LSZ (lysergic acid 2,4-dimethylazetidide) is a semi-synthetic psychedelic lysergamide and a conformationally restricted analog of LSD designed byDavid E. Nichols andStewart Frescas at Purdue University. The compound replaces LSD's flexible diethylamide group with a rigid2,4-dimethylazetidine ring --- essentially locking the two ethyl groups into a fixed spatial orientation. This elegant structural constraint was not designed to create a recreational drug but to answer a fundamental question in medicinal chemistry: which three-dimensional arrangement of LSD's diethylamide moiety is responsible for its extraordinary potency at the 5-HT2A receptor?
The answer proved striking. Of the three possible stereoisomers around the azetidine ring, the (2'S,4'S)-(+) isomer retained full LSD-like psychedelic activity and wasslightly more potent than LSD itself in rat drug discrimination assays --- while the other isomers showed substantially reduced activity . This demonstrated that LSD's diethylamine groups adopt a specific conformation when bound to the receptor, different from the arrangement observed in X-ray crystal structures of the free molecule.
LSZ appeared on the research chemical market in 2013 in both powdered and blotter form, marketed as a novel lysergamide alongside AL-LAD. Users report effects broadly similar to LSD --- geometric visuals, synesthesia, altered cognition --- with a duration of approximately6--10 hours. Like other Nichols-lab lysergamides, LSZ serves as both a pharmacological tool and a reminder of how small structural changes can illuminate the molecular basis of psychedelic action .
References
Nichols DE, Frescas S, et al. Lysergamides of isomeric 2,4-dimethylazetidines map the binding orientation of the diethylamide moiety in the potent hallucinogenic agent LSD. J Med Chem. 2002;45(19):4344-4349. Brandt SD, et al. Return of the lysergamides. Part II: Analytical and behavioural characterization of AL-LAD and LSZ. Drug Test Anal. 2017;9(1):62-79.
Safety at a Glance
High Risk- Denmark: As of August 25, 2015, LSZ is specifically named on the list of illegal substances in Denmark.
- Japan: LSZ is controlled by the Pharmaceutical Affairs Law in Japan, making it illegal to possess or sell.
- Toxicity: The toxicity and long-term health effects of recreational LSZ do not seem to have been studied in any scientific cont...
- Overdose risk: Fatal overdose from LSZ alone, at doses within the typical recreational range, is extremely unlik...
If someone is in crisis, call 911 or Poison Control: 1-800-222-1222
Dosage
oral
Duration
oral
Total: 6 hrs – 10 hrsHow It Feels
The onset carries a distinctive sharpness. Within twenty to thirty minutes there is a crystalline tightening of perception, as though the resolution of your visual field has been incrementally increased. Colors begin to separate and intensify, and there is a faint geometric shimmer at the edges of patterned surfaces. The body responds with a moderate stimulation, an alert, upright energy that settles into the spine and keeps the posture attentive.
The come-up builds steadily over the next hour. LSZ develops its visual character with increasing confidence: surfaces acquire flowing, organic patterns that are less rigidly geometric than LSD but more structured than tryptamine visuals. There is a quality of depth and dimensionality to these patterns, they seem to exist in layers, floating at varying distances from the surface they inhabit. Colors achieve a rich, saturated intensity, and light sources develop soft halos and prismatic fringes. The body maintains its alert stimulation, with a mild electric warmth and a pleasant sense of physical engagement.
At peak intensity, LSZ occupies a distinctive middle ground in the lysergamide landscape. The visuals are beautiful and active but not overwhelming, a continuous display of flowing patterns, color enhancement, and gentle morphing that rewards sustained attention. The headspace carries moderate depth. There is introspective material here, a willingness to examine emotions and assumptions, but it does not reach the shattering profundity that high-dose LSD can produce. Thoughts are clear enough for conversation but colored by a contemplative, slightly philosophical tone. Music is notably enhanced, with increased spatial separation of instruments and a heightened emotional response to melody and harmony.
