Viagra is widely recognized as the world’s most famous medication for erectile dysfunction.
Since arriving on the market in 1998, the little blue pill has become one of the most familiar pharmaceutical brands ever created, with prescriptions written each year for millions of men — and, in some cases, women.
Now, researchers at the Weizmann Institute of Science in Israel say sildenafil, Viagra’s active ingredient, may offer an unexpected potential benefit: helping to slow or prevent the spread of cancer.
In laboratory experiments using human cells, the scientists found that sildenafil appeared to disrupt cancer cells’ ability to tap into a crucial nutrient they rely on to survive and spread through the body.
The team also examined five million patient records spanning two decades and reported that cancer patients who had used the drug had a 26 percent lower risk of dying within the following five years than cancer patients who had not taken it.
Experts cautioned that the findings remain preliminary and do not prove Viagra can be used as a cancer treatment. Still, they say the discovery could point researchers toward a promising new therapeutic strategy.
Dr Ayelet Erez, the physician-scientist who led the study, said: ‘We have uncovered a new biological pathway that can be harnessed to interfere with cancer’s ability to spread.’
‘Beyond their therapeutic promise, our findings highlight that cancer biology is shaped not only by mutations in tumor cells but also by the patient’s metabolic state and by medications they are already taking for other conditions.’
Since 1998, Viagra has become one of history’s most iconic drugs, prescribed to over 23 million men in its first seven years
It was not clear why the drug may have this effect, but scientists said it interfered with cancer cells ability to absorb cholesterol, a vital ingredient for building cell walls.
In the study, published in Cancer Research, the researchers tested sildenafil on multiple types of cancer cells in the lab, including breast, lung, and colon cancer.
In human cancer cells grown in the lab, sildenafil slowed their ability to move and multiply. The effect was strongest in breast cancer cells, but lung and colon cancer cells also showed significant responses.
They also gave the drug to mice with cancer to see if it slowed the spread of tumors.
In mice, sildenafil dramatically reduced the number of tumors that spread to the lungs – in some cases cutting metastasis by more than half – while having little effect on the original tumor itself.
They also looked at real-world health data from Clalit Health Services in Israel, which covers nearly 5 million people over 20 years.
They compared cancer patients who took sildenafil to those who didn’t, adjusting for factors like age, socioeconomic status, and other medications.
When the researchers analyzed the health records, they found that cancer patients who took sildenafil at least three times in the six months before their diagnosis had a 26 percent lower risk of death within five years compared to non-users.
Sildenafil users had a 26 percent lower risk of death within five years of a cancer diagnosis compared to non-users, with the combination of sildenafil and statins cutting risk by 32 percent. The red line is for people who did not use the drug, while the blue indicates the survival rate in years among those who took the medication
Those who took sildenafil alongside statins fared even better. Their risk of death dropped by 32 percent.
The benefit appeared dose-dependent. Patients with fewer than three sildenafil dispensations showed no significant survival advantage, but those with three or more did.
Among diabetic patients, who are more likely to have sildenafil use documented, the combination of sildenafil and statins was linked to a 41 percent reduced risk of death.
The researchers discovered that sildenafil disrupts cancer cells’ ability to access cholesterol, a nutrient they desperately need to spread.
Cancer cells require cholesterol to build new membranes. But sildenafil blocks cholesterol from being released into the cell, stopping them building new membranes.
In a separate experiment, the researchers also added statins to human cancer cells in the lab that had been exposed to sildenafil.
They found these also helpd to prevent cancer cells from building new cell walls, also potentially helping to slow the spread of the disease.
Studies have also linked sildenafil to multiple other benefits.
In heart disease research, research suggests sildenafil may aid recovery after heart attacks, improve blood flow to the brain in patients at risk of vascular dementia and even stimulate the growth of new collateral arteries to bypass blockages, a process called arteriogenesis.
The brain has also become a major focus. A growing body of research is exploring sildenafil’s potential in Alzheimer’s disease, where it may protect neurons and improve blood flow, though larger human trials are still needed.
Erez’s takeaway goes beyond one drug.
‘Our study underscores the importance of treating the whole patient – not just the cancer.’
