A recent study suggests that sildenafil, the active ingredient in Viagra, may have an unexpected role in restricting cancer metastasis, according to findings published in the American Association for Cancer Research. The research, led by scientists at the Weizmann Institute of Science in Israel and involving the U.S. National Cancer Institute, analyzed human and mouse cancer cells, genetic experiments, and 20 years of health data from 5 million members of Clalit Health Services, Israel’s largest healthcare provider.
The study found that sildenafil, a PDE5 inhibitor, may limit cancer cells’ ability to spread by blocking an enzyme that helps tumors break away from primary sites and migrate. The research team examined how genes, proteins, fats, cholesterol, and cellular energy interact, with a focus on how sildenafil disrupts cholesterol utilization—a key mechanism in metastasis.
Viagra, manufactured by Viatris, was originally developed to treat high blood pressure and chest pain before its use in erectile dysfunction became widely known. The medication increases blood flow by dilating blood vessels, a property now being investigated for potential cancer-related applications.
Researchers emphasized that the findings are preliminary and require further clinical validation. The study’s authors noted that while the results are promising, additional research is needed to determine optimal dosing, safety, and efficacy in human cancer patients. The work was published in a peer-reviewed journal, underscoring its scientific rigor.
The investigation combined genetic experiments, cellular analysis, and large-scale health data to explore the drug’s potential repurposing. The team also assessed how sildenafil’s mechanism—inhibiting PDE5 and increasing cGMP signaling—could interfere with cancer cell migration. While the study does not advocate for Viagra’s use in cancer treatment at this stage, it opens new avenues for drug repurposing research.
Experts not involved in the study have called the findings encouraging but cautious, noting that decades of clinical experience with sildenafil provide a strong safety profile. However, they stress that translating lab and observational data into approved therapies requires rigorous clinical trials. The research adds to a growing body of work exploring drug repurposing—identifying existing medications with potential new applications beyond their original approvals.