Would security unseal a bottle of melatonin?

Landed in Japan for the first time today, and noticed that my bottle of melatonin I got off of Amazon has the security seal torn apart and opened. I now am a little paranoid because I don’t know if security opened my checked bag and checked the melatonin, or if it came like that from Amazon and I shouldn’t be consuming it. Does Japanese security ever go through bags and look for things/open things? Everything looked like it was in the same place I left it when I packed