Insomniac for 20 years. What was a complete solution for me was: magnesium, b6 p5p (p5p form very important) and the ultimate punch glycine.

Glycine takes some getting used to, as you will have crazy intense dreams at first. But it is a very safe supplement to take even in large doses.

I always had huge insomnia issues after a physically intensive days after workouts. The stack I settled on solved it. A heavy day just needs a bit more magnesium and quite a bit more glycine.