Cigars may be as bad for your health as cigarettes, particularly among experienced smokers who deeply inhale the toxic substances they contain.

Cigar smokers have elevated levels of potentially cancer-causing ingredients in their blood and urine, a study from the FDA found. The amount of NNAL, a carcinogen which comes only from tobacco, was as high in daily cigar smokers as those who regularly smoke cigarettes, according to the report in Cancer Epidemiology, Biomarkers & Prevention.

While cigar aficionados are supposed to puff rather than inhale, studies show they breathe smoke particles into their lungs even when they think they aren’t inhaling.