Metabolites
November 12, 2021
Jitka Nykodemová, Anna Šuláková, Petr Palivec et al.
14 citations
The metabolism of the psychoactive compound 2C-B-Fly-NBOMe was investigated using three systems: human liver microsomes, the fungus Cunninghamella elegans, and live rats. Thirty-five phase I and nine phase II metabolites were identified. Major metabolic pathways include hydroxylation, O-demethylation, oxidative debromination, and N-demethoxybenzylation, followed by glucuronidation or N-acetylation. Human liver microsomes produced the most metabolites at highest concentrations. Two poly-hydroxylated metabolites appeared only in rat urine, while the fungus generated dehydrogenated, N-oxygenated, and dibrominated metabolites. These findings clarify how the body processes this substance, aiding understanding of its effects and potential toxicity.
British journal of pharmacology
January 1, 2022
Kristýna Štefková-mazochová, Hynek Danda, Wim Dehaen et al.
13 citations
Deschloroketamine (DCK), a structural analogue of ketamine sold as a recreational drug, was tested in Wistar rats to examine its pharmacokinetics, acute effects, and addictive potential. DCK rapidly entered the brain, with peak levels at 30 minutes and sustained high levels for 2 hours. It blocks NMDA receptors similarly to ketamine, with the S-enantiomer more potent. DCK stimulated locomotion, induced place preference (a sign of reward), and strongly disrupted prepulse inhibition (PPI). Locomotor stimulation faded faster than PPI disruption. S-DCK had stronger stimulatory effects than R-DCK, but both equally disrupted PPI. DCK's behavioral and addictive profiles resemble ketamine's, with a slightly slower clearance, matching its reported longer duration. These findings clarify risks of illicit DCK use.
Addiction Biology
May 7, 2020
Nikola Pinterová, Rachel R. Horsley, Hynek Danda et al.
13 citations
Naphyrone, a synthetic cathinone similar to pyrovalerone, potently blocks monoamine transporters and produces stimulant and entactogen-like effects. In male Wistar rats, a single subcutaneous dose of 1 mg/kg reached peak concentrations in blood and tissues within 30 minutes, with prolonged elevation in the brain relative to serum. A higher dose of 20 mg/kg caused modest increases in body temperature and lasting hyperactivity in an open field test, while transiently improving sensorimotor gating as measured by prepulse inhibition. No acute toxicity was observed. The drug crosses the blood-brain barrier rapidly and is eliminated slowly, with effects matching its pharmacokinetics. Harm-reduction guidance should follow that for other stimulants and cathinones.
Elsevier eBooks
January 1, 2016
Filip Tylš, Tomáš Páleníček, Jiřı́ Horáček
13 citations
Psilocybin, a hallucinogen derived from mushrooms, showed remarkable effects in a sample of 200 participants suffering from depression. After treatment, 67% experienced significant reductions in depressive symptoms within just two weeks. This compound influences neurotransmitter receptors, particularly serotonergic pathways, which are crucial in psychiatry and psychology. The study highlights psilocybin's potential as a transformative agent in medicine, offering hope for those seeking effective alternatives to traditional antidepressants. Its unique chemical synthesis and alkaloid properties could reshape the landscape of mental health treatment.
Drug Testing and Analysis
October 31, 2019
Kateřina Hájková, Bronislav Jurásek, Jan Čejka et al.
12 citations
Deschloroketamine, a ketamine analog sold illicitly since 2015 and sometimes misrepresented as ketamine, has potential antidepressant properties. A metabolomics study used liquid chromatography–high-resolution mass spectrometry and a validated multiple reaction monitoring method to track its metabolites in urine, serum, and brain tissue. Key metabolites—trans-dihydrodeschloroketamine, cis- and trans-dihydronordeschloroketamine, and nordeschloroketamine—were synthesized and used as standards. In serum, nordeschloroketamine and deschloroketamine concentrations ranged from 0.5 to 860 ng/mL; in brain tissue, they ranged from 0.5 to 4700 ng/g. The quantification methods showed intra-day accuracy of 80–125% and precision averaging 3–7%.
Journal of Fungi
January 28, 2025
Eyal Kurzbaum, Tomáš Páleníček, Amiel Shrchaton et al.
11 citations
The psychoactive mushroom Psilocybe cubensis, known for its historical and modern therapeutic roles, shows substantial variability in its psychoactive compounds, psilocybin and psilocin, due to genetic diversity, strain differences, and environmental factors. Advances in cultivation, such as submerged fermentation of mycelium, and improved analytical methods now allow more precise compound quantification and extraction. Despite nearly four decades of regulatory restrictions limiting scientific information, recent genetic and biochemical studies are beginning to reveal insights into its therapeutic potential. The review identifies key knowledge gaps and suggests future research directions to improve cultivation, document strain diversity, and address regulatory and therapeutic uses.
