I works great when you have this "thinking in your sleep and wake up even more tired" syndrome.

Melatonin related supplemements helps you relax quickly and really sleep deep. I personally found that taking 1/3 of recommended dose works perfectly. Taking full doze making me wake up in such a limb state - that it takes me literally one hour for muscles to get back into their ability to move the body.

Another thing is that I found that taking it for a week or two (no more) is optimal. Few cycles of deep, relaxed sleep are enough for body/mind to get into relatively better balance than before.

Adding regular physical exercise to the mix helps to reignite the whole system back.