Most men think of sildenafil and tadalafil as one-trick medications: take one, treat ED, done. But the same biology that makes these drugs work for erections — they improve blood flow by relaxing smooth muscle in blood-vessel walls — turns out to be useful in several other parts of the body. A couple of these uses are already FDA-approved. Others are active areas of research that look promising but aren’t settled science. This article walks through both, and is careful to flag which is which.
Quick, important caveat up front: none of this means you should take an ED medication for anything other than what your provider prescribed. These drugs have real contraindications. The point here is to understand the broader picture, not to self-treat.
First, how these medications actually work
Sildenafil (the active ingredient in Viagra) and tadalafil (Cialis) belong to a class called PDE5 inhibitors. In plain terms: they block an enzyme (phosphodiesterase type 5) that normally breaks down a signaling molecule called cGMP. With that enzyme blocked, cGMP sticks around longer, smooth muscle in blood-vessel walls relaxes, and blood flow improves.1
That mechanism isn’t specific to one organ. PDE5 is found in blood vessels throughout the body — which is exactly why a medication developed with circulation in mind ends up having effects beyond sexual function.
Benefit 1: Enlarged prostate and urinary symptoms (FDA-approved)
As men age, the prostate often enlarges (benign prostatic hyperplasia, or BPH), causing bothersome urinary symptoms — weak stream, urgency, getting up at night. Tadalafil is FDA-approved to treat the signs and symptoms of BPH, including in men who have both BPH and ED.2 So for a meaningful subset of men, a single daily medication can address two issues at once. This is an established, approved use — not a theory.
Benefit 2: A specific form of high blood pressure in the lungs (FDA-approved)
Sildenafil is also FDA-approved — under a different brand name and dose — for pulmonary arterial hypertension, a serious condition involving high blood pressure in the arteries of the lungs.1 It works there for the same reason it works for ED: by relaxing blood vessels and easing blood flow. You wouldn’t use an ED prescription for this on your own; it’s a different formulation under specialist care. But it’s a clear illustration that the underlying drug does real cardiovascular work.
Benefit 3: The cardiovascular and longevity research (promising, but not proof)
This is the part that has generated headlines, and it’s also the part that calls for the most caution. Here’s the honest version.
Start with a well-established fact: because erections depend on healthy circulation, ED is often an early warning sign of cardiovascular disease. The small arteries that supply the penis tend to show the effects of vascular trouble years before the larger arteries of the heart do.34 That link between erectile and heart health is widely accepted by mainstream institutions like Harvard and Mayo Clinic.
From there, researchers asked a natural follow-up question: do men who take PDE5 inhibitors have better cardiovascular outcomes? Several large observational studies suggest an association:
- A 2024 analysis published in Clinical Cardiology reported that, among men with ED, tadalafil use was associated with lower rates of major adverse cardiovascular events and lower all-cause mortality over the study period.5
- A separate 2024 study in The American Journal of Medicine, examining records from more than half a million men, found that PDE5-inhibitor use was associated with lower risk of death, heart attack, stroke, and dementia compared with non-users.6
Read these results carefully. They are observational — they show an association, not cause and effect. Men who are prescribed and take these medications may be healthier, more engaged with their care, or different in ways the studies can’t fully account for. None of this proves that the medication itself prevents heart disease or extends life, and it is not a reason to take an ED drug for cardiovascular protection. Larger randomized trials would be needed to establish causation. The right takeaway is cautious optimism, not a new prescription.
Hear it from our Medical Director
In the short clip above, Dr. Michael Koehler — Affinity Whole Health’s Medical Director — explains how prescription ED medications work and the broader health context men should understand before starting one.
The safety side: this is why it’s prescription-only
The same vessel-relaxing effect that makes these medications useful is also why they aren’t for everyone. The most important rule:
- Never combine PDE5 inhibitors with nitrates (such as nitroglycerin for chest pain). The combination can cause a dangerous drop in blood pressure.1
- Men taking certain blood-pressure medications, or with specific heart conditions, need provider guidance on whether — and at what dose — these drugs are appropriate.
- Side effects are usually mild (headache, flushing, nasal congestion), but they’re real, and dosing matters.
This is exactly why a licensed provider reviews your health history before any prescription is issued — to make sure the medication is safe for you, not just effective in general.
The bottom line
Sildenafil and tadalafil are better understood as circulatory medications that happen to be best known for treating ED. Two of their uses beyond sexual function are FDA-approved (BPH and pulmonary arterial hypertension), and the cardiovascular-longevity research is genuinely interesting — while still being observational and unproven as cause-and-effect. The practical move isn’t to chase secondary benefits; it’s to treat ED properly, under real medical supervision, and let the rest be a conversation with your provider.
At Affinity Direct, the online arm of Affinity Whole Health, that supervision is built in: a licensed provider reviews your intake (typically within 24 hours), and your card is charged at checkout with a full refund if treatment isn’t approved. ED treatment starts from $0.78/day, with free, discreet 2-day shipping.
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This article is for general education and isn’t a substitute for personalized medical advice. Do not start, stop, or combine medications without speaking to a licensed provider. Never take a PDE5 inhibitor with nitrates.