Now, let me explain the reason this is my suggestion: Valerian root is known as "Nature's Valium" is a potent otc sedative. In low doses during the day, it helps with irritability and aggression. In larger doses it induces a deep dream free sleep. However, most medication induced insomnia doesn't respond to it or other OTC methods as individual medications. When you add Valerian root and melatonin together, it has a compounding effect. It doesn't induce sleep the same way that a prescription sleeping pill will, it just makes you feel relaxed and sleepy. This combination reliably gets results, but is mild enough in its actions that you don't feel like you've taken something to make you sleep.
So for those of you for whom the melatonin isn't enough, try adding Valerian Root. It's available in 500mg veg capsules for less than $10 for 90 capsules.