As one who has suffered from chronic insomnia, off and on for years, and done a TON of research on all these supplements, I personally would not mess around with any off them. Except for possibly melatonin, and that in much smaller doses than usually given (<1mg). 4-amino-3-phenylbutyric acid (Phenibut) in particular has a terrible reputation--Please be careful with that stuff! You can get wicked rebound insomnia from using this and other supplements, and other unpleasant side effects. Very few people get consistently good results over time with any of these.

Eat a good diet, get good exercise, reduce stress. Realize that you can function on little or no sleep if absolutely necessary, and it won't kill you(even if you feel awful), so there is no good reason to lie in bed and fret about it. Hormone supplementation has been the most helpful for me in the long run.