AL-LAD

Discovery

AL-LAD was first synthesized in 1976 by Tetsukichi Niwaguchi, Yuji Nakahara, and Hisashi Ishii at the National Institute of Hygienic Sciences in Tokyo, as part of a systematic investigation into norlysergic acid amide derivatives.^[2] The first pharmacological characterization came in 1985, when Andrew Hoffman and David Nichols demonstrated that AL-LAD possessed LSD-like discriminative stimulus properties in rats, establishing it alongside ETH-LAD and PRO-LAD as active LSD analogs.^[3]

Research chemical era

AL-LAD remained an academic curiosity for nearly three decades. It entered the commercial new psychoactive substances market in 2013, distributed as a tartrate salt on blotter paper.^[4] Its emergence coincided with a wave of novel lysergamides — including 1P-LSD, ETH-LAD, and LSZ — marketed as legal alternatives to LSD in jurisdictions where the parent compound was controlled.^[8]

Present status

No clinical or institutional research program has been established for AL-LAD. Unlike LSD or psilocybin, which have progressed through clinical trials for psychiatric indications, AL-LAD remains a compound of preclinical and forensic-analytical interest. As of 2023, it continues to appear in the NPS supply chain — Kavanagh et al. detected AL-LAD as an impurity in 1cP-AL-LAD blotter samples.^[9]

Structural class

AL-LAD belongs to the lysergamide family of ergoline alkaloids. Its core structure is 6-norlysergic acid diethylamide — the N6-demethylated form of LSD — with an allyl (prop-2-en-1-yl) group attached at the N6 nitrogen. This single substitution distinguishes AL-LAD from LSD (N6-methyl), ETH-LAD (N6-ethyl), and PRO-LAD (N6-propyl), all characterized as a systematic series by Hoffman and Nichols.^[3]

AL-LAD is also the active metabolite of the prodrug 1P-AL-LAD, which undergoes liver-mediated removal of its 1-propanoyl group to yield AL-LAD as the primary active product.^[11]

Molecular properties

The molecule comprises a tetracyclic ergoline ring system fused with an indole moiety, bearing a diethylamide group at C-9 and the N6-allyl substituent. The allyl group introduces a terminal alkene capable of metabolic oxidation.^[12]

Stereochemistry

AL-LAD has two chirality centres at C-6a and C-9, with absolute configuration (6aR,9R) — the natural d-lysergic acid configuration shared by all pharmacologically active ergolines, including LSD. It is synthesized and distributed as a single enantiomer.

Physical properties

No published data on melting point, solubility, or thermostability have been identified. As an ergoline compound, AL-LAD is expected to be light-sensitive and subject to degradation upon prolonged UV exposure. The commercial form is a tartrate salt distributed on blotter paper.^[4] citation needed

Mechanism of action

AL-LAD activates the serotonin 5-HT₂A receptor, the primary target responsible for psychedelic effects. This was confirmed in the mouse head-twitch response assay — a standard behavioral test for hallucinogenic activity — where pretreatment with the selective 5-HT₂A blocker M100907 abolished the response across the lysergamide series.^[1]

Brandt et al. measured AL-LAD's potency in the same assay, finding an ED₅₀ of 174.9 nmol/kg compared to 132.8 nmol/kg for LSD — placing AL-LAD at roughly 75% of LSD's potency.^[4] The dose-response curve follows an inverted U shape, with peak response at 200 µg/kg.

The downstream signaling pathway involves 5-HT₂A coupling to Gq/11 proteins rather than β-arrestin2 recruitment, as demonstrated by Wallach et al.^[13] This Gq-dependent pathway is presumed to mediate AL-LAD's psychedelic activity, though direct confirmation for this specific compound has not been published.

No binding affinity data have been published for AL-LAD at any receptor target.

Secondary targets

As an ergoline derivative, AL-LAD likely interacts with multiple receptor systems beyond 5-HT₂A. LSD and structural analogs bind dopamine D₂ receptors with affinity comparable to their serotonin binding,^[14] and partial agonism at 5-HT₁A receptors is characteristic of the ergoline class. The related lysergamide LSM-775 showed 5-HT₁A activity strong enough to mask its psychedelic effects in behavioral assays,^[15] illustrating how this secondary target can shape the overall experience.

LSD is also a potent 5-HT₂B agonist, a property linked to heart valve damage at high chronic doses in the ergot drug class. Whether AL-LAD shares this binding profile is unknown. safety citation needed

Receptor residence time

Wacker et al. solved the crystal structure of LSD bound to the serotonin 5-HT₂B receptor, revealing that a loop of protein (extracellular loop 2) forms a "lid" over the binding pocket that traps the molecule inside.^[16] AL-LAD shares the ergoline scaffold that engages this architecture, suggesting a similar trapping mechanism, but no specific data on AL-LAD's binding duration have been published.

