LSZ
lysergic acid 2,4-dimethylazetidide
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LSZ (lysergic acid 2,4-dimethylazetidide) — Diazedine, Lambda — is a semi-synthetic psychedelic of the lysergamide class. It is a structural analog of LSD, equipotent in animal behavioral tests.[1] It activates serotonin receptors in the brain, producing the visual and cognitive shifts characteristic of classical psychedelics.[1]
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Synthesized in 2002 by David Nichols as a tool for studying how LSD binds to its primary receptor,[2] LSZ was never intended for human use. It appeared on European designer drug markets in late 2013, quickly prompting legal controls in the UK, Germany, Sweden, and Denmark.[1] Today it remains a niche compound with limited circulation, unscheduled internationally but controlled in several countries.
Subjective effects include geometric visual patterns, color enhancement, time alteration, thought acceleration, and ego dissolution. The experience closely resembles LSD — a broad shift across perception and cognition — though possibly shorter and slightly less analytically stimulating. Thought loops, anxiety during the peak, and difficulty sleeping are common unwanted effects.
LSZ does not produce physical dependence, and no lethal dose has been established.[3] The primary danger is psychological — dose-dependent anxiety and ego dissolution can escalate to panic, with highest risk for those predisposed to psychotic disorders.[4] No controlled human study has been conducted; what is known comes from animal tests, laboratory binding data, and structural analogy to LSD.
History[edit]
Discovery
LSZ was synthesized in 2002 by David Nichols as a research tool for studying how LSD binds to its primary receptor.[2] Three diastereomers were prepared; only the (2S,4S) isomer showed potent activity, confirming the specific geometry needed.[2]
Scientific significance
The rigid azetidine ring locked LSD's flexible amide group into a defined shape, letting researchers determine which orientation activates the serotonin receptor. The finding that only one geometry produced LSD-like activity[2] helped clarify how lysergamides interact with the receptor at the molecular level. LSZ attracted no clinical interest and was not studied further by the original research group.
Novel psychoactive substance market
LSZ appeared on European designer drug markets in December 2013, distributed as powder and on blotter.[1] The UK classified it as Class A in January 2015, with Denmark, Switzerland, and Sweden following within a year.[5]
The names "Diazedine" and "Lambda" may trace to an unverified account that clandestine chemists William Leonard Pickard and Gordon Todd Skinner synthesized a compound matching LSZ's description around 2000 — before its formal publication.[5] This claim, originating from journalist Hamilton Morris's interview with Krystle Cole, has no primary source confirmation. In 2023, LSZ was identified in sheet products in Japan alongside other LSD analogs, confirming continued global distribution more than a decade after its first appearance.[6]
Chemistry[edit]
Structure
LSZ belongs to the lysergamide family — the same chemical class as LSD.[2] Where LSD carries a flexible diethylamide side chain, LSZ replaces it with a rigid four-membered nitrogen ring that locks the molecule's shape.[2] Its molecular formula is C₂₁H₂₅N₃O, with a molecular weight of 335.4 g/mol.
| Molecular formula | C₂₁H₂₅N₃O |
| Molecular weight | 335.4 g/mol |
Pharmacology[edit]
Mechanism of action
LSZ produces its psychedelic effects primarily by activating serotonin receptors.[2][1] Blocking those receptors completely eliminates LSZ's behavioral effects in animals,[1] and blocking the same receptors eliminates nearly all acute LSD effects in humans.[7]
Like other lysergamides, LSZ likely also engages dopamine and adrenergic receptors beyond its primary serotonin target.[8][9] Whether LSZ shares LSD's reported late-phase dopaminergic shift[10] is unknown.
Pharmacokinetics
No human pharmacokinetic data exist for LSZ. Based on LSD studies, oral onset takes about 1–2 hours and effects last approximately 7–11 hours depending on dose.[11][12][13][14] LSZ is broken down in the liver, and the parent compound itself does not appear in urine — standard drug tests will not detect it.[15]
Neuroscience[edit]
Where it acts
No brain imaging studies have been done with LSZ. Its neural effects are inferred from LSD research. Activating serotonin receptors disrupts the brain's normal sensory filter, allowing more information to reach consciousness and increasing communication between brain regions that don't ordinarily connect — experienced as the fluid, boundary-dissolving quality of the psychedelic state.
