CBD to Alleviate ‘Chemo Brain’ in Cancer Survivors

A new study by UC Irvine researchers suggests that CBD can help treat “brain fog” for people with cancer-therapy-related cognitive impairments (CRCI), addressing an unmet medical need.

Irvine, Calif., June 18, 2026 — The U.S. currently has 18.6 million living cancer survivors, approximately 35–70% of whom suffer from cancer-therapy-related cognitive impairments (CRCI) — also known as “chemo brain.” CRCI, which can result in memory loss, difficulty concentrating, anxiety and depression, is a long-term issue severely impacting people’s quality of life.

“Our study identifies a potential endocannabinoid-based therapy to address a critical unmet medical need that cancer survivors experience,” says Shreya Madan, a student researcher at UC Irvine and recent graduate of the Master of Science in Biomedical and Translational Science (MS-BATS) program. “CBD may help to provide a personalized and effective therapeutic option for cancer survivors facing cognitive deficits.”

The findings appear in a research article published in Cancer Letters.

Cancer & Cannabis Use

“Cannabis use among cancer patients and survivors is increasing globally, with reported prevalence ranging from 13% to 42%, depending on cancer type,” explains Munjal M. Acharya, PhD, an associate professor in the Department of Anatomy & Neurobiology who led the study.

Cannabis contains two main compounds: THC, which has psychoactive effects, and CBD, which is non-psychoactive and causes minimal behavioral changes in preclinical models.

“Despite growing use,” says Acharya, “significant gaps remain in understanding the role of CBD in managing cancer-related cognitive impairment and other survivorship symptoms.”

To advance research on CBD in the field of cancer neuroscience, the study was a collaboration with researchers from the UC Irvine Center for the Study of Cannabis, including Daniele Piomelli, PhD, the center’s director; Kwang Mook Jung, PhD, an associate professor of anatomy and neurobiology; Alexandre Chan, PhD, a professor of clinical pharmacy and CRCI expert; and Kalpna Gupta, PhD, a professor of medicine.

Understanding CBD’s Potential

In an experimental study, the researchers investigated the neuroprotective effect of oral administration of 99% pure cannabidiol — CBD without any THC contamination — in sesame oil in a CRCI mouse model. The researchers used one of the purest forms of CBD, which closely resembles Epidiolex®, an FDA-approved medicine for certain pediatric epilepsies.

“We found that CBD administration significantly improved learning and memory, executive functioning, and memory consolidation processes, which are often impaired in patients following clinically relevant adjuvant chemotherapy — Adriamycin and cyclophosphamide,” says Madan.

Sanad M. El-Khatib, a pre-med student researcher involved in the work, adds that CBD had other beneficial effects as well.

“Importantly, CBD also restored neuronal plasticity-related immediate early gene (cFos) expression, restored neurogenesis and synaptic integrity, reduced neuroinflammation, and stabilized the body’s own endocannabinoid metabolism, which was disrupted by chemotherapy,” says El-Khatib. “CBD thus serves as a promising therapeutic for CRCI patients.”

By reversing synaptic density loss, neuroinflammation, and cognitive dysfunction, CBD shows potential in treating the underlying mechanisms that cause CRCI.

“Our results exemplify a translationally feasible therapeutic,” says Acharya.

About the UC Irvine School of Medicine: Each year, the UC Irvine School of Medicine educates more than 500 medical students and over 180 PhD and MS students. Nearly 900 residents and fellows are trained at the UCI Medical Center and affiliated institutions. The School of Medicine offers multiple MD, PhD and MS degrees, and students are encouraged to pursue an expansive range of interests and options. The UC Irvine School of Medicine is accredited by the Liaison Committee on Medical Education and ranks among the top 50 nationwide for research. For more information, visit medschool.uci.edu.