Electronic cigarettes have recently gained popularity on claims of their ability to provide smokers with the stimulation they crave and none of the health risks, but a new warning issued by the Food and Drug Administration has called those claims into question, stating that they may be as harmful as real cigarettes.

The FDA has labored for months to ban the sale of e-cigarettes within the U.S., so far meeting with resistance from distributors and defiance from consumers.

HealthNews reports that the FDA has this far been unable to ban the sale of these devices due to a dispute regarding their jurisdiction, but the agency nonetheless held a news conference in which they revealed that e-cigarettes emit nicotine, carcinogens and in one case chemicals found in antifreeze.

In addition to FDA personnel, prominent doctors spoke at the conference, some of whom said that these devices do not help smokers quit the harmful habit, and that they provide no real health benefits.

Smokers who would like to quit have several options that could be safer than e-cigarettes. Supplements like St. John’s Wort and ginseng have been included in successful smoking-cessation plans, while acupuncture and hypnotherapy have also proven useful to some.