Tadalafil for Longevity at 71: Why I Ordered It

I was reading through Bryan Johnson’s new site the other day, and there it was in the product list: tadalafil. The generic version of Cialis. Sitting on a longevity storefront next to the supplements.

I ordered it. The tablets arrived this week. I have not taken one yet, and there is a reason for that, which I will get to.

The Part That Surprised Me

This is a prescription drug. I expected the process to be a wall. It was not.

You fill out a health questionnaire on the site, a licensed physician reviews it, and if they approve you, it ships. No office visit, no waiting room, no three-week appointment. Depending on your state you may have to do a short video or phone consult first.

I have mixed feelings about how easy that was. On one hand, this is how it should work — I am 71, I track my own bloodwork twice a year, and I should not have to burn a morning in a waiting room to get a well-understood generic. On the other hand, a form on a website is a thinner filter than a doctor who knows your history. If you are on heart medication, or you have never had your blood pressure properly measured, that thin filter is a real problem and not a convenience.

If you go this route, make sure the prescriber ends up knowing every medication and supplement you are already taking. That is on you as much as on them.

Why Bryan Johnson Takes It

He is not taking it for the reason most men take it. He publishes his whole protocol, and tadalafil 5 mg daily is on it, listed for endothelial function, inflammation, and protection against age-related cardiovascular and metabolic decline.

The mechanism is the interesting part. Tadalafil blocks an enzyme called PDE5. Blocking it lets a signalling molecule called cGMP build up, and cGMP is what tells the smooth muscle in your blood vessels to relax. That is why it works for erections. It is also why people think it might do something for the rest of the plumbing — the same lining, the endothelium, runs through every artery you own, including the ones feeding your brain.

That is the theory. Here is what the evidence actually looks like.

What the Research Actually Shows

The strongest-looking numbers come from a large database study of men with erectile dysfunction. Compared with men not on these drugs, tadalafil users had lower three-year risk of dying from any cause, of heart attack, of stroke, of blood clots, and of dementia — with tadalafil showing a bigger effect than sildenafil (PubMed 39532245).

Those are eye-catching numbers. They are also observational, and that matters enormously.

Think about who gets prescribed this. Men who go to a doctor. Men who ask for something. Men healthy enough to be interested in sex and well enough to be given a vasodilator. Compare that group to men who never got a prescription and you are not just comparing a drug — you are comparing two different kinds of patient. Researchers call it confounding by indication, and it is the reason a lot of promising drug associations evaporate when somebody finally runs a proper trial.

Where It Falls Apart

The dementia claim is the one you see repeated most, and it is the one with the messiest evidence underneath it.

Some meta-analyses find a large reduction in Alzheimer’s risk among PDE5 inhibitor users. But in the one covering more than eight million people, the significant effect was in sildenafil specifically — the tadalafil results were not significant (PMC11470851).

Then it gets worse for the theory. A real-world study in Israel followed daily low-dose tadalafil users, the exact thing I just ordered, and matched them against a comparable drug group. It found no reduction in dementia risk (PubMed 38952132). And a Mendelian randomisation study, which uses genetics to get around the confounding problem entirely, found no causal link between PDE5 inhibition and Alzheimer’s at all (PMC12686590).

That last one is the study I take most seriously, because it is designed to answer the exact question the database studies cannot.

So the honest summary is this: the vascular rationale is sound, the human outcome data is associational and may be measuring the patient rather than the pill, and the brain claim is probably oversold.

Then Why Did I Order It?

To be clear about my own reason: I ordered this for what it might do to my blood vessels, not for anything else.

Because I am running an experiment on myself in public, and because the downside profile of a low-dose generic is well understood after twenty-five years of use.

That is a different standard than “the science says it works.” The science does not say that. What it says is that the mechanism is plausible, the drug is cheap, the side effects are known, and there is a signal in the population data that nobody has yet confirmed or killed with a proper trial.

I am comfortable being one data point inside that uncertainty. You may not be, and that is a completely reasonable place to land.

What I Am Doing Before the First Tablet

Nothing, for three days.

This is a vasodilator taken every day. If it does anything measurable to me, it should show up in my blood pressure. So before I swallow a single one, I am taking my blood pressure every morning for three days — same cuff, same arm, sitting — and logging resting heart rate and HRV off my Ultrahuman Ring alongside it.

If I skip that, I lose the baseline permanently. Six weeks from now I would be telling you my blood pressure is some number, with nothing to compare it to, and that is worth exactly nothing. It is the same mistake I see in most supplement reviews online, including some I wrote before I knew better.

Then daily dosing, with the same readings at two weeks and six weeks. Daily tadalafil takes about five days to reach steady state, so anything I notice in the first two days is noise, not results.

I will also be logging the boring stuff: headache, flushing, blocked nose, back and muscle ache. Those are the common side effects and they usually settle in the first week or two. If mine do not, you will hear about that too.

One Warning I Am Not Going to Bury

Tadalafil must never be combined with nitrate medication — nitroglycerin, isosorbide, the heart drugs. Nitrates donate nitric oxide, tadalafil stops the downstream signal being cleared, and together they can drop your blood pressure hard enough to put you on the floor.

I do not take nitrate drugs. But three things in my daily routine are aimed at the same pathway from the other end: nitric oxide lozenges every day, CardioSmile nitric oxide toothpaste (my review), and a morning pack of VINIA Blood Flow Hydration electrolytes, which the company says raises nitric oxide production (why I take it). None of those are nitrate medications and it is not the same interaction — but they push blood pressure the same direction, so they belong on the list of things a prescriber should hear about, and I am watching my blood pressure for it.

Also worth knowing: sudden vision loss on this drug means stop and get seen the same day. And grapefruit raises the levels in your blood.

Where This Goes Next

I will report the numbers in six weeks, whatever they say. If my blood pressure does not move, I will tell you it did not move. If I feel nothing, I will tell you I felt nothing.

That is the whole point of doing this in the open. Everything else I take is on my protocols, every blood panel is in test and stats, and the training side is under fitness.

For the record, I have no affiliate relationship with Immortals and I paid for this myself. Some of the other product links in this post are affiliate links, which means I may earn a small commission at no extra cost to you.

Have you tried daily tadalafil, or talked to your doctor about it? Tell me in the comments — especially if you are over 65.

Live long and prosper,
Gary

A note from Gary: I am not a doctor, and I am definitely not your doctor. I am a 71-year-old man running a 129-year experiment on himself in public. Tadalafil is a prescription medication and this post is not a recommendation that you take it. Nothing here is medical advice. Talk to your physician before changing anything, and do not start any vasodilator without telling them every supplement and medication you are already on.