Methysergide, UML-491, or 1-methyl-d-lysergic acid butanolamide, is a prescription drug closely related to LSD, and is used to treat migranes. It is sold under the names of Sansert and Deseril in 2mg dosages. Like LSD, methysergide also produces psychedelic and hallucinogenic effects. The threshold dosage for psychedelic effects is 4.3mg. Full effects are felt with dosages of 8-20mg.
- Children's Reactions to Psychotomimetic Drugs by L. Bender