Why it matters
One framework proposes that activating serotonin receptors weakens the brain's reliance on prior expectations, allowing raw sensory experience to override entrenched thought patterns. This accounts for the dissolution of habitual thinking and ego boundaries characteristic of lysergamides.
LSD also activates a receptor involved in structural brain plasticity at far higher affinity than classical antidepressants.[16] Whether LSZ engages this receptor with similar affinity is unknown.
- Does LSZ bind the same plasticity receptor as LSD, or does its structural difference alter this?
- Does LSZ's rigid molecular shape affect how long it stays bound to serotonin receptors — potentially explaining the reported shorter duration?
- Does LSZ share LSD's reported two-phase pattern — an early serotonergic phase followed by a later dopaminergic phase?
Subjective Effects[edit]
LSZ produces a broad, enveloping shift across perception, thought, and emotion. Colors brighten, patterns emerge across surfaces, and the boundary between self and surroundings softens. The experience builds gradually and occupies the entire conscious field. Set and setting strongly shape whether it trends toward introspection or anxious destabilization.
Community reports position LSZ as closely resembling LSD in character — the same broad qualitative shift, possibly shorter and slightly less analytically stimulating. Whether this difference is pharmacological — LSZ may act as a partial agonist at serotonin receptors[5] — or simply a product of inconsistent blotter dosing[1] remains unresolved; no controlled data exist.
Effect Grid
At common doses (150–300 µg oral), the full psychedelic experience is established. Pronounced open-eye visuals emerge: geometric patterns overlaying surfaces, significant color saturation and shifting, drifting and morphing of objects, and tracers behind moving objects. Closed-eye visuals include vivid geometric imagery and internal hallucinations. Time distortion becomes prominent. Thought acceleration and enhanced pattern recognition produce novel associations and conceptual insights. Emotional responses intensify markedly — music, art, and interpersonal connections can feel profoundly meaningful.
Physically, jaw tension, stimulation, temperature dysregulation, and peripheral vasoconstriction (cold extremities) are common. Appetite is suppressed. Difficulty urinating may occur.
This dose range demands a full-day commitment. Functional capacity for routine tasks is substantially impaired. Sleep is unlikely for 8+ hours.
Modeled from the effect's dose-dependence curve — not per-substance measurements.
Tracers · Geometry · Visual breathing · Holotropic state · Depth perception distortion · Perspective distortion · Symmetrical texture repetition · Touch enhancement · Visual morphing · After-images · Brightness alteration · Environmental patterning · Light sensitivity · Sound sensitivity · Visual haze / noise · Visual melting · Auditory distortion · Auditory enhancement · Peripheral vision distortion · Proprioceptive distortion · Spatial disorientation · Visual diffraction · Visual acuity enhancement · Auditory misinterpretation · Peripheral misidentification · Synesthesia · Vestibular distortion · Visual processing acceleration · Visual magnification · Dreaming enhancement · Ganzfeld effect · Olfactory enhancement · Tinnitus · Flashbacks · Object transformations · Internal hallucinations · Object activation · Visual recursion · Environmental orbism / cubism · External hallucinations · Perspective hallucinations · Visual flipping · Auditory hallucinations · Visual scenery slicing · Persisting hallucinations
Depth perception distortion · Perspective distortion · Symmetrical texture repetition · Touch enhancement · Visual morphing · After-images · Brightness alteration · Environmental patterning · Light sensitivity · Sound sensitivity · Visual haze / noise · Visual melting · Auditory distortion · Auditory enhancement · Peripheral vision distortion · Proprioceptive distortion · Spatial disorientation · Visual diffraction · Visual acuity enhancement · Auditory misinterpretation · Peripheral misidentification · Synesthesia · Vestibular distortion · Visual processing acceleration · Visual magnification · Dreaming enhancement · Ganzfeld effect · Olfactory enhancement · Tinnitus · Flashbacks · Object transformations · Internal hallucinations · Object activation · Visual recursion · Environmental orbism / cubism · External hallucinations · Perspective hallucinations · Visual flipping · Auditory hallucinations · Visual scenery slicing · Persisting hallucinations
