Chromosomal abnormalities were significantly more frequent in leukocytes from LSD-25 users (six out of eight) than in nonuser controls (one out of nine). The two users without damage had the lowest estimated average dose. Damaged cells were observed in samples taken between 1 day and 6 months after the last dose.
People who use LSD have more chromosomal abnormalities in their white blood cells than non-users. Children exposed to LSD before birth also show higher rates of chromosome breakage. However, the amount of drug taken per dose, the number of doses, or the total dosage did not correlate with how often breaks occurred.