No person may knowingly ingest a controlled drug or substance or have a controlled drug or substance in an altered state in the body unless the substance was obtained directly or pursuant to a valid prescription or order from a practitioner, while acting in the course of the practitioner's professional practice or except as otherwise authorized by chapter 34-20B. A violation of this section for a substance in Schedules I or II is a Class 5 felony. A violation of this section for a substance in Schedules III or IV is a Class 6 felony.
SDCL 22-42-5.1