Metabolism

Wagmann et al. investigated AL-LAD's metabolic breakdown using human liver preparations.^[12] The primary metabolizing enzymes are CYP1A2 and CYP3A4, with principal reactions including hydroxylation of the ergoline ring and removal of the allyl group. The parent compound was not detectable in rat urine at expected doses, indicating extensive metabolism before excretion.

Additional metabolic data came from studies of the prodrug 1P-AL-LAD, which confirmed AL-LAD as the most abundant metabolite and identified fourteen total metabolites of the combined system.^[11]

Where it acts

AL-LAD's psychedelic effects are driven by activation of 5-HT₂A receptors concentrated on layer V pyramidal neurons of the prefrontal cortex.^[4] This increases glutamate signaling in cortical and thalamic circuits, elevating excitability and disrupting the brain's normal filtering of sensory input.

The result — perceptual intensification, loosened cognitive boundaries, and altered self-awareness — mirrors the network-level changes observed with LSD and psilocybin, including disruption of the default mode network, the brain system most associated with the stable sense of self.

Why it matters

The REBUS (Relaxed Beliefs Under Psychedelics) framework offers the most explanatory model: 5-HT₂A activation reduces the brain's reliance on top-down predictions, allowing raw sensory information greater influence over conscious experience. This accounts for both the therapeutic potential (loosening rigid thought patterns) and the risk profile (destabilizing reality-testing in vulnerable individuals).

Serotonergic psychedelics including LSD also promote structural brain changes — increased dendritic spine density and new synaptic connections — through 5-HT₂A-dependent activation of growth factor pathways. Whether AL-LAD produces comparable neuroplasticity remains untested.

Toxicity

No lethal dose has been established for AL-LAD in any species, and no human fatalities have been attributed to the compound. The serotonergic psychedelic class is considered physiologically safe at recreational doses, with no established lethal dose in humans.^[6]

A separate concern applies to the ergoline class: chronic activation of serotonin₂B receptors by ergot-derived drugs is associated with heart valve damage. Whether AL-LAD shares LSD's 5-HT₂B binding profile is unknown; at typical patterns of infrequent use, this risk is considered minimal. safety citation needed

Psychological risks

The primary risks of AL-LAD are psychological. Acute distress — anxiety, panic, paranoia, and persecutory thoughts — is the most common adverse outcome of serotonergic psychedelic use. Kopra et al. found that emergency treatment following LSD use was predominantly for psychological distress rather than physiological toxicity.^[17]

Serotonergic psychedelics can precipitate or worsen psychotic episodes in individuals with personal or family history of psychotic spectrum disorders.^[18]

Hallucinogen persisting perception disorder (HPPD) is a rare outcome involving persistent visual disturbances after psychedelic use. Risk factors include pre-existing anxiety disorders and prior perceptual abnormalities.^[19] Leistenschneider et al. identified impaired visual memory and executive function in HPPD patients.^[20] No AL-LAD-specific HPPD cases have been reported.

Tolerance and dependence

Community estimates place the tolerance half-life at approximately 6 days and full reset at 14 days, though these values derive from self-report rather than controlled study. citation needed

Drug interactions

MAOIs — monoamine oxidase inhibitors prevent serotonin breakdown, creating potential for serotonin syndrome when combined with serotonergic agonists. safety citation needed

SSRIs/SNRIs — serotonin reuptake inhibitors may weaken psychedelic effects while simultaneously introducing serotonin syndrome risk. The net effect is unpredictable. safety citation needed

Contraindications

The following are based on class-level evidence for serotonergic psychedelics. No AL-LAD-specific contraindication data exist.

Absolute:

• Personal or family history of psychotic spectrum disorders (schizophrenia, schizoaffective disorder) — can precipitate or worsen psychotic episodes^[18]
• Concurrent lithium use — seizure risk safety citation needed

Relative:

• Heart conditions — transient increases in heart rate and blood pressure
• Concurrent tramadol use — serotonin syndrome risk^[21]
• Concurrent MAOI use — serotonin syndrome risk safety citation needed
• Pre-existing anxiety or mood disorders — increased risk of acute distress; may be a risk factor for HPPD^[19]
• Pregnancy — no safety data exist safety citation needed

AL-LAD is not scheduled under the United Nations Convention on Psychotropic Substances and occupies a varied legal position across national jurisdictions. Several countries have specifically named AL-LAD in controlled substance legislation since 2015, while others rely on structural analog provisions or have not addressed the compound at all.^[23]

The legal landscape for novel lysergamides continues to evolve. AL-LAD's emergence on the NPS market in 2013^[4] preceded its specific scheduling in the UK and Sweden by one to three years, illustrating the reactive nature of NPS scheduling. The prodrug 1P-AL-LAD was developed in part as a response to AL-LAD scheduling, exploiting regulatory gaps around 1-acyl-substituted lysergamide derivatives.^[11]