Quipazine has been sitting in the pharmacology literature since the 1960s as a compound that almost worked. It behaves like a classic psychedelic in animals and was once investigated as an antidepressant, but it also upsets the stomach, and in human testing, that ceiling arrived before any psychedelic effect did.
Chemists at Virginia Commonwealth University decided the problem was structural rather than fundamental. Their answer, a molecule called VCU-1012, was described in Science Signaling and represents an unusual engineering goal: to build a drug that acts on the brain while deliberately ignoring a receptor in the digestive tract.
