Only 12 of the 15 volunteers had sufficient plasma levels of DMT to permit pharmacokinetic measurements, possibly due to early emesis during the course of the session. Of these, the maximum plasma concentration (Cmax) (15.8 ng/ml) occurred at 107 minutes after ingestion, while the half-life (T1/2 was 259 minutes. THH was measured in 14 of the 15 subjects; the Cmax was 91 ng/ml, reached at 174 min. This compound displayed a prolonged half-life of 532 minutes, in contrast to harmine which had a half-life of 115.6 min. The Cmax for harmine and harmaline was 114.8 and 6.3 ng/ml, respectively, and time of maximum concentration (Tmax) was 102 and 145 minutes, respectively. The T1/2 for harmaline could not be measured (Callaway, et al.,1997).