Analytical and behavioral characterization of N-ethyl-N-isopropyllysergamide (EIPLA), an isomer of N6 -ethylnorlysergic acid N,N-diethylamide (ETH-LAD).
Simon D. Brandt, Pierce V. Kavanagh, Folker Westphal, Benedikt Pulver, Hannes M Schwelm, Alexander Stratford, Volker Auwärter, Adam L. Halberstadt
Drug Testing and Analysis February 1, 2024 DOI: 10.1002/dta.3530 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Preclinical study Peer reviewed |
|---|---|
| Population | Mice |
| Intervention | EIPLA |
| Dose | ED50 = 234.6 nmol/kg |
| Topics | LSD |
| Keywords | Blotters New psychoactive substances Psychedelics Research chemicals Serotonergic drugs Drug testing Pharmacology |
| Citations | 5 |
| Key points | EIPLA induces head-twitch responses in mice at about half the potency of LSD, consistent with serotonergic psychedelic activity. |
Abstract
Preclinical investigations have shown that N-ethyl-N-isopropyllysergamide (EIPLA) exhibits lysergic acid diethylamide (LSD)-like properties, which suggests that it might show psychoactive effects in humans. EIPLA is also an isomer of N6 -ethylnorlysergic acid N,N-diethylamide (ETH-LAD), a lysergamide known to produce psychedelic effects in humans that emerged as a research chemical. EIPLA was subjected to analysis by various forms of mass spectrometry, chromatography (GC, LC), nuclear magnetic resonance (NMR) spectroscopy, and GC condensed-phase infrared spectroscopy. The most straightforward differentiation between EIPLA and ETH-LAD included the evaluation of mass spectral features that reflected the structural differences (EIPLA: N6 -methyl and N-ethyl-N-isopropylamide group; ETH-LAD: N6 -ethyl and N,N-diethylamide group). Proton NMR analysis of blotter extracts suggested that EIPLA was detected as the base instead of a salt, and two blotter extracts suspected to contain EIPLA revealed the detection of 96.9 ± 0.5 μg (RSD: 0.6%) and 85.8 ± 2.8 μg base equivalents based on LC-MS analysis. The in vivo activity of EIPLA was evaluated using the mouse head-twitch response (HTR) assay. Similar to LSD and other serotonergic psychedelics, EIPLA induced the HTR (ED50 = 234.6 nmol/kg), which was about half the potency of LSD (ED50 = 132.8 nmol/kg). These findings are consistent with the results of previous studies demonstrating that EIPLA can mimic the effects of known psychedelic drugs in rodent behavioral models. The dissemination of analytical data for EIPLA was deemed justifiable to aid future forensic and clinical investigations.
Comparable studies
Other preclinical and animal studies on LSD, most cited first.
Citations in the library
Cited by 3
- Psychedelic Drug Checking: Analytical and Strategic Challenges in Harm Reduction for Classic Psychedelics Current Topics in Behavioral Neurosciences 2025
- Structural analysis of an lysergic acid diethylamide (LSD) analogue N-methyl-N-isopropyllysergamide (MiPLA): Insights from Rotamers in NMR spectra. Drug Testing and Analysis June 1, 2024
- Short- and Long-Acting Psychedelics: Structure-Activity Relationships, Pharmacology, and Implications for Neuropsychiatric Therapeutics. ACS Chemical Neuroscience June 17, 2026
Cites 19
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- Correlation between the potency of hallucinogens in the mouse head-twitch response assay and their behavioral and subjective effects in other species. Neuropharmacology May 1, 2020
- The History of Psychedelics in Psychiatry Pharmacopsychiatry December 7, 2020
- Effect of Hallucinogens on Unconditioned Behavior Current Topics in Behavioral Neurosciences 2016
and 14 more in the library