The FDA knows nicotine is addictive. It wants to regulate it for the first time

The FDA hopes that a new limit on nicotine levels in cigarettes will help people stop smoking or avoid the habit altogether. (Paul J. Richards/AFP via Getty Images)

The Food and Drug Administration has called cigarettes "the only legal consumer product that, when used as intended, will kill half of all long-term users."

But the agency has never regulated nicotine, cigarettes' notoriously addictive ingredient — and for years, it has been wanting to change that. Now, it seems, the time has come.