AbstractTobacco flavors increase the attractiveness of a tobacco brand and ultimately promote addiction. Information about what flavor and how much flavor is in flavor capsules can provide an effective way to regulate tobacco flavor. In this study, 128 flavor chemicals were identified and quantified by gas chromatography–mass spectrometry using libraries and authentic standards. Validation of the developed method was performed for interference, detection limits, calibration curves, accuracy, and precision. Menthol was the main ingredient in all capsules, and the carcinogenic pulegone was detected. Detected menthofuran, benzyl alcohol, geraniol, and eugenol cause toxic or severe irritation, and detected lactones can increase nicotine addiction by inhibiting nicotine metabolism in smokers. Margin of exposures for carcinogenic pulegone and non‐carcinogenic menthol were well below safety thresholds, indicating a significant risk of inhalation exposure. It is desirable to prohibit the use of flavor capsules in consideration of human risk.