The decline is smooth and unhurried, tapering over several hours without abrupt shifts in intensity. The visual overlay simplifies gradually, and the cognitive enhancement settles into a warm, mildly stimulated afterglow. The body remains comfortable throughout the offset, and sleep becomes accessible at a reasonable hour. LSZ leaves behind a sense of having had a complete and satisfying psychedelic experience without the demanding intensity or exhausting duration that characterizes some of its more potent relatives.
Subjective Effects
The effects listed below are based on the Subjective Effect Index (SEI), an open research literature based on anecdotal reports and personal analyses. They should be viewed with a healthy degree of skepticism. These effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects.
Physical Effects
Physical(5)
- Bodily control enhancement— Bodily control enhancement is the subjective feeling of improved physical precision, coordination, a...
- Nausea— An uncomfortable sensation of queasiness and stomach discomfort that may or may not lead to vomiting...
- Pupil dilation— A visible enlargement of the pupil diameter (mydriasis) that can range from subtle widening to drama...
- Seizure— Uncontrolled brain electrical activity causing convulsions and loss of consciousness -- a life-threa...
- Stimulation— A state of heightened physical and mental energy characterized by increased wakefulness, elevated mo...
Tactile(1)
- Tactile enhancement— The sense of touch becomes dramatically heightened, making physical contact feel intensely pleasurab...
Cognitive & Perceptual Effects
Visual(14)
- Colour enhancement— An intensification of the brightness, vividness, and saturation of colors in the external environmen...
- Colour shifting— The visual experience of colors on objects and surfaces cycling through continuous, fluid transforma...
- Depth perception distortions— Alterations in how the distance of objects within the visual field is perceived, causing layers of s...
- Drifting— The visual experience of perceiving stationary objects, textures, and surfaces as appearing to flow,...
- Geometry— The experience of perceiving complex, ever-shifting geometric patterns superimposed over the visual ...
- Internal hallucination— Vivid, detailed visual experiences perceived within an imagined mental landscape that can only be se...
- Pattern recognition enhancement— An increased ability and tendency to perceive meaningful patterns, faces, and images within ambiguou...
- Perspective distortions— Distortion of perceived depth, distance, and size of real objects, making things appear closer, furt...
- Perspective hallucination— A hallucinatory phenomenon in which the observer's visual perspective shifts from the normal first-p...
- Settings, sceneries, and landscapes— The perceived environment in which hallucinatory experiences take place, ranging from recognizable l...
- Symmetrical texture repetition— Textures appear to mirror and tessellate across surfaces in intricate, self-similar symmetrical patt...
- Tracers— Moving objects leave visible trails of varying length and opacity behind them, similar to long-expos...
- Transformations— Objects and scenery undergo perceived visual metamorphosis, smoothly shapeshifting into other recogn...
- Visual acuity enhancement— Vision becomes sharper and more defined than normal, as though a slightly blurry lens has been broug...
Cognitive(20)
- Analysis enhancement— A perceived improvement in one's ability to logically deconstruct concepts, recognize patterns, and ...
- Anxiety— Intense feelings of apprehension, worry, and dread that can range from a subtle background unease to...
- Conceptual thinking— A shift in the nature of thought from verbal, linear sentence structures to intuitive, non-linguisti...
- Creativity enhancement— An increase in the ability to imagine new ideas, overcome creative blocks, think about existing conc...
- Delusion— A delusion is a fixed, false belief that is held with unshakeable certainty and is impervious to con...
- Immersion enhancement— A heightened capacity to become fully absorbed and engrossed in external media such as music, films,...
- Introspection— An enhanced state of self-reflective awareness in which one feels drawn to examine their own thought...
- Mania— Abnormally elevated mood, energy, and activity with impulsive behavior and grandiosity, associated w...
- Memory suppression— A dose-dependent inhibition of one's ability to access and utilize short-term and long-term memory, ...
- Mindfulness— Mindfulness in the substance context refers to a state of heightened present-moment awareness in whi...
- Novelty enhancement— A feeling of increased fascination, awe, and childlike wonder attributed to everyday concepts, objec...
- Panic attack— A panic attack is a discrete episode of acute, overwhelming fear or terror that arises suddenly and ...
