg of celecoxib and 30 mg/kg of CBD to the mice. The scientists discovered that the drug compound reversed anxiety-like behavior and anhedonia, a primary symptom of depression and other mental health disorders, in the mice. The combination was effective even at lower doses that did not work on their own. Additionally, the study noted that celecoxib and CBD inhibited neuroinflammation (inflammation in the brain or spinal cord) by suppressing microglia activation, a key factor in developing depression and anxiety.
UT Alzheimer’s Research Continues
In future studies, Chen plans to investigate whether THC and celecoxib can either prevent Alzheimer’s from worsening or reverse any damage after symptoms develop.
The ultimate goal is to help patients, their families, and the healthcare systems by delaying or preventing the onset of Alzheimer’s disease by several years.
“This work has taken many years,” Chen said in the press release. “But now we’re at a point where basic neuroscience discoveries are pointing toward something that could realistically move into the clinic.”
Source Links:
https://news.uthscsa.edu/ut-health-san-antonio-research-shows-alzheimers-prevention-potential-in-pairing-cannabis-ingredient-anti-inflammatory-drug/
https://www.newsbreak.com/share/4470755785562-surprising-drug-combo-may-slow-progression-of-alzheimer-s-disease?_f=app_share&pd=0KA7xWlM&lang=en_US&send_time=1769970344&trans_data=%7B%22platform%22%3A0%2C%22cv%22%3A%2225.47.0.44%22%2C%22languages%22%3A%22en%22%7D&s=i3
https://www.aginganddisease.org/EN/10.14336/AD.2025.1206
https://pubmed.ncbi.nlm.nih.gov/36520610/
