In regards to thinning hair, I am 49 years old and had the same problem.
However I believe my problem was due to damaged hair from coloring and blow drying. It had become very dry and brittle and of course I noticed the thinning near the front. A remedy I used which has been very helpful was to massage warm olive oil into my hair and leave it on as long as possible. Sometimes I would do this on my day off and leave it on till the next morning, when I washed it out my hair felt wonderful. Shortly after that I noticed my hair was getting thicker too! After trying it I started doing some research on Olive oil and its benefits for hair and sure enough I came across other testimonials were they too noticed a thicker mane of hair.
For me, olive oil has become a regular on my bathroom shelf. (Extra virgin oil is the best!)