here's the listing of states where it can be purchased OTC, either directly OTC or with a standing physicians order where it will be prescribed on the spot, at certain prominent pharmacy chains (i believe they are still working to expand the program to cover all 50 states):
Pharmacy Chain A
* Arkansas * California * Connecticut
* Indiana * Kentucky * Maryland
* Massachusetts * Minnesota * Mississippi
* Montana * New Hampshire * New Jersey
* New York * North Carolina * North Dakota
* Ohio * Pennsylvania * Rhode Island
* Tennessee * Utah * Vermont
* Virginia * Wisconsin
Pharmacy Chain B
* Alabama * Arkansas * California
* Colorado * Connecticut * District of Columbia
* Idaho * Illinois * Indiana
* Kentucky * Louisiana * Maine
* Maryland * Massachusetts * Minnesota
* Mississippi * Montana * Nebraska
* New Hampshire * New Jersey * New Mexico
* New York * North Carolina * Ohio
* Oklahoma * Oregon * Pennsylvania
* Rhode Island * South Dakota * Tennessee
* Texas * Utah * Vermont
* Virginia * Washington * Wisconsin
as long as you're in one of the states listed, you're either already able to carry around naloxone without a script or you will be given a prescription for it on the spot, so there shouldnt be anything to worry about legally.