Can Viagra Fight Cancer? The Surprising New Science of Sildenafil, Cialis, and Longevity
Looking for another reason to take Viagra? How about this one: it may help stop cancer from spreading.
A fascinating new 2026 study published in Cancer Research found that sildenafil, the generic drug better known as Viagra, interfered with cancer cells’ ability to spread.
Here’s the deal. The tougher it is for cancer cells to move around, the better. In both mouse and human cancer models, PDE5 inhibitors (the medication class that includes Viagra and Cialis) slashed the ability of cancer cells to spread. How? They impaired cancer cells' ability to access cholesterol. Cancer cells need cholesterol to build their membranes, grow, and travel through the body. Sildenafil essentially trapped some of that cholesterol inside the cells’ recycling compartments, leaving less available to support migration and metastasis.
When researchers combined sildenafil with statins, which reduce the production of new cholesterol, the effects appeared complementary. An analysis of electronic health records also found better survival among cancer patients taking sildenafil, with an additional association among those also using statins. In other words,
PDE5 inhibitors and statins like Crestor might be a 1-2 punch against cancer spread.
Before you raid your medicine cabinet, this is not proof that Viagra treats cancer. Much of the work was laboratory and animal research, and the human findings were observational. We need to test this on real humans, not laboratory models.
Why Would Viagra or Cialis Have Benefits Beyond Sex?
Beyond being a concierge longevity medicine physician, I’m also a pediatric anesthesiologist. I first encountered sildenafil in a surprising setting: the neonatal intensive care unit (the NICU). We use sildenafil in seriously ill tiny babies with poor blood flow to their lungs (pulmonary hypertension). Sildenafil relaxes the lung’s blood vessels and makes it easier for the heart to pump blood to their immature lungs.
So when someone tells me Viagra is just a medication for erections, I know better. Erections are what caught everyone’s attention, but the mechanism of action is via the blood vessels.
PDE5 inhibitors amplify nitric oxide signaling, relaxing smooth muscle and improving blood flow. The penis happens to be one place where this is particularly noticeable, but PDE5 and the nitric oxide pathway are found throughout the body.
That explains why these medications have other legitimate medical uses. Sildenafil and tadalafil are prescribed for pulmonary arterial hypertension. Daily tadalafil is also FDA-approved for symptoms of an enlarged prostate, including weak urinary flow, urgency, frequency, and waking up at night to pee.
Heart Attacks, Strokes, and Longevity
PDE5 inhibitors seem to have some cool cardiovascular benefits.
A 2024 meta-analysis of 13 studies found that long-term PDE5 inhibitor use was associated with lower cardiovascular events and about 30% lower overall mortality. These weren't mostly randomized longevity trials, so we have to take the results with a grain of salt. In other words, we don’t know for sure whether the medications make men live longer or whether the types of older men who will live longer are more likely to use Viagra. In other words, men who seek treatment for erectile dysfunction may exercise more, have more sex, take better care of themselves, have better relationships, or differ from untreated men.
An enormous 2025 study really turned me and the rest of the longevity community on to PDE5 inhibitors. Researchers studied more than 500,000 men with erectile dysfunction. Compared with similar men who weren't taking the medications, tadalafil users had 34% lower mortality, 27% fewer heart attacks, 34% fewer strokes, and a 32% lower risk of dementia over three years. Sildenafil showed benefits in the same direction, although generally smaller. Again, this was observational research, not proof that Cialis prevents heart attacks.
What About Viagra, Cialis, and the Brain?
Yup, they may even help prevent Alzheimer’s.
A 2025 meta-analysis involving more than 885,000 people found that sildenafil users had roughly half the observed risk of developing Alzheimer's disease compared with non-users. Other research has found associations between PDE5 inhibitors and lower dementia risk, and laboratory studies suggest sildenafil may affect blood flow and Alzheimer's-related processes inside brain cells.
But don't order a lifetime supply of Viagra just yet. An NIH-supported analysis reached the opposite conclusion, finding no reduction in Alzheimer's or related dementia among people taking sildenafil or tadalafil. A clinical study of tadalafil and cerebral blood flow also failed to demonstrate the dramatic brain benefit that enthusiasts might hope for.
My interpretation? The dementia story is fascinating and biologically plausible, but far from proven.
Longevity researcher David Sinclair recently suggested low-dose daily Viagra or Cialis may be useful for maintaining vascular function in the brain and muscles, while acknowledging that dementia prevention remains unsettled.
Should Women Take Viagra?
I know, I know. Almost all the headlines make Viagra sound like a men's longevity medication.
