Rolling Stone reports on the safety of vaping the common sleep aid melatonin.

When concentrated melatonin is inhaled, in theory, it is instantly absorbed by alveoli in the lungs and enters the bloodstream, instead of being metabolized by the liver, as would a tablet. Only a small amount of melatonin, then, is required to create a physiological effect. But Dr. Philip Forys, a pulmonologist at Indiana University, is skeptical about vaped melatonin’s proposed absorption rates. “Melatonin is a large chemical compound, unlike nicotine and other commonly vaped substances,” Dr. Forys tells Rolling Stone. “While it’s possible this product may work, we really don’t know if this is an efficient delivery mechanism, as there have been no studies conducted on the effects of vaping melatonin.”