The Controlled Substances Act (CSA), part of the Comprehensive Drug Abuse Prevention and Control Act of 1970, is the legal cornerstone of the government’s war against drug abuse. Drug Enforcement Administration (DEA) has divided these substances into five categories, called “schedules,” based on each drug’s (1) potential for abuse, (2) safety, (3) addictive potential and (4) whether or not it has any legitimate medical applications. Schedule 1 (I) Drugs Schedule 1 (I) drugs, substances, or chemicals are defined by the federal government as drugs with no currently accepted medical use and a high potential for abuse. Schedule 1 (I) drugs are the most dangerous drugs of all the drug schedules with potentially severe psychological or physical dependence.
Schedule I Drugs
Examples of Schedule 1 (I) Drugs: • Heroin • Lysergic acid diethylamide (LSD) • Marijuana (cannabis)* • Methylenedioxymethamphetamine (ecstasy) • Methaqualone • Peyote Schedule 2 (II) Drugs Schedule 2 (II) drugs, substances, or chemicals are defined as drugs with a high potential for abuse, less abuse potential than Schedule 1 (I) drugs, with use potentially leading to severe psychological or physical dependence. These drugs are also considered dangerous. 
Examples of Schedule 2 (II) Drugs: • Cocaine • Methamphetamine • Methadone • Hydromorphone (Dilaudid) • Meperidine (Demerol) • Oxycodone (OxyContin) • Fentanyl • Dexedrine • Adderall • Ritalin Schedule 3 (III) Drugs Schedule 3 (III) drugs, substances, or chemicals are defined as drugs with a moderate to low potential for physical and psychological dependence. Schedule 3 (III) drugs abuse potential is less than Schedule 1 (I) and Schedule 2 (II) drugs but more than Schedule 4 (IV). Examples of Schedule 3 (III) Drugs: • Combination products with less than 15 milligrams of hydrocodone per dosage unit (Vicodin) • Products containing less than 90 milligrams of codeine per dosage unit (Tylenol with codeine) • Ketamine • Anabolic steroids • Testosterone Schedule 4 (IV) Drugs Schedule 4 (IV) drugs, substances, or chemicals are defined as drugs with a low potential for abuse and low risk of dependence.