Interpharm ships from SE Asia and packages their products very smartly. BUT, like in any poor country, the postal workers are corrupt and will go through international mail hoping to find money in them. The only reason anybody gets mail sent or received internationally to any of these countries reliably is if it is registered. Because it's registered, and the contents are of no interest to the postal workers, the letter is neatly retaped and sent on. This is a combination of my own experience living in one of those countries and the reply sent to by the contact at interpharm when I first started getting these retaped envelopes months ago.

I'm not saying you shouldn't be cautious, but I have used meds coming from corrupt countries in tampered envelopes many times and never had a problem.