LD50 SOURCES
Clinical Management of Poisoning and Drug Overdose
by Haddad Winchester
page 459:
"No well-documented human deaths resulting directly from the toxic effects of LSD itself have occurred, though LSD has been implicated in accidental deaths, suicides, and homicides. LD50 (That's lethal dose in 50% of those who injest this much) determinations vary widely with species, begin 46 mg/kg in mice, 16.5 mg/kg in rats, 0.3 mg/kg in rabbits and 0.1 mg/kg in elephants. In monkeys, the LD100 is 5 mg/kg. Death in these animals is the result of respiratory failure, preceded in the rabbit by marked hyperthermia. Human data are manifestly lacking, and predictions of the average lethal dose for humans have ranged from 0.2 mg/kg to more than 1 mg/kg, administered orally.
Psychedelics Encyclopedia
Peter Stafford
p.70
"For those concerned about immediate medical hazards in ingesting LSD...Abram Hoffer has estimated, on the basis of animal studies, that the half-lethal human dose--meaning half would die--would be about 14,000 [ug]. But one person who took 40,000 ug survived. In the only case of death reportedly caused by overdose (Journal of the Kentucky Medical Association), the quantity of LSD in the blood indicated that 320,000 ug had been injected intravenously."
Misc References*
by K Trout
Based on the real world murder of lab animals the following results HAVE been published for LD50 studies of LSD-25:
(Please bear in mind that an oral LD50 is commonly 2 or 3X an intravenous LD50)
Mouse (intravenous)
46 mg/ kg (citing Rothlin & Cerletti (1957) Ann. NY Acad. Sci. 66: 668)
65 mg/ kg (citing information provided by Sandoz Pharmaceuticals)
Rat (intravenous)
16.5 mg/ kg (citing Rothlin & Cerletti (1957) above)
I omitted the rabbit figures as rabbits are extremely overly sensitive to all the major hallucinogens except for mescaline and similar. Source for the above was Usdin & Efron (1979) Psychotropic Drugs and Related Compounds (2nd Edition).
Please also note the values above are given as mg/kg of body weight not as simple mg doses. They suggest a human dose, regardless of the route of administration, would be radically greater than 14 mg.
If averaging the low and high values above, the value obtained is ~41 mg/ kg of body weight. Since this is an IV value (& assuming people respond like rodents)an oral LD50 would likely be in excess of 80 mg/kg (Meaning it would take just over 5 grams for someone of my body weight).
Even taking the lowest figure (16 mg/kg) we still wind up with an LD50 of more than a gram of acid for a 65 kg human; even if using the IV figure as an oral one!
If anyone knows where Hoffer derived his figures, we'd love to know.
Related references (taken from p 70 of Stafford's Psychedelic's Encyclopedia):
For the 320 mg of LSD injected intravenously under the mistaken idea it was speed (this killed the user and appears to be the only instance of death by LSD overdose), the reference is: Journal of the Kentucky Medical Association 75: 172-173.
For the dinner party where a bindle of pure crystalline LSD was confused with another one of cocaine and this case of mistaken identity resulted in two fat lines being chopped out and snorted by the 8 people attending: Klock et al. (1975) Clinical Toxicology Volume #8 Issue #2
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