Is it legal to mail prescription drugs using the US Postal Service?!

Is it legal to mail prescription drugs using the US Postal Service?

My nephew went on vacation and forgot his Zyrtec pills (for his allergies), so I mailed them to him in a regular envelope by US Postal First Class Mail. It's been over a week and he hasn't gotten them yet. Is it possible that they've been confiscated? Wouldn't they try to contact me (my return address was on the envelope) if that was the case?

3 weeks ago
Sorry, it was w/in the US. The next state over in fact. usually it takes 3 days.

You must be a medical doctor, drug company, pharmacy or other 'authorized dispenser' to mail prescription medications. See USPS Domestic Mail Manual (Section 601.11.11) You can do a search and find out more information.

You can take the chance and mail them, but there is a chance they will be confiscated and destroyed.