Updated

The Coca-Cola Co. (KO) plans to put caffeine content on the labels of its drink products distributed in the United States. The Atlanta-based company on Wednesday said that the plan is voluntary and part of an industry initiative.

Coca-Cola said it already has included caffeine labeling on its Full Throttle and Enviga products. It said it will roll out the new labels on its other brands, starting with cans of Coca-Cola Classic in May and expanding to other brands and packages during the remainder of the year.

The time at which the revised labels reach store shelves will vary by brand and by region as U.S. bottlers use up existing inventories of packaging.

A spokeswoman for Coca-Cola's North America division said the expanded caffeine labels will not be placed on Coke products distributed outside the United States.