The Food and Drug Administration has released a long-awaited draft of suggested guidelines for dietary supplement manufacturers that are seeking to introduce new ingredients into the marketplace. The document marks one of the first substantial actions by the FDA’s newly created Office of Dietary Supplement Programs. Steven Tave, the acting director of that office, has called it “an important step forward” in the effort to protect consumers from potentially dangerous supplements.

The current rule, in place since the 1994 passage of the Dietary Supplement Health and Education Act (DSHEA), requires supplement manufacturers to notify the FDA at least 75 days before bringing a new dietary ingredient, or NDI, to market and to provide evidence that the new ingredient can reasonably be expected to be safe.

This NDI rule is the FDA's primary tool to identify and block unsafe supplement ingredients before they are made available to consumers.  

But critics say that rule is full of loopholes:

• Any chemical that already exists in the food supply in some form is exempt from the rule, even if the supplement maker is using it in a new, potentially dangerous way (think pure powdered caffeine).

• Compliance with the NDI rule has been consistently dismal. With more than 90,000 dietary supplements on the market, and some 5,560 new ones being introduced every year, the agency has received fewer than 1,000 new-ingredient notifications in the past 20 years.

• Ingredients that were submitted for NDI approval by one company but rejected by the FDA, have sometimes turned up in products being sold by other companies, including sheep placenta and the mushroom extract Agaricus blazei.

“We need much tighter control of what’s going into the products,” says Chuck Bell, programs director for Consumers Union, the policy and advocacy arm of Consumer Reports.

The FDA produced the first draft of NDI guidance in 2011, in response to a congressional order that the agency clarify both the definition of a new dietary ingredient and the safety requirements such ingredients would be subject to.

That draft was hotly contested by both the supplement industry and its critics. The industry argued that the proposed rules were excessively burdensome, while critics pointed to more loopholes, including one that allowed supplement makers to simply exempt their own ingredients, by "self-affirming" their safety.

The revised draft guidance released today—a 102-page document, that industry and watchdog groups are still combing through—focuses on clarifying for manufacturers when, exactly, an ingredient falls under the NDI rule.

But critics warn that dangerous loopholes have yet to be addressed by the agency, and that no draft-guidance can fully close them. “We will still need aggressive oversight to track down all the unsafe ingredients that have already made their way into the supplements supply," says Bell.