LSZ

Lysergic acid 2,4-dimethylazetidide

LA-SS-Az, Lambda, Diazedine

Psychoactive Class

Chemical Class

LSZ is a semi-synthetic psychedelic of the lysergamide class developed in the 2000s by a team led by David E. Nichols at Purdue University¹ as a rigid analog of LSD, with its diethylamide group constrained into an azetidine ring.¹ Like LSD, it is extremely potent and active in the microgram range.² It appeared on research chemical markets around 2012 and is commonly described as producing LSD-like effects with a somewhat more introspective character.

Dosage & Duration

Dosage

Threshold~10 µg

Light10-100 µg

Moderate100-300 µg

Strong300-400 µg

Heavy400+ µg

Dosage guidelines for LSZ remain provisional owing to the compound's limited history of human use. LSZ did not see broad availability until 2013, and the resulting documentation is sparse. Individual responses can differ considerably; some user accounts indicate that LSZ may be modestly more potent than LSD on a weight-for-weight basis, although this has not been conclusively verified.

Duration

Onset20-60 minutes

Come Up15-30 minutes

Peak3-5 hours

Offset2-3 hours

After Effects2-5 hours

Total6-10 hours

Subjective Effects

Effects vary widely by individual, dose, and context.

Forked from Subjective Effect Documentation work

by Josie KinsAugust 2016.

Reagent Testing

Expected colorimetric results for common reagent tests. Colors show reaction change over 1–2 minutes.

Ehrlich(EH)

Hofmann(HM)

Zimm(ZI)

Marquis(MQ)

No reaction

PROtestkit.eu

Pharmacology

Pharmacodynamics

LSZ acts as a non-selective serotonin receptor agonist with especially high affinity for the 5-HT2A, 5-HT2C, and 5-HT1A receptors¹³. It is a potent agonist of the 5-HT2A¹⁴ and 5-HT2C receptors with potency and efficacy comparable to LSD, though it has also been characterized as a 5-HT2A partial agonist. LSZ may be more potent than LSD at the 5-HT1A receptor, and it fully substitutes for LSD in rodent drug discrimination assays at approximately 1.8-fold greater potency⁴². The compound also interacts with dopamine receptors³ and has demonstrated anti-inflammatory effects in preclinical research.

Pharmacokinetics

In pooled human-liver S9 incubations, LSZ produced nine tentatively identified metabolites: lysergic acid amide, lysergic acid, hydroxy lysergic acid amide, N6-demethyl-LSZ, three hydroxy-LSZ isomers, dihydroxy-LSZ, and a hydroxy-LSZ glucuronide. Recombinant-enzyme experiments implicated CYP3A4 in N6-demethylation and both CYP1A2 and CYP3A4 in hydroxylation. Lysergic acid and lysergic acid amide were detected in pooled human liver microsomes but not in the recombinant monooxygenase incubations, so the authors proposed that amidases may mediate those hydrolytic products. These findings describe parallel in-vitro pathways; they do not establish their quantitative importance, sequence, clearance contribution, or clinical interaction effects in living humans, and the positions of several hydroxy metabolites were not definitively assigned.⁵

Interactions

Dangerous

Highest risk

These combinations are considered extremely harmful and should always be avoided. Reactions to these drugs taken in combination are highly unpredictable and have a potential to cause death.

Lithium

Unsafe

Avoid

There is considerable risk of physical harm when taking these combinations, they should be avoided where possible.

Tramadol

Caution

Use caution

These combinations are not usually physically harmful, but may produce undesirable effects, such as physical discomfort or overstimulation. Extreme use may cause physical health issues. Synergistic effects may be unpredictable. Care should be taken when choosing to use this combination.

AmphetaminesCannabisCocaineDiphenhydramineMephedronePregabalin

TripSit

Tolerance

Full Tolerance

Tolerance to the effects of LSZ develops almost immediately after ingestion.

Baseline Reset

Approximately 7 days

Half Tolerance

Approximately 3 days

Cross Tolerance

Serotonergic psychedelics

Harm Potential

Addiction & Dependence

Psychological

Extremely Low

LSZ is not considered habit-forming and the desire to use it may actually decrease with repeated use. It is typically self-regulating in nature.⁶

Physical

Extremely Low

LSZ is not considered physiologically addictive. No physical dependence or withdrawal symptoms have been documented.⁶⁷

Psychosis Risk

Adverse psychological reactions including severe anxiety, paranoia, and psychosis are possible, particularly in individuals predisposed to mental illness. As a psychological amplifier, LSZ can intensify existing mental states and may produce paranoia or distressing experiences such as feelings of dying.