- Paranoia— Irrational suspicion and belief that others are watching, plotting against, or intending harm toward...
- Personal bias suppression— A decrease in the personal, cultural, and cognitive biases through which one normally filters their ...
- Psychosis— Psychosis is a serious psychiatric state involving a fundamental break from consensus reality — char...
- Thought acceleration— The experience of thoughts occurring at a dramatically increased rate, as if the mind has been shift...
- Thought disorganization— Thought disorganization is a cognitive impairment in which the normal capacity for structured, seque...
- Thought loops— Becoming trapped in a repeating cycle of thoughts, actions, and emotions that loops every few second...
- Time distortion— Subjective perception of time becomes dramatically altered — minutes may feel like hours, or hours p...
- Wakefulness— An increased ability to stay awake and alert without the desire to sleep. Distinct from stimulation ...
Multi-sensory(1)
- Scenarios and plots— Scenarios and plots are the narrative structures that emerge within hallucinatory states — coherent ...
Transpersonal(3)
- Ego death— A profound dissolution of the sense of self in which personal identity, memories, and the boundary b...
- Spirituality enhancement— A profound intensification of spiritual feelings, mystical awareness, and a sense of sacred connecti...
- Unity and interconnectedness— A profound sense that identity extends beyond the self to encompass other people, nature, or all of ...
Pharmacology
Mechanism of Action
LSZ exerts its psychedelic effects through potent agonism at the serotonin 5-HT2A receptor, the same molecular target responsible for the hallucinogenic properties of LSD and other classical psychedelics. The compound's pharmacological significance lies not just in its activity but in what it reveals about thethree-dimensional requirements for potent 5-HT2A activation by lysergamides.
Binding Affinity and Potency
In drug discrimination studies --- the gold-standard preclinical model for assessing hallucinogenic potential --- rats trained to discriminate LSD from saline fully generalized to LSZ, confirming shared pharmacological activity. The (2'S,4'S)-(+) isomer was the most active, beingslightly more potent than LSD itself, while the (2'R,4'R)-(-) isomer and the cis-isomer showed progressively reduced activity .
In the head-twitch response (HTR) assay in C57BL/6J mice --- another validated model for 5-HT2A-mediated hallucinogenic activity --- LSZ produced robust dose-dependent responses with anED50 of 114.2 nmol/kg, compared to 132.8 nmol/kg for LSD, confirming near-equipotency . This makes LSZ one of the most potent synthetic psychedelics characterized in behavioral assays.
Conformational Insight
The dimethylazetidine ring constrains the two N-alkyl groups into a specific spatial arrangement. The finding that only the (S,S)-isomer retains full LSD-like potency demonstrates that the diethylamide groups of LSD adopt a defined binding conformation at the 5-HT2A receptor that differs from the solid-state conformation observed in X-ray crystallography. This insight was foundational for understanding themolecular pharmacophore of lysergamide psychedelics .
Receptor Selectivity
Like LSD, LSZ likely interacts with multiple serotonin receptor subtypes (5-HT2A, 5-HT2B, 5-HT2C, 5-HT1A) as well as dopamine D2 receptors, though comprehensive selectivity profiling specific to LSZ has not been published beyond the behavioral pharmacology data. The compound's activity profile is broadly consistent with that of a classical serotonergic psychedelic.
References
Nichols DE, Frescas S, et al. Lysergamides of isomeric 2,4-dimethylazetidines map the binding orientation of the diethylamide moiety in LSD. J Med Chem. 2002;45(19):4344-4349. Brandt SD, et al. Return of the lysergamides. Part II: Analytical and behavioural characterization of AL-LAD and LSZ. Drug Test Anal. 2017;9(1):62-79.
Detection Methods
Urine Detection
LSZ and its metabolites are not targeted by standard immunoassay-based urine drug screens. Because lysergamides are active at microgram doses, the absolute quantity of drug and metabolite present in biological samples is extremely low, making detection inherently difficult. Specialized urine assays using liquid chromatography-tandem mass spectrometry (LC-MS/MS) can identify lysergamide metabolites within approximately 24 to 72 hours after ingestion, though this window is shorter than most other drug classes due to rapid metabolism and renal clearance.
