I get my Finast (Dr Reddy's) from United. I have no reason to suggest it isn't legit stuff. Been on it two months and in conjunction with the other stuff I'm doing something is working as my hair hasn't been this good for a couple of years. I did a lot of research before deciding on United and...
Been taking Finast (Dr Reddy's) 1/4 a day for around the same time. Exactly the same. No sides, although when I feel unwell I convince myself it must the finasteride!
I once took a photo in the Far East 21 years ago on a hill under a very very bright sun. You couldn't see any hair on the top nor the sides. I looked like Kojak! I wasn't going bald then but like you I have incredibly fine hair. It's the way it is for some of us!
I took Saw Palmetto (P*R*O*C*E*R*I*N variant) for about 8 months and in that time I don't believe it did anything. If you do a bit of Google research you'll find that many believe the sides of Saw Palmetto are the same as finasteride but you don't get the benefit of finasteride. Personally, mixing Daktarin...
If you are UK based, Asda sell a really cheap Alberto Balsam Tea Tree & Mint conditioner. It's £1 and it's very, very good. Makes my hair feel and look much thicker & healthier.