How Long Does Finasteride Work?

I’ve used Min and Fin for 18 months, and it’s worked well. It’s slowed recession to 85-97% – though it’s hard to be objective – and there’s some light Min regrowth around my hairline. If it kept working like this indefinitely, I’d be rapt. … and that’s what I’m wondering. Many users – and, IIRC, studies – report efficacy of both these medications to at least somewhat dip over time. But I’ve anecdotally seen people on other forums talk about 10-15 years of use.

So how many Fin users ( and/or Big 3 users ) have reported good results from the drugs that have simply maintained anywhere near the same level of results over 5-10+ years? In other words: who has kept near to what they started with and had decent-to-strong long-term results – and/or even gains? 

I have seen the Finasteride work for as long as it has been on the market. I know that because one of my patients, 62, was on it since it was released, but decided to stop it and got “catch-up hair loss”. He was devastated. He went back on the drug, but did not get all of his hair back.