Stimulation · Wakefulness · Appetite suppression · Body high · Insomnia · Nausea · Heart rate perception changes · Tactile euphoria · Tingling / electric sensations · Vibrations / buzzing · Breathing alteration · Dizziness · Dry mouth · Excessive sweating · Laughter fits · Muscle tension · Physical fatigue · Restlessness · Bodily lightness · Bodily pressures · Body schema distortion · Motor control impairment · Sexual arousal enhancement · Abnormal heartbeat · Bodily heaviness · Headache · Involuntary body movements · Muscle relaxation · Nystagmus (eye wobbles) · Trembling · Yawning · Bruxism · Motor control enhancement · Vomiting · Bodily dissociation · Tactile hallucination
Body high · Insomnia · Nausea · Heart rate perception changes · Tactile euphoria · Tingling / electric sensations · Vibrations / buzzing · Breathing alteration · Dizziness · Dry mouth · Excessive sweating · Laughter fits · Muscle tension · Physical fatigue · Restlessness · Bodily lightness · Bodily pressures · Body schema distortion · Sexual arousal enhancement · Abnormal heartbeat · Bodily heaviness · Headache · Involuntary body movements · Muscle relaxation · Nystagmus (eye wobbles) · Trembling · Yawning · Bruxism · Motor control enhancement · Vomiting · Bodily dissociation · Tactile hallucination
Pattern recognition enhancement · Aesthetic enhancement · Introspection enhancement · Openness enhancement · Thought connectivity · Thought acceleration · Thought loops · Cognitive euphoria · Cognitive flexibility · Increased nature relatedness · Multiple thought streams · Creativity enhancement · Thought disorganization · Memory suppression · Synchronicity · Analysis enhancement · Humor enhancement · Cognitive impairment · Focus suppression · Memory fragmentation · Cognitive fatigue · Confusion · Information processing enhancement · Information processing suppression · Memory replays · Motivation suppression · Focus enhancement · Language enhancement · Motivation enhancement · Cognitive dysphoria · Memory enhancement · Thought organization · Language suppression · Thought deceleration · Delusions · Amnesia · Delirium
Openness enhancement · Thought connectivity · Thought acceleration · Thought loops · Cognitive euphoria · Cognitive flexibility · Increased nature relatedness · Multiple thought streams · Creativity enhancement · Thought disorganization · Memory suppression · Synchronicity · Analysis enhancement · Humor enhancement · Cognitive impairment · Focus suppression · Memory fragmentation · Cognitive fatigue · Confusion · Information processing enhancement · Information processing suppression · Memory replays · Motivation suppression · Focus enhancement · Language enhancement · Motivation enhancement · Cognitive dysphoria · Memory enhancement · Thought organization · Language suppression · Thought deceleration · Amnesia · Delirium
Simultaneous emotions · Empathy enhancement · Anxiety · Catharsis · Anxiety suppression · Dysphoria · Irritability · Mania
Catharsis · Anxiety suppression · Dysphoria · Irritability
Trust enhancement · Depersonalization · Sociability enhancement · Automaticity · Compulsive behavior reduction · Flow state · Communication enhancement · Communication suppression · Ego inflation · Sociability suppression · Social disconnection · Self-control enhancement · Boundary dissolution · Ego dissolution · Identity alteration · Cognitive disconnection · Telepathic feelings
Compulsive behavior reduction · Flow state · Communication enhancement · Communication suppression · Ego inflation · Sociability suppression · Social disconnection · Self-control enhancement · Boundary dissolution · Ego dissolution · Identity alteration · Cognitive disconnection · Telepathic feelings
Time cessation
Transpersonal visions · Transpersonal memory access · Entity contact · Cessation · Death-rebirth sequence · Voidness · Near-death experience
Death-rebirth sequence · Voidness · Near-death experience
Mindfulness enhancement · Lucidity enhancement · Lucid dreaming enhancement · Recursive awareness
Timeline
First alerts emerge 20–45 minutes after ingestion: a subtle shift in body awareness, mild restlessness, and faint perceptual brightening. The onset is gradual and may be ambiguous at lower doses.
