Smokers will soon know better what they're breathing into their lungs.
Beginning in June, cigarette makers must tell the Food and Drug Administration the ingredients in their products.
It's part of new authority given to the FDA last year.
The agency must keep much of the information confidential but will publish a list of harmful or potentially harmful ingredients by mid-year next year.
Tobacco companies acknowledge adding additives like cocoa or coffee to improve the taste.
Some companies already list some of the ingredients on their Web sites.