It occludes dentinal tubules, helping reduce dentin hypersensitivity. It's a tooth-desensitizing agent helping people who are for example, very sensitive to very cold/hot temperature in their mouth.

There is evidence that it can foster enamel/dentin mineral gain, but head to head studies shows that it's comparable to regular fluoride toothpaste and not superior. E.g. In a randomized in-situ trial (Caries Research, 2017), adding 5% NovaMin to a 927-ppm SMFP toothpaste did not improve remineralization outcomes vs the same fluoride formula without NovaMin.

Also, you can find NovaMin in the US (e.g., NUPRO Sensodyne Prophylaxis Paste with NovaMin).