Did u take it right away at the first signs of hairloss? I havent lost my hair yet but a few close relatives have, maybe i should tell them to try it.
I will tell you my experience, then note the recent studies & research.
I always had a thick full head of hair. And on both sides of my family (I believe the mother's side is the link for hair retention vs. hair loss/going bald) had full heads of hair. When I got my hair cut, my barbers and beuty salon cutters would use thinning shears. My hair was that thick.
Then all of a sudden, my hair started falling out: I saw in on my pillow, in the sink when I brush sink, at the bottom of the tub after a shower, and on tables when I sat at them. Even the lady that cut my hair for years, noted the rapid loss of my hair. I was shedding like a dog.
What did I do after about 2 months and realizing that I was on the path to being bald at a young age? I went to my Dermatologist and he did 2 biopsies and tested my blood. The result was male-pattern baldness.
My hair kept shedding and after 2 years I did what is common. I grew my hair long, and combed my bangs back and long hair back with gel.
And the hair kept going.
Then, in 1998, my Dermatologist told me about Finesteride. A drug then (and now) sold under they name by Merk called "Propecia." Now you can get generic and cheaper pills. Maybe $10-15 per month or less.
How do I know it worked for me?
I stopped taking it twice. Just to see.
And my hair fell out right away. Too quickly.
As for when to start, the sooner you start the more hair you'll keep. I however, actually grew my hair back, and now have a short full head of hair.
There are many studies on this if you google.
I'm not selling it, but check it out, if you care.
Cheers. Smoothy.