Are cut finasteride pills effective?

I have been taking 1mg finasteride tablets for the past couple years. I recently experimented with breaking the tablets in half (I have the white octagonal tablets), and my side effects went away. However, my hair also began falling out after 2 weeks. Does breaking the tablets in half affect how they are absorbed? I am not sure if these tablets have coating or not (it’s hard to tell, unlike the red tablets, which appear to be coated), but if they do, does the coating help the drug get absorbed in a more effective manner? Is it possible that by breaking up the tablet and exposing its internal non-coated portion, some of it is going to waste and I am not getting the full .5mg? If there is no absorption issue, is there any risk pertaining to the tablet contents not being dispersed evenly throughout the volume of the tablet?

If you reduce your dose from 1mg to 0.25 mgs, that will reduce the effectiveness of finasteride and could cause hair loss, as in your case.  Cutting the pills frequently is the way to go, so that cut pills are kept in an air tight sealed container and only done for a few day supply.  Never cut in advance for a month, for example.