LSZ, or lysergic acid 2,4-dimethylazetidide, is a synthetic lysergamide related to LSD. Its amide group contains a four-membered azetidine ring with two methyl substituents. LSZ appeared on the research-chemical market in 2013 and has been analytically characterised in powder and blotter products. Animal studies show LSD-like behavioural activity, but controlled human research remains limited.
Chemistry and stereochemistry
LSZ retains the ergoline skeleton of LSD, but replaces the N,N-diethylamide group with a 2,4-dimethylazetidide ring. The two methyl-bearing positions create stereochemical features that are important for the compound’s identity. Analytical studies have focused on the (2′S,4′S) form reported in commercial samples.
A 2017 paper characterised LSZ tartrate using NMR, GC-MS, high- and low-resolution mass spectrometry, HPLC and infrared spectroscopy. The authors also developed methods to identify the compound in blotter paper (Brandt and colleagues, 2017).
Pharmacology
LSZ produces LSD-like effects in animal drug-discrimination and head-twitch models. In the mouse head-twitch response assay, its ED50 was 114.2 nmol/kg, compared with 132.8 nmol/kg for LSD in the same study. The authors therefore described LSZ as approximately equipotent to LSD in that specific model. This result cannot be translated directly into a human potency estimate.
The behavioural findings are consistent with serotonergic psychedelic activity, particularly through 5-HT2A receptor signalling. However, a complete modern receptor profile for LSZ has not been established.
Reported effects
Most human accounts are anecdotal and draw comparisons with LSD. Reports mention changes in visual perception, thought and mood, but there are no controlled studies that establish a consistent subjective profile or frequency of adverse reactions.
Clinical evidence and limitations
LSZ has been identified in blotter and powder products, but its human pharmacokinetics and clinical toxicology remain poorly characterised. There is no reliable concentration-toxicity relationship, and dependence potential and long-term effects have not been adequately studied.
The analytical characterisation and animal behavioural study remain the strongest sources of direct evidence. The behavioural findings confirm biological activity, without establishing clinical safety.
Related lysergamides
LSZ is related to LSD, MiPLA, AL-LAD and ETH-LAD. Its dimethylazetidide amide is the main structural feature that distinguishes it from the more common diethylamide lysergamides.
