Subjects char-acterized by very high taste-thresholds for 6-n-propylthiouracil and quinine also display high taste thresholds for a wide variety of chemically unrelated compounds, such as chlorpromazine, psilocybin, sodium chloride, etc., etc. whereas a combination of low thresholds for 6-n-propylthiouracil and quinine is characteristic for subjects with low thresholds for a wide variety of other compounds. The saliva of subjects with very high taste-thresholds for 6-n-propylthiouracil ("non-tasters") oxidizes in vivo certain compounds, e.g. chlorpromazine, at a faster rate than the saliva of (sensitive) tasters of 6-n-propylthiouracil. The possibility that the reported two ranges of taste sensitivity may (1) also express systemic differences in drug responsiveness and (2) be a factor involved in the relation between taste thresholds and food dislikes, is discussed.