A new report showing that teens are using electronic cigarettes now more than ever has some doctors worried.

It's often billed as a safer alternative to cigarettes, but the new numbers are surprising even the experts. The Centers for Disease Control says in just one year, the number of teens using e-cigarettes has tripled.

E-cigarettes,or "vaporizers," don't use tobacco, but they do contain nicotine.

News 12 Connecticut spoke to health experts Friday who say e-cigarettes may taste good and smell better, but customers still don't know always what chemicals are inside.