Blood and Serum Detection
Blood detection windows for LSZ are narrow. Plasma concentrations peak within 1 to 3 hours of oral administration and fall below detectable thresholds within 6 to 12 hours for most analytical methods. LC-MS/MS can extend this window modestly, but serum testing for lysergamides is rarely performed outside of forensic or research contexts due to the specialized equipment required and the very low concentrations involved.
Standard Drug Panel Inclusion
LSZ is NOT included on standard 5-panel, 10-panel, or 12-panel drug screens. These panels test for amphetamines, cannabinoids, cocaine metabolites, opiates, and PCP (with extended panels adding benzodiazepines, barbiturates, and similar classes). Lysergamides do not cross-react with any of these immunoassay targets. Detection requires a specific request for lysergamide testing, which is uncommon in workplace, probationary, or emergency department screening.
Confirmatory Methods
When lysergamide use is specifically suspected, confirmatory testing relies on LC-MS/MS or gas chromatography-mass spectrometry (GC-MS). LC-MS/MS is the preferred method due to its superior sensitivity at picogram-per-milliliter concentrations. Immunoassay-based LSD-specific screens exist but suffer from high false-negative rates with novel lysergamide analogs, as antibody cross-reactivity varies between compounds.
Reagent Testing (Harm Reduction)
For harm reduction identification, the Ehrlich reagent is the primary tool for LSZ. A small sample placed on the reagent should produce a purple to violet color change, indicating the presence of an indole moiety characteristic of lysergamides. The Hofmann reagent provides a confirmatory blue to purple reaction. Importantly, the Marquis reagent shows no reaction or a faint olive discoloration with lysergamides, which helps distinguish them from other compound classes. A positive Ehrlich result does not confirm the specific lysergamide identity but does rule out NBOMe and NBOH compounds, which show no Ehrlich reaction. Using both Ehrlich and Hofmann reagents together provides greater confidence in lysergamide identification.
Interactions
| Substance | Status | Note |
|---|---|---|
| 3-FMA | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| 4-MMC | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| 8-Chlorotheophylline | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| Adrafinil | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| Anandamide | Caution | Cannabis can unpredictably intensify psychedelic effects and increase anxiety |
| Cannabis | Uncertain | — |
| 1,3-Butanediol | Low Risk & Synergy | Cross-tolerance exists; effects compound |
| 25E-NBOH | Low Risk & Synergy | Cross-tolerance exists; effects compound |
| 2C-T | Low Risk & Synergy | Cross-tolerance exists; effects compound |
| 2C-T-2 | Low Risk & Synergy | Cross-tolerance exists; effects compound |
History
Origin and Synthesis
LSZ was synthesized as part of a structure-activity relationship (SAR) investigation byDavid E. Nichols and Stewart Frescas at Purdue University, published in the Journal of Medicinal Chemistry in September 2002 . The study addressed a deceptively simple question that had remained unanswered for decades: when LSD binds to the 5-HT2A receptor, what spatial orientation do its diethylamide groups actually adopt?
To answer this, Nichols and Frescas prepared lysergamides using all three stereoisomers of 2,4-dimethylazetidine --- a four-membered nitrogen-containing ring that acts as arigid analog of diethylamine. By locking the two methyl groups (standing in for ethyl groups) into fixed positions, each isomer presented a different spatial arrangement to the receptor. The dramatic difference in activity between isomers --- with only the (S,S)-(+) form matching LSD's potency --- provided the first direct evidence for the bound conformation of LSD's amide substituent.
Research Chemical Emergence
LSZ remained a purely academic compound for over a decade until it appeared on the research chemical (NPS) market in 2013, offered in both powdered and blotter form alongside other Nichols-lab lysergamides like AL-LAD. Brandt et al. (2017) subsequently provided the first comprehensive analytical and behavioral characterization of commercial LSZ samples, confirming the identity and purity of market material and documenting its LSD-like behavioral pharmacology in mice .