Metabolites
March 31, 2021
Anna Šuláková, Jitka Nykodemová, Petr Palivec et al.
11 citations
N-Benzylphenethylamines, including 25CN-NBOMe, are novel psychedelic substances with limited metabolism data. This study investigated the metabolic profile of 25CN-NBOMe in rats in vivo and in human liver microsomes and Cunninghamella elegans mycelium in vitro. Major metabolic pathways include mono- and bis-O-demethylation, hydroxylation, and combinations, followed by glucuronidation, sulfation, or N-acetylation of primary metabolites. The cyano group was either hydrolyzed to an amide or carboxylic acid or remained unchanged. Differences between species should be considered in metabolism studies of novel substances.
Journal of Neurochemistry
February 28, 2025
Aneta Petrušková, Debarpan Guhathakurta, Enes Yağız Akdaş et al.
8 citations
Serotonergic psychedelics like psilocybin, LSD, and DMT rapidly alter how neurons communicate at synapses. Using live-cell imaging in rat cortical neurons, the drugs reduced the fraction of synaptic vesicles that fuse in response to electrical stimulation within minutes, an effect that faded within 24 hours. DMT only reduced the total recycling pool of vesicles, while LSD and psilocin also shrank the readily releasable pool. Psilocin and DMT increased evoked glutamate release, yet LSD and psilocin lowered presynaptic calcium levels. Psilocin further depressed responses to paired stimuli. These drug-specific modulations of glutamatergic transmission may help explain their distinct therapeutic properties.
Addiction Biology
August 4, 2022
Klára Šíchová, Kateřina Syrová, Edita Kofroňová et al.
8 citations
25CN-NBOMe, a substance related to LSD, readily crosses the blood-brain barrier in rats. After a 5 mg/kg dose, drug concentration peaked in blood and brain at 1 hour, with half-lives of 1.88 and 2.28 hours. The drug is classified as toxicity category 3, with a lethal dose of 300 mg/kg and an estimated LD50 of 200 mg/kg. Histological findings suggest acute cardiovascular arrest from malignant arrhythmia at lethal doses. A 5 mg/kg dose reduced body temperature in individually housed rats. Lower doses (0.2 and 1 mg/kg) reduced locomotor activity and increased anxiety, while 5 mg/kg also impaired sensorimotor gating. The drug's behavioral effects are comparable to other NBOMes.
Adaptive Behavior
April 4, 2018
Tom Froese, Iwin Leenen, Tomáš Páleníček
8 citations
After a long pause, research into serotonergic psychedelics as treatments has revived; controlled administration can produce lasting positive psychological changes, though the mechanisms are unclear. This paper highlights an underexplored possibility: that these benefits may arise from a beneficial interaction with sleep's self-optimizing functions.
medRxiv
September 11, 2024
M. Nikolič, Pedro A. M. Mediano, Tom Froese et al.
6 citations
preprint
Psilocybin, a classic psychedelic, alters perception, cognition, and emotion by activating 5-HT2A receptors and reducing serotonin reuptake. In a placebo-controlled crossover study with 20 healthy individuals, electroencephalography tracked brain activity changes over 24 hours after oral psilocybin (0.26 mg/kg). Acutely, absolute power decreased in alpha and beta bands but increased in delta and gamma frequencies; alpha power decreased occipitally between 1 and 3 hours, and beta decreased frontally at 3 hours. Global functional connectivity in the alpha band dropped acutely, while Lempel-Ziv complexity increased at 1 and 1.5 hours.
Xenobiotica
July 12, 2016
Monika Židková, Igor Linhart, Marie Balı́ková et al.
6 citations
The drug 5,6-Methylenedioxy-2-aminoindane (MDAI), a serotoninergic aminoindane sold as a substitute for banned stimulants and entactogens, is metabolized in rats primarily through oxidative demethylenation followed by O-methylation and N-acetylation, producing five main metabolites found as glucuronides and sulphates. Most of the administered MDAI was excreted unchanged. Minor metabolites formed by hydroxylation include cis- and trans-1-hydroxy- and 4-hydroxy derivatives. Identification of most metabolites was confirmed with synthesized reference standards.
The International Journal of Neuropsychopharmacology
May 27, 2016
Tomáš Páleníček, Filip Tylš, Michaela Viktorinová et al.
6 citations
No Summary
Journal of Psychopharmacology
September 12, 2025
Stephan Tap, Kelan Thomas, Tomáš Páleníček et al.
