Well dutasteride and finastride are normally used to reduce the size of the prostate with people with enlarged prostates. I can only really comment on Finastride but some people experience issues such as lowered libido, difficulties with erections, problems ejaculating, gynecomastia, depression, impotence etc... But I think these are a minority of men that experience this at the small 1mg dosage. When i say minority, I mean a tiny fraction of the people that use this medication.
Read this:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3481923/I take finastride daily - not for very long just since November/October last year. I havent seen any issues with it yet. My bald spot hasnt gotten worse i think, and I am not sure how much effect it is having. i think it has stopped me losing hair! I HOPE.
I had gynecomastia before going on to fin, it has gotten a bit bigger (my boobs), not much though Im prob just an A cup or something. I don't think my colleagues notice it, if they have they havent said anything. I am not sure if there is any correlation between my gynecomastia getting bigger and taking finastride since I had huge levels of prolactin in my blood prior to starting finastride.
Im sure if you take Dutasteride under the supervision of an endo you will have nothing to worry about.