References
Nichols DE, Frescas S, et al. Lysergamides of isomeric 2,4-dimethylazetidines map the binding orientation of the diethylamide moiety in LSD. J Med Chem. 2002;45(19):4344-4349. Brandt SD, et al. Return of the lysergamides. Part II: Analytical and behavioural characterization of AL-LAD and LSZ. Drug Test Anal. 2017;9(1):62-79.
Harm Reduction
-not habit-forming and the desire to use it can actually decrease with use. It is most often self-regulating.almost immediately after ingestion. After that,37 days to be back at baseline (in the absence of further consumption). LSZ presents cross-tolerance with all psychedelics, meaning that all psychedelics will have a reduced effect after the consumption of LSZ.
Denmark: As of August 25, 2015, LSZ is specifically named on the list of illegal substances in Denmark.
Germany: LSZ is controlled under the NpSG (New Psychoactive Substances Act) as of July 18, 2019. Production and import with the aim to place it on the market, administration to another person and trading is punishable. Possession is illegal but not penalized.
Japan: LSZ is controlled by the Pharmaceutical Affairs Law in Japan, making it illegal to possess or sell.
Latvia: LSZ is illegal in Latvia. Although it isn't officially scheduled, it is controlled as an LSD structural analog due to an amendment made on June 1, 2015.
Sweden: Following its sale as a designer drug, LSZ was made illegal in Sweden on January 26, 2016.
Switzerland: LSZ is a controlled substance specifically named under Verzeichnis E. It was added to the list of controlled substances on the December 1, 2015.
Turkey:** LSZ is a classed as drug and is illegal to possess, produce, supply, or import.
United Kingdom: As of January 7, 2015, LSZ is specifically named in the U.K. Misuse of Drugs Act as a Class A drug.
Responsible use
Research chemical
Lysergamide
Psychedelic
LSD
LSZ (Wikipedia)
Toxicity & Safety
The toxicity and long-term health effects of recreational LSZ do not seem to have been studied in any scientific context and the exact toxic dose is unknown. This is because LSZ is a research chemical with very little history of human usage. Anecdotal evidence from people within the psychonaut community who have tried LSZ suggests that there are no negative health effects attributed to simply trying the drug by itself at low to moderate doses and using it very sparingly (but nothing can be completely guaranteed). Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.
It is strongly recommended that one use harm reduction practices when using this substance.
Tolerance and addiction potential
LSZ is not habit-forming and the desire to use it can actually decrease with use. It is most often self-regulating.
Tolerance to the effects of LSZ is built almost immediately after ingestion. After that, it takes about 3 days for the tolerance to be reduced to half and 7 days to be back at baseline (in the absence of further consumption). LSZ presents cross-tolerance with all psychedelics, meaning that all psychedelics will have a reduced effect after the consumption of LSZ.
Dangerous interactions
Warning: Many psychoactive substances that are reasonably safe to use on their own can suddenly become dangerous and even life-threatening when combined with certain other substances. The following list provides some known dangerous interactions (although it is not guaranteed to include all of them).
Always conduct independent research (e.g. Google, DuckDuckGo, PubMed) to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.
Lithium - Lithium is commonly prescribed for the treatment of bipolar disorder. There is a large body of anecdotal evidence that suggests taking it with psychedelics significantly increases the risk of psychosis and seizures. As a result, this combination is strictly discouraged.
Cannabis - Cannabis may have an unexpectedly strong and unpredictable synergy with the effects of LSZ. Caution is advised with this combination as it can significantly increase the risk of adverse psychological reactions like anxiety, paranoia, panic attacks, and psychosis. Users are advised to start off with only a fraction of their normal cannabis dose and take long breaks between hits to avoid unintentional overdose.
Stimulants - Stimulants like amphetamine, cocaine or methylphenidate affect many parts of the brain and alter dopaminergic function. This combination can increase the risk of anxiety, paranoia, panic attacks, and thought loops. This interaction may also result in an elevated risk of mania and psychosis.
