Prohibited substances By 81st Training Wing Public Affairs Department of Defense employees are subject to prosecution for the consumption or possession of certain substances. Knowing your restrictions and knowing your resources can prevent you from finding yourself in trouble for illegal drug use. Federal law supersedes state law for all DoD employees when determining whether a substance is prohibited. Resource - Operational Supplement Safety - DoD has released an instruction outlining the use of dietary supplements and substances and an online database allowing service members to reference prohibited ingredients. Check here for specific ingredients that are prohibited for service members.