Viagra Could Help Stop Cancer From Spreading
Viagra reduced cancer metastasis in models by blocking cholesterol use in tumor cells.
The world’s most famous blue pill might soon take on an entirely new role as a weapon against cancer.
Researchers at the Weizmann Institute of Science discovered that Viagra™ (sildenafil) restricts cancer metastasis by trapping essential cholesterol inside tumor cells, cutting off their energy.
When paired with regular cholesterol-lowering statins, this combination created a metabolic trap that boosted long-term patient survival rates in real-world clinical records.
The many uses of Viagra
Since its medical approval, tens of millions of people worldwide have used Viagra. Although it is most famous as a treatment for erectile dysfunction, its journey began as a cardiovascular drug. Now, this medication is moving into an entirely new clinical domain: oncology.
To survive and migrate, cancer cells hijack normal cellular signaling pathways. By understanding these pathways, researchers can intercept cancer cells before they spread throughout the body.
Metastasis remains the primary cause of cancer mortality, causing ~90% of all cancer deaths. To tackle this deadly spread, scientists have spent years looking at existing drugs that might disrupt tumor survival pathways.
The impact of phosphodiesterase type 5 (PDE5) inhibitors, such as Viagra, on cancer progression has remained controversial, with clinical data showing conflicting outcomes. Researchers have hypothesized that this confusion stems from an unrecognized function of the signaling molecule cyclic guanosine monophosphate (cGMP).
cGMP
cGMP is a chemical messenger inside cells that passes along biological signals to trigger bodily functions, such as relaxing blood vessels and regulating how cells process nutrients such as cholesterol.
Earlier work by the team demonstrated how tumor cells manipulate metabolic loops to fulfill nutritional demands and evade the host immune system.
Since these loops often rely on signaling molecules, the team realized that a common drug known to alter these exact chemical signals—Viagra—might hold promise for breaking the cycle. By disrupting cancer’s metabolic signaling, its metastatic capacity may also be impaired.
The new study aimed to map out how PDE5a inhibition restricts cancer cell migration. By focusing on an approved drug, the team can bypass years of early development and target the exact mechanisms by which tumors spread.
Viagra cuts off tumor cholesterol and energy
The team analyzed 2D and 3D cell cultures across breast, lung, colon, and prostate cancers, alongside patient breast cancer biopsies. They also tracked primary tumors and lung metastasis in mouse models using tools such as lipidomics, mass spectrometry, and genetic knockouts. They also analyzed 20 years of health records from 5 million people, tracking 40,567 male cancer patients.
They found that Viagra primarily targets the metastatic cascade rather than local tumor growth. In mice, primary tumors were unaffected, but lung metastases dropped.
When Viagra blocked PDE5a, it triggered a surge in cGMP, which bound directly to the NPC1 transporter at the exact site usually reserved for cholesterol, effectively blocking its export.
Starved of usable cholesterol, the cancer cells’ membrane lipid rafts were disrupted and mitochondrial membranes were destabilized, slashing energy production and preventing migration. This metabolic shutdown specifically targeted tumor cells while leaving healthy, normal cells completely unharmed.
Pairing Viagra with statins, which halt cholesterol production, created a metabolic trap; cancer cells couldn’t access existing cholesterol and were prevented from making more. This combination yielded the lowest migration rates in the lab and the lowest metastatic load in mice.
The real-world human data mirrored these findings, showing improved five-year survival rates for cancer patients taking Viagra, with a dose-response pattern boosted by statins.
Cell and Gene Therapies: The Evolution of Advanced Biologics
This eBook takes a look at the challenges shaping advanced biologics, alongside practical strategies to improve consistency, scalability, and compliance across development and manufacturing.View eBook
The clinical potential and future of Viagra in oncology
The findings show that tumor biology is shaped by the patient's systemic metabolic state and daily medications, as well as internal genetic mutations.
“We have uncovered a new biological pathway that links a well-known signaling molecule to cholesterol regulation within cells, and shown how this pathway can be harnessed to interfere with the ability of cancer cells to form metastases,” said corresponding author Prof. Ayelet Erez, a senior researcher and dean of Weizmann’s Miriam and Aaron Gutwirth Medical School, who is also a practicing physician.
This work provides a framework for repurposing safe, inexpensive existing drugs like Viagra and statins as immediate therapy for aggressive metastatic cancers.
However, the study has limitations: as a retrospective medical record analysis, it relied on dispensing data, potentially missing patients who purchased Viagra privately.
Moving forward, prospective clinical trials to validate the drug combination while tracking cancer stages and chemotherapies could aid future development. More research is also needed to explore whether the vasodilatory effects of Viagra mechanically improve chemotherapy delivery.
“Our study underscores the importance of treating the whole patient—not just the cancer—when tailoring the most effective therapy,” said Erez.
Reference: Ariav Y, Hayek S, Cantore T, et al. PDE5A inhibition restricts cancer metastasis by disrupting NPC1-mediated cholesterol trafficking through a non-canonical cGMP-dependent pathway. Can Res. 2026. doi: 10.1158/0008-5472.CAN-26-1818
This article is a rework of a press release issued by the Weizmann Institute of Science. Material has been edited for length and content.
Add Technology Networks as a preferred Google source to see more of our trusted coverage.