Effects build steadily over 30–60 minutes. Visual distortion begins — surfaces may breathe or shimmer. Thought speed increases.
Maximum intensity is sustained for 2–3 hours. Visual effects, cognitive alteration, emotional intensification, and ego dissolution (at higher doses) reach their fullest expression. Time distortion is most pronounced.
Intensity gradually recedes from the peak over 1. 5–2 hours but remains clearly psychedelic. Visuals simplify, emotional tone often stabilizes, and cognitive coherence begins to return.
A gradual return toward baseline over 1. 5–2. 5 hours.
Residual mood elevation, enhanced emotional sensitivity, and subtle perceptual changes may persist for 6–24 hours following the core experience. Sleep quality may be affected on the night of use.
⚠ Do not drive or operate heavy machinery until after a full night of sleep following the experience.
Safety[edit]
- Acute toxicity
- Negligible
- Chronic toxicity
- Low
- Withdrawal
- None
- Tolerance buildup
- rapid
- Tolerance reset
- 7 days
- Physical
- None
- Psychological
- Negligible
- Compulsive redosing
- Negligible
- Dose escalation
- Negligible
- Cross-tol.
- LSD · psilo · mesc
Toxicity
Acute toxicity
No lethal dose has been established for LSZ, and no human fatalities have been reported. The closest class reference is a series of eight massive LSD overdoses in which all patients survived with supportive care alone.[17] Only two deaths in the historical LSD literature have been attributed to direct drug toxicity — most LSD-associated deaths involve behavioral consequences during intoxication.
The low reported fatality count may reflect limited use prevalence and poor forensic detection rather than demonstrated safety.
Cardiovascular effects
LSD — and by class extension LSZ — produces moderate increases in heart rate and blood pressure.[14] LSZ also has estimated activity at a receptor linked to heart valve damage when chronically activated by ergoline compounds.[5][18] At typical psychedelic use frequencies this cardiac risk is theoretical.
Psychological risks
Anxiety, panic, paranoia, and psychosis are recognized risks of classical psychedelics.[3] At doses equivalent to LSD 200 µg, anxiety and ego dissolution intensify significantly,[14][19] and given LSZ's equivalence to LSD in potency, similar dose-dependent escalation is expected. Individuals with personal or family history of psychotic disorders face elevated risk.
Persistent visual disturbances after a psychedelic experience — a condition known as HPPD — is a rare but documented adverse effect.[4] Type 1 involves brief episodic flashbacks; Type 2 involves chronic visual phenomena lasting months to years. No LSZ-specific HPPD cases have been published.
Tolerance and dependence
Tolerance develops rapidly after a single dose — with a half-life of approximately 3 days and full reset within about 7 days.[20][21] Full cross-tolerance exists with LSD, psilocybin, mescaline, and DMT.[20]
Classical psychedelics do not produce physical withdrawal and are not habit-forming.[3][22] Dependence liability is negligible.
Drug interactions
Tramadol inhibits serotonin reuptake and has partial serotonin receptor activity.[23] Combining it with LSZ can cause dangerously elevated serotonin levels, producing high fever, involuntary muscle contractions, and altered consciousness.[24]
Lithium combined with classical psychedelics is associated with seizures in 47% of analyzed reports, with 39% requiring medical attention.[25] Even subtherapeutic lithium levels can trigger seizures within 30 minutes of ingestion.[26]
SSRIs and SNRIs predominantly reduce or eliminate psychedelic effects — chronic SSRI use abolished LSD response in 88% of subjects.[27][28] Serotonin syndrome risk appears low; no signs of serotonin toxicity were found across 10 studies of the combination.[29]
MAOIs block serotonin breakdown and could theoretically amplify effects or contribute to dangerous serotonin overload.[28] No controlled data exist for lysergamide-MAOI combinations.
