"for insomnia i think it helps, 1mg to 3mg depending on each one&#039;s body. but if you don&#039;t get to sleep properly, maybe anxiety is the cause. in my case and from my life experience, i do some tricks to beat both anxiety and insomnia:  1.5mg melatonin 30min before bed time; spend those 30min reading a book (out of the bedroom) with just 5w blue-light; take 75mg trazodone when already in bed, just before program my alarm-clock, lights out; always get up before 9am (no matter what); exercise outdoors 40min (before lunch time ); have 2 hobbys: listen to music (without headphones) and study collective sports; dinner time before 8:30pm; and psychotherapy 2 times a month, forever. 
so: melatonin is a part of a whole."