But the biology isn't uniquely male. Sildenafil and tadalafil affect blood vessels throughout the body, and PDE5 inhibitors are already prescribed to women with pulmonary arterial hypertension. In fact, women have made up the majority of participants in some major pulmonary hypertension trials involving tadalafil.
However, most of the exciting cardiovascular and dementia observational data we've been discussing come from men, largely because researchers studied populations receiving the drugs for erectile dysfunction. We simply don't know whether healthy women would experience the same long-term benefits.
So, could these drugs eventually prove useful for vascular or brain health in women? Sure. Most likely, I’d say. Is there enough evidence today for healthy women to routinely start taking Cialis for longevity? Not yet.
Viagra or Cialis: Which One Is Best?
If we're talking about established treatment for erectile dysfunction, both work well. Sildenafil is shorter-acting, with a half-life of roughly four hours. The usual starting dose for ED is 50 mg taken as needed, although prescriptions range from 25 to 100 mg.
Tadalafil hangs around much longer. Its half-life is about 17.5 hours, and its erectile effects can last up to 36 hours. For ED, it can be taken as needed, usually starting at 10 mg, or used daily at 2.5 to 5 mg. For urinary symptoms from benign prostate enlargement, the FDA-approved dose is 5 mg daily.
If future research proves that PDE5 inhibitors have meaningful preventive effects on the heart or brain, tadalafil may ultimately be the better drug because it provides continuous exposure and has shown particularly strong associations in recent observational studies. But that's just a guess.
There is currently no FDA-approved “longevity dose” of Viagra or Cialis, no proven dose for preventing Alzheimer's disease, and certainly no established regimen for preventing cancer. I would be very wary of anyone pretending otherwise.
Who Shouldn't Take Viagra or Cialis?
These medications have been around for decades and are generally well tolerated, but they aren't candy.
The biggest danger is combining them with nitrate medications such as nitroglycerin or isosorbide, or recreational nitrites sometimes called “poppers.” The combination can cause a dangerous drop in blood pressure. They also should not be combined with the pulmonary hypertension drug riociguat. People taking alpha-blockers, multiple blood-pressure medications, or certain medications that alter PDE5 drug metabolism require additional caution.
People with very low blood pressure, significant unstable cardiovascular disease, severe kidney or liver problems, or certain eye disorders need individual medical assessment before using them. Common side effects include headache, flushing, nasal congestion, indigestion, and back or muscle aches. Rare but serious problems include prolonged erections, sudden hearing loss, glaucoma (with Cialis), and sudden vision loss.
In other words, please don't buy mystery “longevity Cialis” off the internet because a podcaster mentioned it. Speak to your doctor before starting a PDE5 inhibitor or any other medication.
So, Should We All Take Low-Dose Cialis?
Not yet. But maybe one day.
Sildenafil started life as a cardiovascular drug, became one of the most famous sexual medications in history, and is now being investigated again for cardiovascular disease, dementia, cancer, and other diseases of aging. Pretty cool.
The new research is exciting. The cardiovascular benefits seem solid, the brain findings deserve more study, and the new cancer/cholesterol research is downright fascinating. At the same time, we don't yet have the type of randomized, long-term evidence that these medications will make you live longer.
I’m not saying don’t take these medications. In fact, I recommend them to many of my concierge longevity patients. Many middle-aged and older adults already have legitimate reasons to consider a PDE5 inhibitor: erectile dysfunction, prostate-related urinary problems, or pulmonary hypertension. If future benefits to vascular health eventually prove real, they would be a pretty sweet bonus.
This is how I approach medications in my concierge longevity work. I'm not interested in stuffing patients with an enormous “anti-aging stack” because the latest influencer got excited on a podcast. I would rather identify common-sense treatments tailored for the individual, have a strong safety record, address an actual problem, and perhaps offer additional benefits along the way.
Sometimes old drugs surprise us. Viagra certainly has before.
It may do it again.
Gregory Charlop, MD, DipABLM, is a Chief Wellness Officer (CWO) and concierge lifestyle and longevity doctor for family offices in Atlanta, Texas, and California. He's a keynote speaker at the Barron's Advisor 100 Summit and a member of the Barron's Hall of Fame. He helps busy middle-aged executives build healthier futures and prepare for retirement with modern lifestyle design and common-sense lifestyle medicine. Featured on FOX Business, ABC, NBC, FOX, and Forbes, Dr. Charlop is a Georgia-based, Stanford-trained physician, keynote conference speaker, and author of four books.