Cannabis interacts dose-dependently — low doses may reduce anxiety, while high doses significantly intensify ego dissolution and visual effects, increasing the risk of a challenging experience.[30]
Antipsychotics block psychedelic effects through competitive action at serotonin and dopamine receptors.[28]
Contraindications
Psychotic disorders and schizophrenia-spectrum conditions are absolute contraindications. Activating serotonin receptors disrupts sensory filtering and increases dopaminergic activity — mechanisms that may trigger or worsen psychotic episodes.[3] Both personal history and first-degree family history confer risk.
Bipolar disorder is an absolute contraindication. Classical psychedelics may trigger manic or mixed episodes regardless of current mood state.
Concurrent lithium therapy is absolutely contraindicated due to seizure risk. Even subtherapeutic lithium levels may trigger seizures.[25][26]
Concurrent tramadol use is contraindicated due to serotonin syndrome risk.[23]
Severe cardiovascular disease is a relative contraindication. Increases in heart rate and blood pressure[14] make LSZ inadvisable for those with uncontrolled hypertension, recent heart attack, or conditions where acute cardiovascular stress poses danger.
Pregnancy and breastfeeding are absolute contraindications on precautionary grounds. No reproductive toxicology data exist, and ergoline derivatives as a class have uterotonic properties.safety citation needed
Harm Reduction[edit]
Forms & Identification
LSZ circulates as white powder and on blotter paper. Blotter is the most common form. Analytical testing found actual content at 75–87% of labeled doses[1] — a blotter labeled at 150 µg may contain closer to 112–131 µg. Reagent testing confirms a lysergamide is present but cannot verify dose.
LSZ shares a molecular formula with ECPLA (N-ethyl-N-cyclopropyl lysergamide), its constitutional isomer.[31] Standard reagent tests cannot distinguish the two. If source cannot be verified, treat dose cautiously.
Guidelines
- Test all material with an appropriate reagent kit to confirm lysergamide presence.
- Start with a low dose — particularly with a new batch or source, given documented inconsistencies in blotter content.
- Allow at least 2 hours before considering redosing; onset can be gradual.
- Have a sober sitter present, especially at higher doses or for those with limited psychedelic experience.
- Eat lightly beforehand; avoid heavy meals.
- Clear the schedule — block 12–14 hours including onset, peak, and recovery.
- Prepare the space: comfortable seating, controlled lighting, curated music, minimal external obligations.
Set & Setting
LSZ's effects are strongly shaped by psychological state going in (set) and the physical and social environment (setting). A familiar, comfortable space with trusted companions substantially reduces the likelihood of anxiety escalation.
Novelty, crowds, and unfamiliar environments increase the risk of a challenging experience, particularly at higher doses where ego dissolution becomes prominent.
Aftercare & integration. The day following an LSZ experience typically brings fatigue and residual emotional sensitivity. Sleep may remain difficult for several hours after effects subside — this is normal for lysergamides and resolves without intervention.
Integration practices include journaling while the experience is fresh, discussing it with trusted individuals, and allowing several days of reduced obligations. If the experience involved intense anxiety or distressing content, professional support from a psychedelic-informed therapist may help. Persistent visual phenomena or intrusive recollections lasting beyond two weeks warrant clinical evaluation.
Recovery & Support
Classical psychedelics carry negligible abuse liability — compulsive use is rare, and physical withdrawal does not occur. If psychedelic use is becoming a pattern of avoidance or emotional escape, this is worth examining with a therapist rather than a substance-specific recovery program.
For those experiencing lasting psychological difficulty after a psychedelic experience, resources include the Fireside Project (62-FIRESIDE / 623-473-7433), MAPS integration resources, and psychedelic-informed therapists through directories such as the Psychedelic Support Network.