Tramadol - Tramadol is well-documented to lower the seizure threshold and psychedelics may act to trigger seizures in susceptible individuals.
Addiction Potential
not habit-forming
Overdose Information
Fatal overdose from LSZ alone, at doses within the typical recreational range, is extremely unlikely based on the available evidence for classical psychedelics. The therapeutic index for most psychedelics is very wide.
However, psychological emergencies can occur and require appropriate response:
- Severe anxiety, panic, or psychotic episodes
- Dangerous behavior due to impaired reality testing
- Self-harm in the context of a distressing experience
Emergency management: If someone is experiencing a severe adverse reaction, move them to a calm, quiet environment. Speak reassuringly. Do not restrain unless there is immediate danger. Benzodiazepines (if available and the person is conscious and able to swallow) can reduce acute anxiety. If psychotic symptoms, self-harm risk, or medical distress is present, seek emergency medical attention.
Medical attention: Seek help immediately for seizures, extremely elevated body temperature, signs of serotonin syndrome (agitation, tremor, diarrhea, rapid heart rate), or if the substance consumed is uncertain.
Tolerance
| Full | almost immediately after ingestion |
| Half | 3 days |
| Zero | 7 days |
Cross-tolerances
Legal Status
Denmark: As of August 25, 2015, LSZ is specifically named on the list of illegal substances in Denmark.
Germany: LSZ is controlled under the NpSG (New Psychoactive Substances Act) as of July 18, 2019. Production and import with the aim to place it on the market, administration to another person and trading is punishable. Possession is illegal but not penalized.
Japan: LSZ is controlled by the Pharmaceutical Affairs Law in Japan, making it illegal to possess or sell.
Latvia: LSZ is illegal in Latvia. Although it isn't officially scheduled, it is controlled as an LSD structural analog due to an amendment made on June 1, 2015.
Sweden: Following its sale as a designer drug, LSZ was made illegal in Sweden on January 26, 2016.
Switzerland: LSZ is a controlled substance specifically named under Verzeichnis E. It was added to the list of controlled substances on the December 1, 2015.
Turkey:** LSZ is a classed as drug and is illegal to possess, produce, supply, or import.
United Kingdom: As of January 7, 2015, LSZ is specifically named in the U.K. Misuse of Drugs Act as a Class A drug.
Responsible use
Research chemical
Lysergamide
Psychedelic
LSD
LSZ (Wikipedia)
LSZ (Erowid Vault)
LSZ (Isomer Design)
Discussion
The Big & Dandy LSZ Thread (Bluelight)
Experience Reports (2)
Tips (5)
If you experience anxiety or thought loops on LSZ, change your physical environment: move to a different room, go outside, change the music, or hold something cold. A change of scenery can instantly shift a difficult headspace.
Start with a low dose of LSZ if it is your first time. You can always take more next time but you cannot take less once ingested. The difference between a comfortable and an overwhelming experience can be surprisingly small.
Do not combine LSZ with lithium (seizure risk), tramadol (seizure/serotonin syndrome risk), or cannabis at higher doses unless very experienced. Cannabis dramatically intensifies and can destabilize a psychedelic experience.
Clear your schedule for the full duration of LSZ plus afterglow. Do not plan any obligations, driving, or important decisions for the day. Having a time pressure or commitment hanging over you adds unnecessary anxiety.
Use a milligram scale to weigh LSZ if it comes as a powder. Eyeballing doses of potent psychedelics is irresponsible. A quality 0.001g scale costs under $30 and could prevent a seriously overwhelming experience.
See Also
References (5)
- Psilocybin produces substantial and sustained decreases in depression and anxiety — Griffiths et al. Journal of Psychopharmacology (2016)paper
- Neural correlates of the LSD experience revealed by multimodal neuroimaging — Carhart-Harris et al. PNAS (2016)paper
- PubChem: LSZ
PubChem compound page for LSZ (CID: 71301249)
pubchem - LSZ - TripSit Factsheet
TripSit factsheet for LSZ
tripsit - LSZ - Wikipedia
Wikipedia article on LSZ
wikipedia