Why not just use 1mg tablets and cut them in half. This will be far easier than trying to cut a 5mg tablet into ten. You will get a very uneven dose in each piece if you try to divide your tablets into ten, and a lot of finasteride dust will be lost in the process. If you really do want to stick with 5mg tablets, however, maybe cut them into sixths? This will be easier than cutting into tenths, and will give you an approximate dose of 0.8mg in each piece. 0.8mg will inhibit pretty much the exact same amount of DHT as 0.5mg, so it is essentially a distinction without a difference. This is in fact true for all doses of 0.5mg and upwards (even 0.2mg inhibits very close to the same amount of DHT as a full 5mg dose). Since DHT inhibition is essentially identical between all doses of 0.5mg and upwards, the only logical reason why a person should opt for a 0.5mg dose instead of a higher dose would be due to affordability.