In preparation for a trial on co-prescription of inhalable heroin and methadone, two methods for inhalation of heroin/caffeine tablets were compared: the commonly used method of 'chasing the dragon' and a standardised procedure for inhalation of volatilised heroin, using a heating device. Five male addicts inhaled a tablet of smokable heroin daily for 5 days, alternating the inhalation method. Plasma concentrations of heroin, 6-acetylmorphine, morphine and morphine-3- and -6-glucuronide were determined using a liquid chromatography method with tandem mass spectrometric detection. The exposure to heroin and its metabolites (expressed as areas under the concentration-time curve) was significantly lower after smoking via the heating device than after 'chasing the dragon': heroin 80% and 6-acetylmorphine 73% lower (p<0.05). Maximal concentrations of heroin and 6-acetylmorphine were also 80% and 70% lower (p<0.05) after using the heating device. 'Chasing the dragon' is a more efficient inhalation method than inhalation via the heating device.