Does Finasteride work forever? It stopped my male pattern baldness. How much longer will it work?

You'll need to continue using Finasteride to maintain results. I suggest seeing a hair loss expert now to go over your condition and provide you information about your best treatment options. There are great non-invasive options like prp/progesterone which can help with hair regrowth and/or hair transplantation. See an expert. Best, Dr. Emer

It’s a good question and likely finasteride will work a long time. One can’t predict for a given person because we don’t know how many genes for balding will be expressed over the next 40 years. Right now you have several genes for balding that are trying to push balding along. However, the reduction in DHT by finasteride is sufficient to hold them all back. Over the next 40 years, you will have more and more genes expressed. Whether this same reduction in DHT will block all balding is hard to say. Most men find there is some loss after 7-8 years but they are always way way better off than having not used it at all. 

The answer is a clear no. Finasteride works well when you are young, but less well as you get older. Sooner or later, your genetic hair loss will prevail over the drug finasteride.