History & Culture

Development as a Research Tool

The development of LSZ traces back to efforts by David E. Nichols and colleagues at Purdue University to create conformationally restricted analogues of LSD for use as pharmacological research tools.¹ The goal was to better understand how LSD orients itself when binding…

Legality

International

LSZ does not appear in the official schedules checked for the 1961 Single Convention or the 1971 Convention on Psychotropic Substances. The 1988 Convention control tables were also checked; LSZ is not listed.

By Country

United StatesUnscheduled (Federal Analogue Act applies)Citation needed

LSZ is not specifically scheduled at the federal level. However, as a structural analogue of LSD, it may be prosecuted under the Federal Analogue Act when sold for human consumption or possessed with intent to ingest. No cases for simple possession alone have been reported.

AustriaIllegal (analog/blanket ban)Anlage II

Neue-Psychoaktive-Substanzen-Verordnung (NPSV), Anlage II; Neue-Psychoaktive-Substanzen-Gesetz (NPSG) § 4¹³¹⁴

LSZ (lysergic acid 2,4-dimethylazetidide) is covered as a 9,10-didehydroergoline-8-carboxamide derivative with substitution at the amide nitrogen under Annex II of Austria’s Neue-Psychoaktive-Substanzen-Verordnung, in force in this form since 19 April 2024. Austria’s Neue-Psychoaktive-Substanzen-Gesetz makes producing, importing, exporting, supplying, or procuring a covered new psychoactive substance for psychoactive human use for gain punishable by up to two years’ imprisonment; aggravated outcomes carry one to ten years.

CanadaNot scheduledUnscheduled

Controlled Drugs and Substances Act¹⁶

LSZ is not controlled under the Controlled Drugs and Substances Act. Health Canada's Drug Analysis Service identifies LSZ as 2,4-dimethylazetidide LSD and records its controlled status as not controlled.

FranceIllegalStupéfiant

Arrêté du 22 février 1990 fixant la liste des substances classées comme stupéfiants¹⁹

LSZ is classified as a narcotic substance in France. It appears by name in the national list of substances classified as stupéfiants.

IsraelNot scheduledחלק א׳ סימן ב׳

Dangerous Drugs Ordinance [New Version], 5733-1973²⁴²⁵

LSZ (lysergic acid 2,4-dimethylazetidide) is not listed in the First Addendum to Israel's Dangerous Drugs Ordinance [New Version], 5733-1973. The Ordinance treats only a substance listed in that Addendum, including its salt and a preparation, compound, mixture, or solution, as a dangerous drug; the Addendum's LSD entry and its separate provision for listed substances' optical isomers, stereoisomers, esters, and ethers do not name LSZ. Israel therefore does not schedule LSZ under this Ordinance.

LatviaIllegalI saraksts

Law On the Procedures for the Coming into Force and Application of the Criminal Law²⁸²⁹³⁰

Since 1 June 2021, LSZ (lysergic acid 2,4-dimethylazetidide) is included in Latvia's Schedule I through the generic lysergamides entry, which expressly covers lysergic-acid amides with the amide nitrogen incorporated in a ring. Schedule I substances may not be cultivated, manufactured, prepared, imported, exported, distributed, advertised, transported, stored, transferred, purchased, used, or sent through Latvia.

PolandIllegal (analog/blanket ban)VI-NPS

Rozporządzenie Ministra Zdrowia z dnia 17 sierpnia 2018 r. w sprawie wykazu substancji psychotropowych, środków odurzających oraz nowych substancji psychoaktywnych (tekst jednolity: Dz.U. 2024 poz. 1139)³³³⁴³⁵

LSZ (lysergic acid 2,4-dimethylazetidide) is covered in Poland as a new psychoactive substance by the generic VI-NPS class for tryptamine derivatives. The class covers Δ9,10-ergolene derivatives whose amide nitrogen forms a dimethylazetidine ring, so LSZ is controlled even though it is not separately named; the regulation has applied since 21 August 2018. Unauthorized possession, manufacture, and supply of a new psychoactive substance are regulated under the Act on Counteracting Drug Addiction.

SingaporeIllegalFirst Schedule

Misuse of Drugs Act 1973³⁸³⁹

LSZ is a controlled drug in Singapore. The First Schedule to the Misuse of Drugs Act identifies it as lysergic acid 2,4-dimethylazetidide.

SwedenIllegalFörteckning I

HSLF-FS 2015:35⁴²⁴³

Classified as a narcotic substance as of January 26, 2016, following its emergence on the designer drug market.⁴⁴ Manufacturing, trade, and possession are prohibited.

