Title 21 has 26 chapters:

• 21 U.S.C. ch. 1 — Adulterated or Misbranded Foods or Drugs (§§ 1—26)
• 21 U.S.C. ch. 2 — Teas (repealed) (§§ 41–50)
• 21 U.S.C. ch. 3 — Filled Milk (§§ 61–64)
  • Filled Milk Act
• 21 U.S.C. ch. 4 — Animals, Meats, and Meat and Dairy Products (§§ 71–149)
• 21 U.S.C. ch. 5 — Viruses, Serums, Toxins, Antitoxins, and Analogous Products (§§ 151–159)
• 21 U.S.C. ch. 5A — [Bureau of Narcotics] (omitted) (§§ 161–165)
  • former Federal Bureau of Narcotics
• 21 U.S.C. ch. 6 — [Narcotic Drugs] (repealed or transferred)
• 21 U.S.C. ch. 7 — Practice of Pharmacy and Sale of Poisons in Consular Districts in China
• 21 U.S.C. ch. 8 — Narcotic Farms (repealed)
• 21 U.S.C. ch. 9 — Federal Food, Drug, and Cosmetic Act
• 21 U.S.C. ch. 10 — Poultry and Poultry Products Inspection
  • Poultry Products Inspection Act of 1957
• 21 U.S.C. ch. 11 — Manufacture of Narcotic Drugs (repealed)
• 21 U.S.C. ch. 12 — Meat Inspection
  • Meat Inspection Act of 1906
• 21 U.S.C. ch. 13 — Drug Abuse Prevention and Control
  • Controlled Substances Act, a part of the Comprehensive Drug Abuse Prevention and Control Act of 1970.
• 21 U.S.C. ch. 14 — [Alcohol and Drug Abuse Educational Programs and Activities] (repealed)
• 21 U.S.C. ch. 15 — Egg Products Inspection
• 21 U.S.C. ch. 16 — Drug Abuse Prevention, Treatment, and Rehabilitation
• 21 U.S.C. ch. 17 — [National Drug Enforcement Policy] (repealed)
• 21 U.S.C. ch. 18 — Presidents Media Commission on Alcohol and Drug Abuse Prevention
• 21 U.S.C. ch. 19 — Pesticide Monitoring Improvements
• 21 U.S.C. ch. 20 — National Drug Control Program
• 21 U.S.C. ch. 21 — Biomaterials Access Assurance
• 21 U.S.C. ch. 22 — National Drug Control Policy
  • Office of National Drug Control Policy
• 21 U.S.C. ch. 23 — [National Youth Anti-Drug Media Campaign] (repealed)
• 21 U.S.C. ch. 24 — International Narcotics Trafficking
• 21 U.S.C. ch. 25 — Miscellaneous Anti-Drug Abuse Provisions

• Title 21 of the Code of Federal Regulations - Food and Drugs

• U.S.C Title 21, via Cornell Law School Legal Information Institute (as above)
• U.S.C. Title 21, via United States Government Printing Office