LSZ (Lysergic acid 2,4-dimethylazetidide)
LSZ is a structural analogue of LSD in which the diethylamide is replaced by a constrained 2,4-dimethylazetidide ring. It is a potent 5-HT2A agonist producing an LSD-like psychedelic experience, studied preclinically as a probe of lysergamide structure-activity but never in clinical trials.
01 Overview
LSZ (also called lambda) was described in academic structure-activity work on rigidified lysergamides, where locking the amide into an azetidine ring probes how the amide geometry interacts with the serotonin receptor. It is sold as a research chemical in blotter, tartrate microdot and solution form.
User reports describe effects broadly similar to LSD, sometimes with a slightly shorter duration and a more "pushy" or physically stimulating character. There is no human clinical data; potency and duration are anecdotal and derived from receptor binding studies in vitro and in animals.
02 Mechanism
Partial agonist at 5-HT2A and related serotonin receptors; the constrained azetidide ring fixes the amide orientation while retaining high receptor affinity.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Threshold | 10–25 mcg | Sublingual | Microdose range. |
| Common | 75–150 mcg | Sublingual | Full psychedelic dose; broadly LSD-comparable. |
| Strong | 150–250 mcg | Oral | Strong visuals; more stimulating than LSD per reports. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Psychedelic visualsGeometric and colour visuals reported as crisp and LSD-like. | 6-10 h | Anecdotal | |
| Stimulation and energyUsers often describe LSZ as more physically stimulating than LSD. | Anecdotal | ||
| Anxiety at high dosesOverwhelm, paranoia or difficulty relaxing, more likely at strong doses. | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Sympathomimetic stimulationElevated heart rate and blood pressure, tremor and restlessness. | Mild | Common | Anecdotal | |
| Acute psychological distressAnxiety, paranoia or a difficult experience during acute effects. | Moderate | Common | Anecdotal | |
| Persistent perceptual changes (HPPD)Lasting visual disturbances, a recognised risk of LSD-type psychedelics. | Moderate | Rare | Observational |