Mutagenicity testing of 3 hallucinogens: LSD, psilocybin and delta 9-THC, using the micronucleus test.

Using the micronucleus test as a screening method for mutagenic activity, no significant increase in the number of micronuclei was found when LSD, psilocybin or delta 9-THC were administered in 3 logarithmically increasing doses to mice, Azathioiprine (Imuran), given as a positive control, caused a statistically significantt increase in the micronucleated cells.