Novamin toothpaste is only sold & mfg in the UK. There are some conspiracy theories going around that the ingredient is so good they won't sell it to us in the US! [1]
I actually buy it off Amazon and use it myself because I have teeth sensitivity and it contains no SLS, which causes some irritation for me. It is quite interesting stuff. I doubt it would have lead since a synthetic compound. [2]
And, as Canada is a place, it has Novamin-based Sensodyne.