I am taking Finax 1mg twice a day. Is that okay to treat hair loss? Should I reduce dosage or continue?

Speak to your doctor who prescribed you the medication about changing the doses. You need to follow your doctors recommendation.

Finasteride has been shown in many studies to be beneficial in treating hair loss from androgenic alopecia.  However the recommended dosage is 1 mg daily not twice daily.   There is not a proven benefit from taking more and the increased dose could actually be harmful. 

Finasteride is FDA approved for the treatment of male pattern balding (also called androgenetic alopecia) at a dose of 1 mg daily.Clinical studies for male balding have not shown higher doses to be more effective.

and it should be taken daily not more than that. The higher doses will not necessarily benefit you but might increase the sexual side effects of the drug.