LSM-775, also known as N-morpholinyllysergamide or as lysergic acid morpholide, is a psychedelic drug of the lysergamide family related to lysergic acid diethylamide (LSD).
LSM-775 is less potent than LSD but is reported to have some LSD-like effects at doses ranging from 75 to 1,000üg orally and a shorter duration. It may only produce weak or threshold psychedelic effects in humans. There have been said to be fewer signs of cardiovascular stimulation and peripheral toxicity with LSM-775 compared to LSD. On the other hand, more recent reports suggest that LSM-75 produces considerable nausea and feelings of lethargy and sedation.
LSM-775 is a potent full agonist of the serotonin 5-HT<sub>1A</sub> receptor and a potent partial agonist of the serotonin 5-HT<sub>2A</sub>, 5-HT<sub>2B</sub>, and 5-HT<sub>2C</sub> receptors. It does not produce the head-twitch response, a behavioral proxy of psychedelic effects, in rodents. However, LSM-775 can robustly increase head twitches if it is coadministered with the serotonin 5-HT<sub>1A</sub> receptor antagonist WAY-100635. These findings indicate that serotonin 5-HT<sub>1A</sub> receptor activation suppresses the psychedelic-like effects of LSM-775.
The chemical synthesis of LSM-775 has been described.
Analogues of LSM-775 include the cyclized lysergic acid piperidide (LA-Pip), lysergic acid azepane (LA-Azepane), lysergic acid pyrrolidide (LA-Pyr; LPD-824), lysergic acid pyrrolinide (LPN), and lysergic acid 2,4-dimethylazetidide (LA-Az, LSZ) and the non-cyclized LEO, LA-MeO, ergometrine, and methylergometrine, among others.
LSM-775 was first described in the scientific literature by Albert Hofmann and colleagues by 1955. It emerged as a novel designer drug in 2013.
LSM-775 is not a controlled substance in Canada as of 2025.
LSM-775 is not an explicitly controlled substance in the United States. However, it could be considered a controlled substance under the Federal Analogue Act if intended for human consumption.