In brief
- A team at the University of Arkansas for Medical Sciences (UAMS) tested four LSD analogs circulating in the gray market: 1A-LSD, 1P-LSD, 1B-LSD, and 1cP-LSD.
- All four showed lower affinity and/or efficacy in serotonin-receptor assays but fully substituted for LSD in rat behavioral discrimination.
- Blood tests revealed LSD levels similar to those found after taking LSD itself, indicating the body transforms these compounds into LSD.
- A fifth compound tested, LSZ, did not convert into LSD; it acts on the same receptors independently.
- The study, published in July 2026, was conducted on rats; caution is required when extrapolating these findings to humans.
A study published in July in the Journal of Pharmacology and Experimental Therapeutics examines four N1 LSD analogs in rats: 1A-LSD, 1P-LSD, 1B-LSD and 1cP-LSD. Detectable blood LSD after administration is consistent with conversion in that model. The findings, authored by Michael Berquist, William Fantegrossi, and their team at UAMS, connect laboratory profiles with a rat behavioral assay, without establishing identical human experiences.
Four molecules, one result
The abstract places these analogs in the gray market, but altering a structure does not establish that a product is outside each jurisdiction’s controls. The researchers compared five of these compounds with original LSD on three fronts: their affinity for 5-HT1A, 5-HT2A, 5-HT2B, and 5-HT2C serotonin receptors; their ability to substitute for LSD in a behavioral discrimination test with rats trained to recognize it; and their presence in the blood following injection.
In test tubes, the four N1-substituted analogs showed lower affinity or weaker efficacy than LSD at these receptors. Even so, in live animals, all four fully substituted for LSD: the rats recognized them as if they were the substance they had been trained to identify.
Blood reveals the reason
The answer emerged when analyzing the animals’ blood after injection: at the times relevant to the behavioral test, the levels of LSD detected were similar regardless of which analog had been administered. The body removes the chemical group added to the N1 nitrogen and releases LSD. In practice, these four analogs act as prodrugs for LSD.
The exception was LSZ, an analog with a substitution on the diethylamide portion rather than the indole nitrogen. This compound showed affinity for serotonin receptors similar to that of LSD itself, did not transform into LSD after injection, and produced its effects as an independent molecule.
Implications
The experiment cannot establish an equivalent human dose or effect duration. The authors suggest that human metabolic variation could affect responses, but did not measure those differences in human participants. Appropriate harm reduction must avoid extrapolating these rat findings to equivalent human doses or effect duration.
The research team notes the study’s limitations: it was conducted on rats using systemic injection rather than oral or sublingual administration, which is how these products are typically consumed in real-world settings. The findings are consistent with conversion to LSD in rats but do not quantify conversion or duration in people.
Source
- Berquist MD, Gannon BM, Honeywell KM, et al. Interoceptive effects of N1-substituted lysergamides in rats: role of agonist affinity at 5-hydroxytryptamine receptors and in vivo metabolism to lysergic acid diethylamide. Journal of Pharmacology and Experimental Therapeutics, July 2026.
Educational content written from a harm reduction perspective and with respect for individual freedom. It is not a substitute for advice from a healthcare professional and is not intended to encourage or condemn any drug use.
