NRS 453.411: Unlawful use of controlled substance; penalty.

1. It is unlawful for a person knowingly to use or be under the influence of a controlled substance except in accordance with a lawfully issued prescription.

2. It is unlawful for a person knowingly to use or be under the influence of a controlled substance except when administered to the person at a rehabilitation clinic established by the Division of Public and Behavioral Health of the Department or licensed by the Health Care Purchasing and Compliance Division of the Nevada Health Authority, or a hospital licensed by the Health Care Purchasing and Compliance Division.

3. Unless a greater penalty is provided in NRS 212.160, a person who violates this section shall be punished for a misdemeanor.