The agency said it is looking into recent studies showing the chemical triclosan can alter hormone levels in animals. Other studies suggest the chemical increases bacterial resistance to antibiotics.
The FDA says it currently has no evidence that triclosan is hazardous to humans and does not recommend consumers avoid it. However, the agency said there is no evidence that soap with triclosan is superior to soap without the ingredient.
The agency plans to release its review of the chemical next year.
FDA scientists last studied the chemical in 1997 and concluded it helped enhance toothpaste.