TurkeyIllegal

Classified as a controlled drug under national drug legislation. Possession, production, supply, and importation are prohibited.

ArgentinaIllegalAnexo I

Decreto 560/2019¹¹¹²

LSZ is classified as an estupefaciente in Argentina. Decreto 560/2019 includes LSZ, identified as 2,4-dimethylazetidide of lysergic acid, in Annex I.

BelgiumIllegalAnnex IV

Royal Decree of 6 September 2017 regulating narcotic drugs and psychotropic substances¹⁵

LSZ is included in Belgium's official agency publication of Annex IV to the controlled-substances regime. The publication identifies it as lysergic acid 2,4-dimethylazetidide.

DenmarkIllegalListe B

Bekendtgørelse nr. 965 af 25. august 2015 om ændring af bekendtgørelse om euforiserende stoffer¹⁷¹⁸

Specifically named on the list of controlled substances as of August 25, 2015. Possession, distribution, and manufacture are prohibited.

GermanyIllegal (analog/blanket ban)Lysergamide

Verordnung zur Änderung der Anlage des Neue-psychoaktive-Stoffe-Gesetzes und von Anlagen des BtMG^20212223

Controlled under the New Psychoactive Substances Act as of July 18, 2019.²¹ Production, import with intent to market, administration to others, and trading are punishable offenses. Possession is prohibited but not subject to criminal penalty.

JapanIllegalDesignated drug

Ordinance Partially Amending the Ordinance Designating Designated Drugs and Specifying the Use of Designated Drugs²⁶²⁷

Regulated under the Pharmaceutical Affairs Law (Pharmaceutical and Medical Device Act). Possession and sale are illegal without proper authorization.

NorwayNot scheduledNarkotikalisten

Forskrift om narkotika (narkotikaforskriften)³¹³²

LSZ (lysergic acid 2,4-dimethylazetidide; LA-SS-Az) is not named in Norway's current Narkotikalisten. The Narkotikaforskriften defines narcotics as substances, substance groups, drugs, plants and fungi listed there, and extends that status to salts, stereoisomers, esters, ethers and preparations of listed items with actual or assumed psychoactive effect. The list and those enumerated extensions do not identify LSZ or establish a general structural-analogue category that captures it.

PortugalIllegal (analog/blanket ban)Outros

Decreto-Lei n.º 54/2013, de 17 de abril; Portaria n.º 154/2013, de 17 de abril³⁶³⁷

Portugal classifies LSZ as a derivative of LSA (lysergic acid amide), which is listed in the annex to Portaria n.º 154/2013 under “Outros.” Article 3 of Decreto-Lei n.º 54/2013 extends that classification to derivatives, isomers, salts, and preparations of listed substances. Production, import, export, advertising, distribution, sale, possession, and supply of the resulting new psychoactive substance are prohibited unless authorised by INFARMED for industrial or pharmaceutical use; the regime entered into force in April 2013.

South AfricaIllegal (analog/blanket ban)Schedule 2 Part III

Drugs and Drug Trafficking Act 140 of 1992, as amended by the Drugs and Drug Trafficking Amendment Act 14 of 2022⁴⁰⁴¹

LSZ is an analogue-covered undesirable dependence-producing substance under Schedule 2 Part III: the schedule names lysergide (lysergic acid diethylamide) and extends each listed substance to chemically related homologues with a similar structural fragment or similar pharmacodynamic properties. The current Schedule 2 was substituted with effect from 14 December 2022. Use, possession, and dealing are prohibited except under the Act's specified lawful medicinal and regulatory exceptions; contravention of the possession prohibition carries up to 15 years' imprisonment, while dealing carries up to 25 years.

SwitzerlandIllegalVerzeichnis E

Betäubungsmittelverzeichnisverordnung des EDI (BetmVV-EDI), amendment of 2 November 2015⁴⁵⁴⁶

Specifically named and added to Verzeichnis E (Schedule E) of the controlled substances ordinance as of December 1, 2015.⁴⁷

United KingdomIllegalClass A

The Misuse of Drugs Act 1971 (Amendment) (No. 2) Order 2014⁴⁸⁴⁹

Specifically named as a controlled substance under the Misuse of Drugs Act 1971 as of January 7, 2015.⁴⁸ As a Class A substance, it carries the most severe penalties for possession, supply, and production.

References

Source Pages

Citations

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LSZ

Lysergic acid 2,4-dimethylazetidide

LA-SS-Az, Lambda, Diazedine

Psychoactive Class

Psychedelic

Chemical Class

Lysergamide