Section 910(g) of the Federal Food, Drug, and Cosmetic Act (FD&C Act) (21 U.S.C 387j(g)) gives FDA the authority to issue regulations to exempt tobacco products intended for investigational use from the requirements of Chapter IX of the FD&C Act, including premarket submission requirements. To date, FDA has not issued such regulations, and consequently investigational tobacco products are not exempt from FD&C Act requirements, including premarket submission requirements. This draft guidance describes FDA's current thinking regarding the definition of "investigational tobacco product" and discusses the kind of information FDA intends to consider in making enforcement decisions regarding the use of investigational tobacco products until regulations are issued and become effective or FDA provides written notice of its intent to change its enforcement policy. FDA has issued two other draft guidances that discuss investigational tobacco products: Applications for Premarket Review of New Tobacco Products (September 2011); and Modified Risk Tobacco Product Applications (March 30, 2012). When finalized, this guidance will reflect FDA's most detailed recommendations on the use of investigational tobacco products.