36yr old male with diffuse thinning all over scalp since aged 15. It has got lot worse laser two years with Inc shedding?

This needs an in-person evaluation. I suggest seeing a hair loss expert now to evaluate and go over your condition and provide you information about your best treatment options. There are great non-invasive options like prp/progesterone and/or hair transplantation. See an expert. Best, Dr. Emer

If you have thinning all over the scalp, you may in fact have diffuse unpatterned alopecia (DUPA). This is a form of androgenetic alopecia. Options for treating DUPA include minoxidil, finasteride, low level laser. Hair transplantation is never an option for most with DUPA. DHT is fairly unreliable and we don't use it to make decisions as to whether to use finasteride or not. If you had side effects with saw palmetto, it is certainly possible a person might have side effects with finasteride. However, this can't be dealt with properly over the internet. Be sure to see a physician for a comprehensive review and confirmation of the diagnosis. You can discuss options, including whether finasteride is right for you or not. 

It sounds like you may have DUPA. You need to be investigated and examined by a dermatologist for diagnosis and treatment. Many with DUPA will respond to finasteride.