It depends on where you live. I´m living in the EU. Parcels from non-EU countries are always checked by customs. Thats why, I would never risk ordering a drug from a non-EU country, especially not N. In my country it´s a criminal offense.
that's not necessarily true.
ive ordered from china several times. sea freight is less likely to be checked. air freight almost always is checked
as long as the right tax is paid there is no real reason for customs to open the box. a drug dog wont smell it and on the x-ray machine it will just look as though its bottles of liquid
i assume the labels are removed. also, to be sure, put someone elses name on the package, not yours. when it gets delivered dont open it! write on the box return to sender and leave it there for a few hours (somewhere in your house) thats your get out of jail free card.
but i doubt they would do a controlled delivery for N, you'd probably just get a love letter from customs