ETH-LAD, or N6-ethyl-6-norlysergic acid diethylamide, is a lysergamide structurally related to LSD. It differs from LSD by replacing the N6-methyl group with an ethyl group. The compound was synthesised in the 1970s and has been described as producing LSD-like effects in humans. Analytical studies have since confirmed its presence in blotter products, and a 2026 case report documented a severe intoxication with analytically confirmed exposure.
Chemistry and history
ETH-LAD retains the ergoline skeleton and N,N-diethylamide group of LSD, but carries an ethyl rather than methyl substituent at N6. It is therefore an N6-alkyl lysergamide, not an N1-acyl derivative such as 1P-LSD or 1cP-LSD.
The synthesis of ETH-LAD was first reported in 1976. It later appeared on the new psychoactive substance market in blotter form. A 2017 study provided a detailed analytical characterisation using mass spectrometry, chromatography, infrared spectroscopy and NMR (Brandt and colleagues, 2017).
Pharmacology
ETH-LAD has high affinity for the 5-HT2A receptor. Published receptor studies report a Ki of approximately 5.1 nM. Binding has also been reported at dopamine D1 and D2 receptors. In animal drug-discrimination studies, ETH-LAD produced full substitution in rats trained to recognise LSD, and some early experiments found greater potency than LSD in that specific model (Hoffman and Nichols, 1985).
Historical human descriptions also report psychedelic effects similar to LSD. However, the number of controlled human studies is small, and animal potency comparisons should not be treated as direct measures of human potency.
Reported effects
Descriptions in historical and more recent reports include changes in visual perception, thought and mood. The 2026 case report notes that informal accounts have described strong visual effects, introspection and physical discomfort, but these accounts are anecdotal and cannot define a predictable clinical profile.
Clinical and forensic findings
In August 2026, researchers published the first case report with analytically confirmed ETH-LAD exposure. A 17-year-old patient developed severe agitation, aggression, unconsciousness, traumatic injuries, metabolic disturbances and persistent psychosis. ETH-LAD was measured in serum approximately eight hours after the reported exposure. The patient required intensive treatment and was hospitalised for 17 days before transfer to psychiatric care (Nadler and colleagues, 2026).
The case also involved cannabis and low concentrations of other substances. The authors assessed the causal relationship as conditional rather than definitive. The case raises clinical concerns, but cannot establish how often severe reactions occur or a general concentration-toxicity threshold.
Research limitations
Despite historical human reports and established receptor activity, ETH-LAD’s human pharmacokinetics remain poorly characterised. The 2026 case report specifically cautions against simply inferring its absorption, distribution or elimination from LSD data. Long-term effects and dependence potential also remain uncertain.
Related lysergamides
ETH-LAD is related to AL-LAD, 1P-ETH-LAD, LSD and other N6-substituted lysergamides. Its N6-ethyl group distinguishes it from the N6-allyl structure of AL-LAD.
