Just one look at the name and you'll know the two main ingredients of Coca-Cola. The leafs of the cocaplant from South America, and the African kolanut, which is very rich of caffeine. To avoid misunderstandings: chemists agree that the last trace of cocaine was removed from the drink in 1903. But until the late thirties, The Coca-Cola Company had to defend itself in court of law against anti-drugs activists. The exact formula has always been a mystery. It is said that only two top-chemists in the company know the exact formula at the same time. It is also said that in the complete history of Coca-Cola only 8 people ever knew it.. and only two of them are still alive...

When people speak of "The Secret Formula" they actually mean the ingredient called "7X", a mixture of fruit-oils and spices that gives the syrup its specific taste. It seems to be very important to the Coca-Cola Company to keep its formula secret. When the Indian government in 1977 demanded to reveal the formula, the company said rather to pull itself back from this gigantic market than to reveal its secret.

Lots of other companies tried to imitate Coca-Cola, but in the end, only Pepsi Cola appeared to be a serious competitor. In the thirties, Pepsi really became a serious rival, because they decided to sell their drink in a bottle that was twice as big as the Coca-Cola bottles, but at the same price (5 dollarcents).

One of the most sensational moments in its history owes Coca-Cola to Pepsi. In 1982 The Company decided to radical change the secret formula for the first time in their history. The public seemed to prefer a sweeter and softer taste than the authentic taste of Coca-Cola. The chemist got to work and invented a new drink: New Coke, which was proudly presented as the modern successor of Coca-Cola.
Now THAT was a mistake... The American people demanded their old and trusted Coke back. The Company was overloaded by letters and calls. New Coke didn't sell... A few months after its introduction, the management decided to stop producing New Coke and to go on with the old Coke.
In a press conference Coca-Cola's chairman apologized to the American people. The original Coca-Cola returned under the name Coca-Cola Classic. New Coke disappeared so fast that it never even made it to other countries.

In 1994 an author named Mark Pendergrast wrote a book entitled "For God, Country and Coca-Cola". He was able to interview alost everyone within the Company and then he discovered a small book called: "Account and Formula book belonging to Dr. J.S. Pemberton while a druggist in Columbus". In this book he found the original formula to Coca-Cola.

Because I got most of the information above from a very good site about the formula, I decided not to copy the entire page, but to link it here. All credits go to the person who wrote this page.
More about the formula can be found at this page:
Coca-Cola Formula
(thanx to the author, keep up the good work)