5 citations
Classic psychedelics like psilocybin are being studied for psychiatric disorders. Current protocols typically require patients to stop antidepressants (ADs) for at least two weeks before psychedelic use to avoid serotonin syndrome and preserve efficacy, but discontinuation can worsen depression and increase suicidal ideation. This scoping review of 18 studies found that using ADs alongside classic psychedelics is generally safe and tolerable, with no increased risk of serotonin syndrome, especially with psilocybin. Some studies showed significant improvements in depression and other symptoms. Although some evidence suggests a potential reduction in acute subjective psychedelic effects, this was not consistent. The authors conclude that maintaining ADs may improve patient access and avoid discontinuation risks.
Pharmacology, biochemistry, and behavior
December 1, 2024
Lucie Olejníková-Ladislavová, Michaela Fujáková-Lipski, Klára Šíchová et al.
5 citations
Mescaline, a classical psychedelic, primarily acts on serotonin 5-HT2A/C receptors but also binds to 5-HT1A and 5-HT2B receptors. In adult male rats, the highest dose (100 mg/kg) caused hyperlocomotion, which was reversed by almost all antagonists tested. Sensorimotor gating deficits, measured as prepulse inhibition of acoustic startle, were selectively normalized by a 5-HT2A antagonist, while a 5-HT2C antagonist partially reversed deficits from lower doses. These findings indicate that mescaline's behavioral effects are mainly mediated by the 5-HT2A receptor subtype, with a lesser role for 5-HT2C receptors, and limited involvement of other subtypes.
Biological psychiatry global open science
September 1, 2025
Čestmír Vejmola, Klára Šíchová, Kateřina Syrová et al.
4 citations
Psilocin, the active compound in psychedelic mushrooms, impairs the ability to distinguish between static and moving images in both humans and rats. In a visual discrimination task, human participants and male rats were asked to judge whether an image was static or moving. Under psilocin, both species showed significant difficulty in this task. In humans, the impairment tracked psilocin plasma levels and self-reported hallucination intensity. In rats, psilocin selectively disrupted performance in a motion-based task but not a luminance-based task, suggesting a specific effect on motion perception. Decision time was also linked to discrimination impairment. This is the first evidence that rats experience visual distortions similar to those reported by humans, offering a model for studying altered visual perception in drug-induced and psychiatric conditions.
Frontiers in Neuroscience
July 1, 2025
Michal Beneš, Tomáš Páleníček, Jiřı́ Horáček
4 citations
A scoping review of fMRI studies on serotonergic psychedelics (psilocybin, LSD, DMT) identifies unifying themes: de-differentiation centered on the default mode network, complex changes in the thalamus, amygdala, and medial temporal lobe, and the importance of ego dissolution. These findings complement established models of psychedelic action and highlight contrasts with phenomenologically similar states and links to other biological markers.
Pharmacological reports : PR
June 16, 2025
Tereza Klučková, Marek Nikolič, Filip Tylš et al.
4 citations
In healthy individuals, psilocybin produces lasting positive effects regardless of previous psychedelic experience, repeated use, setting, sex, or occupation. In a double-blind, placebo-controlled crossover study with 40 participants (20 females, mean age 38), each received two doses of psilocybin (0.26 mg/kg) at least 56 days apart. Acute effects were moderate on the Altered States of Consciousness Scales, with mostly pleasant or fluctuating experiences and only one unpleasant session; all sessions ended positively or neutrally. Long-term effects, assessed by the Persisting Effects Questionnaire, were positive across all domains with negligible negative effects. Peak experiences ending in a positive mood strongly predicted favorable long-term outcomes, while challenging experiences did not cause adverse outcomes. These findings support psilocybin's psychological safety and repeated use in clinical trials.
Journal of psychopharmacology (Oxford, England)
June 10, 2025
Torsten Passie, Anja Loizaga-Velder, Alicia Danforth et al.
4 citations
A consensus-based model curriculum for education and training in substance-assisted psychotherapy (SAP) covers theoretical topics and practical components including apprenticeship observation, ongoing clinical supervision, and self-experience for trainees. The model, developed by authors with extensive SAP experience, also addresses peer and conventional supervision, respect for intercultural differences, and teachings about indigenous use of related substances. It is largely adapted to western industrialized countries with established graduate-level psychotherapy training. The curriculum may be valuable for psychedelic researchers, those training therapists for research studies, and those preparing for clinical work outside research settings.
Frontiers in pharmacology
January 1, 2023
Kateřina Syrová, Klára Šíchová, Hynek Danda et al.
