Laboratory research suggests two cannabis compounds, tetrahydrocannabinol (THC) and cannabidiol (CBD), have potent anti-tumor effects against ovarian cancer cells and may inform future therapeutic approaches. Published in Frontiers, the study found that both compounds reduced cancer cell growth, spread, and survival across multiple tested measures.
Researchers exposed two ovarian cancer cell lines—one platinum-sensitive and one platinum-resistant—to THC and CBD in vitro. Both compounds killed cancer cells at doses much lower than those harming healthy cells, demonstrating selective cytotoxicity. The platinum-resistant line showed greater responsiveness at higher doses. When combined at a 1:1 ratio, THC and CBD acted synergistically and produced stronger anticancer effects than when used alone.
Key cellular effects observed included reduced clonogenic potential (the ability of cancer cells to divide and regrow), induction of apoptosis (programmed cell death) in roughly a quarter of cancer cells, decreased metastatic potential, and inhibition of signaling pathways that drive cell growth. The researchers reported THC and CBD appear to suppress expression of important proteins within these pathways, thereby slowing tumor-promoting signaling.
Lead author Siyao Tong, MD, noted the results align with broader literature suggesting cannabinoids could serve as adjuncts to cancer therapy. Independent experts called the findings an encouraging early step, while emphasizing that extensive animal and human studies are required before clinical use.
Beyond direct anticancer activity, CBD and THC have established benefits for symptom management—particularly anti-nausea, anti-inflammatory, and analgesic effects—which could improve quality of life during treatment. The investigators proposed that cannabinoids might be used alongside standard platinum-based chemotherapies to help overcome chemoresistance while providing symptomatic relief.
Ovarian cancer is the second most common gynecologic cancer in the United States and causes more deaths than any other cancer of the female reproductive system; in 2025 there were an estimated 20,000 cases and more than 12,000 deaths. Because the disease often presents with non‑specific symptoms and is diagnosed at later stages, new therapeutic options are urgently needed.
The study strengthens the rationale for further preclinical and clinical research into cannabinoids as complementary agents in ovarian cancer treatment, but clinical recommendations await validation in animal models and human trials.
