N.H. Rev. Stat. Ann. § 318-B:6

Possession of or control of controlled drugs obtained as authorized shall be lawful if in the regular course of business, occupation, profession, employment, or duty of the possessor. A person who obtains controlled drugs under the provisions of RSA 318-B:5 or otherwise shall not administer, dispense, or otherwise use such drugs within the state, except within the scope of his employment or official duty, and then only for scientific or medical purposes and subject to the provisions of this chapter.