Is it safe to take Finastride the rest of your life? Or do you need to ease off of it?

For most men, there is no harm in taking Finasteride for the rest of your life. Everyone is different, however. I recommend you talk it over with your doctor so that you get a better idea on if it works for you or not. 

There are several known problems that exist when using Propecia/Finasteride as a hairloss medication, lets take a look at each one:Finasteride only works for a short
period of time.

 It works for just a few hours a day (its half-life is 6 hours).Finasteride does a poor job of
actually blocking DHT production. Propecia
only blocks 1 out of 3 types of DHT receptors. That means hair loss is
STILL taking place while you are using the medication.  This combined
with the short half life means that Propecia is about 60% effective at
stopping DHT from thinning your hair. Finasteride is not customized to the
individual. Like millions of Big Pharma medications out there, the exact same dose
of Propecia is given to people who have different heights, weights and
biochemistry.  This means that men who want to stop hair loss for good
can take the recommended
dose of Propecia every day, and experience nasty side effects for no
good
reason! While for other's their dose may be insufficient to even reduce
DHT by the 60% it is rated at.It is also worth noting that any
medicine that actually can make changes inside your body, are required
under the FDA to be available by prescription only. This therefore means
that it is not possible for anything that does not require a
prescription to cure or prevent hair loss or regrow thinning hair. Thus,
a personalized medicine will be the best choice because instead of a
"one size fits all" approach, you will be taking something which is
truly catered to your body's needs.

The number one first step I
recommend is a comprehensive consultation with a hair regrowth
specialist who will perform lab tests to determine  the underlying cause
of your thinning. Without labs, no-one can really know what your true
cause is and any treatment will be temporary at best. From here, you can
receive the best treatment for your case.
The treatment is out there. Good luck on your search.