Can CBD Affect Breast Cancer Cells? What the Research Really Shows

CBD For People June 2, 2025

CBD oil has powerful potential in the fight against breast cancer.

Recent studies into the efficacy of CBD have demonstrated some promising results for those diagnosed with breast cancer. CBD may inhibit mass growth, thus decreasing the size of breast cancer tumors.

This non-psychoactive component of cannabis can also help alleviate the harsh side effects, such as nausea, pain, and vomiting, caused by many cancer treatments.

CBD (cannabidiol), a non-psychoactive compound from the cannabis plant, has drawn attention as a possible complementary therapy in breast cancer treatment. While it’s not a cure or replacement for standard oncology care, early research suggests CBD may have potential benefits for managing symptoms and possibly affecting tumor growth pathways. Here’s what current science tells us—and where the hype stops.

Can CBD Affect Breast Cancer Cells?

Lab Results: Promising but Preliminary

In cell and animal studies, CBD has demonstrated the ability to:

Slow tumor growth: CBD inhibited the proliferation of aggressive breast cancer cells and reduced metastasis in mice.
Trigger apoptosis: It promoted cancer cell death by increasing oxidative stress and altering survival signaling.
Enhance drug response: Some evidence suggests that CBD may boost the effects of chemotherapy drugs like doxorubicin, especially in treatment-resistant forms like triple-negative breast cancer.

However, these are preclinical findings. Human trials confirming these results are still limited or ongoing.

CBD for Symptom Relief During Treatment

CBD may offer relief from several common side effects of breast cancer treatment:

Anxiety: A 2024 study showed CBD significantly reduced scan-related anxiety in women with advanced breast cancer.
Chronic pain: CBD interacts with cannabinoid receptors that influence pain perception, offering potential non-opioid relief.
Nausea and appetite loss: While THC has stronger anti-nausea effects, CBD may still help some patients manage appetite and digestive issues.

Is CBD Safe for Breast Cancer Patients?

Generally, CBD is well tolerated, but there are important caveats:

Drug interactions: CBD can interfere with medications like tamoxifen by affecting liver enzymes (CYP450). This can reduce drug efficacy or increase side effects.
Quality control: Many over-the-counter CBD products are mislabeled or contaminated. Use only third-party tested products from reputable sources.
Dosing: There’s no standard dose. Effects vary based on weight, metabolism, and treatment stage. Always consult your oncologist.