Speed of absorption and elimination of an antimotion sickness drug sets limits on the protection afforded. The aim of this experiment was to determine whether a well proven antimotion sickness drug--scopolamine (hyoscine)--could be absorbed more rapidly from buccal tablets than from the standard issue ingested tablets. Plasma scopolamine levels were measured using a radioreceptor assay of repeated blood samples from 10 volunteers, each of whom took buccal and standard ingested tablets (both 0.6 mg scopolamine hydrobromide) on two different occasions, and from a further 8 volunteers following ingestion of a pharmacy-prepared scopolamine capsule (0.6 mg scopolamine hydrobromide). There was no statistically significant speed advantage for the buccal tablet (mean time to peak levels approx 50 min). Individual variation in the speed of scopolamine absorption and rate of elimination (mean half-life approx 170 min) was great. This may account for failure of motion sickness protection in some individuals.