Recovery resources, crisis lines, and support pathways → View all
Emergency Response
Recognizing an emergency: Most difficult psychedelic experiences are distressing but not medically dangerous. Seek immediate help if the person shows signs of self-harm intent, complete dissociation from reality with inability to recognize surroundings, seizures, or sustained high fever.
Immediate steps:
- 1. Stay with the person and speak calmly.
- 2. Move to a quiet, low-stimulation environment if possible.
- 3. Do not physically restrain unless there is immediate danger of self-harm.
- 4. If seizures occur, protect the head and clear the area — do not place anything in the mouth.
- 5. Call emergency services if seizures occur, if the person becomes unresponsive, or if a dangerous combination is suspected (particularly lithium or tramadol).
What to tell the dispatcher: Name the substance (LSZ or "an LSD-like psychedelic"), approximate dose and time of ingestion, current symptoms, and any other substances taken. Good Samaritan laws in many jurisdictions protect those who call for help during a drug-related emergency.
Legal Status[edit]
LSZ is not controlled under international drug treaties.[32] National laws vary widely — several European countries have specifically scheduled LSZ, while others rely on structural analog provisions that may apply when the substance is sold for human consumption.
| Jurisdiction | Classification | Key provisions |
|---|---|---|
| United States | Not specifically scheduled | Federal Analogue Act may apply if marketed for human consumption as an LSD analogue[33] |
| United Kingdom | Class A, Schedule 1 | Specifically named in Misuse of Drugs Act amendment, January 2015[33][5] |
| Germany | NpSG (controlled) | Covered under Neue-psychoaktive-Stoffe-Gesetz; industrial and scientific use only[5] |
| Denmark | Controlled substance | Scheduled May 2015[5] |
| France | Narcotic | Exact scheduling date not confirmed[5] |
| Sweden | Controlled narcotic | Manufacturing, trade, and possession prohibited from January 26, 2016[33][5] |
| Switzerland | Illegal | Controlled from December 2015[5] |
| Canada | Not specifically controlled | Analogue clause risk; not explicitly scheduledcitation needed |
| Australia | Likely prohibited | TGA captures lysergamide analogues broadly; specific LSZ scheduling not confirmedcitation needed |
Analog and blanket provisions
LSZ retains the full ergoline core and differs from LSD only in the amide substituent. In jurisdictions with analog provisions — including the US Federal Analogue Act and the Canadian CDSA analogue clause — LSZ may be prosecuted as an LSD analog when intended for human consumption, even without explicit scheduling. Germany's NpSG controls new psychoactive substances by structural class rather than individual listing.[5]
Legal status changes frequently and varies by jurisdiction. This information is not legal advice. Verify current law in the relevant jurisdiction before drawing any conclusions.
references
- [1] ^abcdefghBrandt SD, Kavanagh PV, Westphal F, Elliott SP, Wallach J, Colestock T, Burrow TE, Chapman SJ, Stratford A, Nichols DE, Halberstadt AL (2017) Return of the lysergamides. Part II: Analytical and behavioural characterization of N6-allyl-6-norlysergic acid diethylamide (AL-LAD) and (2'S,4'S)-lysergic acid 2,4-dimethylazetidide (LSZ) — Drug Testing and Analysis doi:10.1002/dta.1985
- [2]
- [3] ^abcdSchlag AK, Aday J, Salam I, Neill JC, Nutt DJ (2022) Adverse effects of psychedelics: From anecdotes and misinformation to systematic science — Journal of Psychopharmacology doi:10.1177/02698811211069100
- [4] ^abHalpern JH, Lerner AG, Passie T (2018) A Review of Hallucinogen Persisting Perception Disorder (HPPD) and an Exploratory Study of Subjects Claiming Symptoms of HPPD — Current Topics in Behavioral Neurosciences doi:10.1007/7854_2016_457
- [5]
- [6] ^Tanaka R, Kawamura M, Mizutani S, Kikura-Hanajiri R (2023) Identification of LSD analogs, 1cP-AL-LAD, 1cP-MIPLA, 1V-LSD and LSZ in sheet products — Forensic Toxicology doi:10.1007/s11419-023-00661-1