4 citations
2C-B-Fly-NBOMe, a new psychoactive substance related to the psychedelic entactogen 2C-B, was studied in adult male Wistar rats. After injection, peak drug levels in blood serum occurred at 30 minutes (28 ng/ml) and in brain tissue at 60 minutes (171 ng/g), with the compound still detectable in the brain after 8 hours. The drug dose-dependently reduced locomotor activity and strongly disrupted the acoustic startle response, with a weaker effect on prepulse inhibition. It did not cause significant changes in body temperature. The overall profile resembles that of 2C-B and other NBOMe substances, suggesting slow brain penetration and inhibitory effects on motor performance and sensorimotor gating.
JAMA Psychiatry
March 25, 2026
Wiesław Jerzy Cubała, Malek Bajbouj, Michael Bauer et al.
3 citations
A single day of treatment with an inhaled synthetic formulation of mebufotenin (GH001) significantly reduced depression symptoms in adults with treatment-resistant depression compared to placebo. In a randomized, double-blind trial of 81 patients, those receiving up to three escalating doses of GH001 showed an average 15.5-point greater improvement on the Montgomery-Åsberg Depression Rating Scale by day 8 than those on placebo. Remission rates were 57.5% for GH001 and 0% for placebo. No severe or serious adverse events occurred. The findings suggest GH001 may be a rapid-acting, well-tolerated treatment option for treatment-resistant depression.
Progress in neuro-psychopharmacology & biological psychiatry
March 20, 2025
Kristýna Štefková-mazochová, Hynek Danda, Vladimír Mazoch et al.
3 citations
Methoxphenidine (MXP), a new psychoactive substance, rapidly crosses the blood-brain barrier in Wistar rats, reaching peak concentrations in serum and brain 30 minutes after injection, with a half-life of 2.15 hours. Low to moderate doses (10-20 mg/kg) increase locomotor activity in an open field test, while a higher dose (40 mg/kg) decreases it. All doses disrupt sensorimotor gating (prepulse inhibition), an effect linked to psychosis. MXP shows moderate acute toxicity with an estimated LD50 of 500 mg/kg subcutaneously. The drug exhibits a profile similar to dissociative anesthetics, producing stimulant and anxiogenic effects at lower doses and sedative effects at higher doses, indicating risks of serious adverse health outcomes from recreational use.
Journal of affective disorders
August 1, 2026
Guy M Goodwin, Scott T Aaronson, Oscar Alvarez et al.
2 citations
In people with treatment-resistant depression receiving 25 mg psilocybin with monitoring and support, the therapeutic alliance before dosing had only weak correlations with improvement in depression scores at three weeks. Stronger correlations were seen with the intensity of the psychedelic experience itself, particularly emotional breakthrough and visual restructuring. Path analysis suggested that therapeutic alliance helped facilitate the psychedelic experience, but it was the psychedelic experience—not the alliance—that had stronger direct effects on clinical outcomes. The alliance's direct effect on antidepressant response was limited or absent.
medRxiv
August 26, 2024
Tereza Klučková, Filip Tylš, Vojtěch Viktorin et al.
2 citations
preprint
In healthy volunteers, two doses of psilocybin (0.26 mg/kg) given at least 56 days apart produced moderate acute psychedelic effects that were mostly pleasant or fluctuating, with only one unpleasant experience. All sessions ended in a positive or neutral state. Psilocybin led to sustained positive effects across all domains of the Persisting Effects Questionnaire, with negligible negative effects. Contrary to expectations, dread of ego dissolution was not linked to negative long-term outcomes. Peak experiences culminating in positive mood were associated with positive lasting effects, while the type of experience (pleasant or mixed) did not correlate with the intensity or direction of the lasting effect. Results were independent of previous psychedelic experience, sex, or study setting.
The international journal of neuropsychopharmacology
August 1, 2025
Klára Šíchová, Barbara Mallarino, Lucie Janeckova et al.
1 citation
Hexahydrocannabinol (HHC), a new psychoactive substance used as a legal alternative to ∆9-tetrahydrocannabinol, crosses the blood-brain barrier, exhibits mild toxicity, and induces behavioral effects similar to tetrahydrocannabinol in male Wistar rats. A 1:1 mixture of (9R)-HHC and (9S)-HHC was given at doses of 1, 5, and 10 mg/kg. Two hours after the highest dose, peak concentrations appeared in blood and brain tissue. The OECD 423 test classified HHC as Category 4, with an estimated lethal dose of 1000 mg/kg. Compared to controls, 10 mg/kg HHC reduced movement, increased anxiety, and impaired sensory processing, highlighting dose-dependent anxiogenic properties and impact on information processing.