Drug may refer to:

• Alcohol
• Cigarettes
• Clonazepam
• Heroin
• Locke's drug
• Marijuana
• Oxycodone
• Vaccine
• A4993-E3, which Juliet administered to her sister, Rachel
• The Apollo Candy Company, in The Lost Experience, a company said to create a product which may contain psychotropic ingredients
• The unknown substance dripped by IV into Karl in Room 23
• The pills Jack discovered in his father's empty hotel room in "White Rabbit"
• Shannon's asthma inhaler, which Sawyer claimed he did not have in "Confidence Man"
• The sedative Rousseau used on Sayid in "Solitary"
• The liquid from the canteen that Ethan gave Claire in "Maternity Leave"
• The packet of drugs found by Miles in Mrs. Gardner's grandson's bedroom
• The substance used in tranquilizer darts
• The tranquilizer mixed in a glass of orange juice administered by Ethan to Juliet in "One of Us"

• The same sedative mixed with orange juice given to the passengers of the Galaga in "The Incident, Part 1"

• Hurley's "horse tranquilizer" in "Dave"
• DHARMA Ibuprofen, as seen in the Barracks infirmary
• The hallucinogen given to Sayid by Oldham in "He's Our You"
• The medicine that Ricardos kills a doctor for, to save his wife Isabella. "Ab Aeterno"