LSD Blotter Paper Art

A single dose of LSD may be between 100 and 500 micrograms—an amount roughly equal to one-tenth the mass of a grain of sand. Threshold effects can be felt with as little as 25 micrograms of LSD. Dosages of LSD are measured in micrograms (µg), or millionths of a gram. By comparison, dosages of most drugs, both recreational and medicinal, are measured in milligrams (mg), or thousandths of a gram. For example, an active dose of mescaline, roughly 0.2 to 0.5g, has effects comparable to 100 µg or less of LSD.
Typical doses in the 1960s ranged from 200 to 1000 µg while street samples of the 1970s contained 30 to 300 µg. By the 1980s, the amount had reduced to between 100 to 125 µg, lowering more in the 1990s to the 20–80 µg range , and even more in the 2000s.
Estimates for the lethal dosage (LD50) of LSD range from between 200 µg/kg to more than 1 mg/kg of human body mass, though most sources report that there are no known human cases of such an overdose. Other sources note one report of a suspected fatal overdose of LSD occurring in November 1975 in Kentucky in which there were indications that ~1/3 of a gram (320 mg or 320,000 µg) had been injected intravenously. (This is a very extraordinary amount, particularly when compared to the average LSD dosage of ~100 µg). Experiments with LSD have also been done on animals; in 1962, an elephant named Tusko died shortly after being injected with 297 mg, but whether the LSD was the cause of his death is controversial (due, in part, to a plethora of other medicines administered simultaneously).