I'm Dutch and live here. But my wife is American. If I ever happen to live in the US (chances are there in my lifetime). I'm going to employ this strategy.
I don't trust the US with this and the Netherlands has proven itself to me in this sense. There are probably many more European countries that do this well. I'm simply not changing a winning team.
But I'd love to hear from other people that believe they found a good melatonin supply in a country. I'm curious.