Does a med spa have to register or hold a license in Idaho?

Short answer
The cited rules do not settle this — there is no general med spa license in them; compounding must be tailored to a named patient, and a clinic that sends compounded vials home becomes a prescriber drug outlet, which must register with the board.

Idaho licenses the PREMISES: an “establishment” is a place licensed under the Barber and Cosmetology Services Act, other than a licensed school, where barbering, barber-styling, cosmetology or electrology is practiced — and it is unlawful to practice any occupation licensed, certificated or registered under the chapter in a place or establishment that is not licensed or registered for such practice, except as the chapter specifically authorizes. It is also unlawful for an establishment license holder to employ, or allow to be employed in or about the establishment, a person who is not licensed or certificated under the chapter, UNLESS that person is performing tasks that do not require a license or certificate. The chapter carries its own exceptions, including for licensees serving persons unable by reason of ill health, medical confinement or involuntary incarceration to come to a licensed establishment. The Barber and Cosmetology Services Licensing Board’s fee rule prices the credential as CEILINGS rather than fixed amounts: an individual original license or certificate not to exceed $30 with a $30 application and $30 annual renewal, an instructor license $35, an establishment, dealer or facility license or registration not to exceed $25 with $25 renewal, a school license $360 and $100 renewal, apprentice registration $30, endorsement $45 and reinstatement $35, all non-refundable and aggregable for biennial licensure. The amount actually charged within each ceiling is not surveyed by these claims.