You take it for this purpose or why?

It is prescribed for benign prostatic hyperplasia (BPH; an enlarged prostate) which include difficulty urinating—not just for ED

Just hijacking to add a public health warning about BPH. Like many men as they get older, I was getting up several times a night to pee. Thought I would just put up with it until it got worse.

I went on a yacht for the weekend, drank quite a few beers and crashed to sleep.

I awoke to find out I couldn't pee at all. I can't describe how painful things were by the time I staggered into the emergency department that evening. Definitely the worst experience of my life. A few weeks later a guy was winched off a boat by helicopter with the same condition - one of his mates had been tasked with catheterising him using the rubber fuel hose from the boat's engine, but was unsuccessful.

If you are having trouble urinating, seek medical attention - don't ignore it.

Ignoring prostate issues for 6 months got me to the edge of sanity - I was 26 then and was told there was no way I have prostate issues.

why on a yacht, though? i have a similar problem. shy bladder plus tense pelvic base. maybe even somewhat increased prostate (i don't know). so peeing is always something i need a little privacy for. but everytime i'm scuba diving plus out with a boat it's like my prostate is locking up completely. extremely weird and uncomfortable feeling. on those small boats there is never a toilet but there are sneaky options that in theory should work but don't. so i'm wondering if the wavy motion might have something to do with this problem.

Is there some correlation to boats or just happenstance?

Just coincidence, situations where one might drink too much and be isolated from medical care.

I take it on doctor’s orders to recover from prostate cancer. Improving the circulation in that area should help rebuilding tissue.

There are many off label uses. Pulmonary Hypertension for one.

BPH smptoms I started having in my '60s turned out to go away when I stopped taking antihistamines for seasonal allergies.

ouch thank you for explaining your usecase

If you want to pretend to be old, Strattera gives you the effects of this as a side effect.

Another weird effect was that my ejaculation and orgasm were seconds apart. Don’t remember which came first (pun). Hated that drug.

now you have my attention.

I do the same because 20 years ago a roadside bomb blew up next to the vehicle I was riding in and caused it to roll over and down an embankment and the repeated impacts compressed my lumbar discs which after about 10 years manifested as degenerative disc disease at L5-S1 and a series of disc bulges and scar tissue build-up up and down my lumbar region that compressed the nerves leading to my genitals and ultimately led to a spinal fusion of that area...

...and a low dose makes it so my penis functions normally.

It's fantastic, really.

Looks like 5mg viagra is 10%-20% of the minimum recommended dose for viagra's original purpose

GP is talking about cialis (tadalafil), a completely different drug. It is dosed differently from viagra (sildenafil).

Thanks! I thought they were the same

5mg of tadalafil would be 50% of the typical “as needed” dose for its original purpose

10mg works really well in my experience.