From Wikipedia

Coca — Cocaine

Pemberton called for five ounces of coca leaf per gallon of syrup, a significant dose; in 1891, Candler claimed his formula (altered extensively from Pemberton's original) contained only a tenth of this amount. Coca-Cola did once contain an estimated nine milligrams of cocaine per glass, but in 1903 it was removed.[25] Coca-Cola still contains coca flavoring.

After 1904, instead of using fresh leaves, Coca-Cola started using "spent" leaves—the leftovers of the cocaine-extraction process with cocaine trace levels left over at a molecular level.[26] To this day, Coca-Cola uses as an ingredient a cocaine-free coca leaf extract prepared at a Stepan Company plant in Maywood, New Jersey.

In the United States, Stepan Company is the only manufacturing plant authorized by the Federal Government to import and process the coca plant.[27] Stepan laboratory in Maywood, New Jersey is the nation's only legal commercial importer of coca leaves, which it obtains mainly from Peru and, to a lesser extent, Bolivia. Besides producing the coca flavoring agent for Coca-Cola, Stepan Company extracts cocaine from the coca leaves, which it sells to Mallinckrodt, a St. Louis, Missouri pharmaceutical manufacturer that is the only company in the United States licensed to purify cocaine for medicinal use.[28] Stepan Company buys about 100 metric tons of dried Peruvian coca leaves each year, according to Marco Castillo, spokesman for Peru's state-owned National Coca Co.[29]