May 2026
Serotonin
What May 2026's 13 new studies found, synthesized from the papers below. All Serotonin research →
The synthesis
Synthesized from 13 studies in the library · AI-generated, grounded in the abstracts below
Found by searching the library for Serotonin, 5-HT, serotonergic, 5-HT2A receptor, then ranked by relevance.
Research published in May 2026 on serotonin spans diverse topics, including psychedelic mechanisms, therapeutic potential, and safety risks. Findings are mixed: some studies support anxiolytic and antidepressant effects of serotonergic psychedelics, while others highlight risks like serotonin syndrome and valvular heart disease. The evidence is largely preclinical or theoretical, with small human samples, and long-term durability and clinical translation remain unclear.
Evidence by study
Direction is which way each study's own result points, not our rating of the study.
What the directions mean
- Supports:
- the study found the intervention worked, or its hypothesis held.
- Opposes:
- it found the opposite, no benefit or a harm.
- No effect:
- no significant difference either way.
- Mixed:
- effects in both directions within the same study.
- Unclear:
- the abstract does not report a direction.
| Study | Design | Sample size | Direction | Finding |
|---|---|---|---|---|
| Inhibition of compulsive behavior by dextromethorphan on schedule-induced polydipsia in rats: Role of NMDA, sigma-1, and 5-HT receptors. 2026 | preclinical experimental study | Supports | Dextromethorphan dose-dependently reduced compulsive-like water consumption in rats, suggesting potential for OCD treatment. | |
| A systematic review of the pharmacokinetics of classical serotonergic psychedelic compounds in healthy adult subjects. 2026 | systematic review | 32 | Unclear | The review summarized pharmacokinetic data for classical psychedelics, noting dose-proportional Cmax for LSD and psilocybin and clinically significant differences between oral and IV DMT. |
| A spatiotemporal gating hypothesis for psilocybin plasticity: reconciling the 5-HT₂A-TrkB mechanistic paradox. 2026 | theoretical | Unclear | Argues that psilocybin's plasticity effects are explained by a spatiotemporal gating mechanism coordinating 5-HT2A and TrkB signaling. | |
| The Serotonin 2B (5‐ HT2B ) Receptor: A Narrative Review of Preclinical and Clinical Evidence on the Safety Considerations and Therapeutic Potential for the Treatment of Depression 2026 | narrative review | Mixed | The review concludes that peripheral 5-HT2B agonism is linked to valvular heart disease, while central antagonism may be a therapeutic target for depression, but cumulative psychedelic exposure risks are insufficiently characterized. | |
| Serotonin Transporter Blockade Reduces the Psychedelic-Like Effects of 4-Methoxy- N -methyl- N -isopropyltryptamine and Related Analogs 2026 | preclinical experimental study | Supports | Compounds with potent SERT inhibition showed reduced psychedelic-like effects in mice, supporting the hypothesis that SERT blockade attenuates 5-HT2A-mediated responses. | |
| Serotonergic Psychedelics as a Potential Therapeutic Strategy for Anxiety, A Systematic Review 2026 | systematic review | 18 | Mixed | Serotonergic psychedelics showed anxiolytic-like effects in some animal models but also anxiogenic and null effects, indicating context-dependence. |
| N -Benzyl-Tryptamine Derivatives as Serotonin 5-HT 2 Receptor Ligands: Synthesis and Structure-Affinity/Activity Relationships 2026 | experimental study with QSAR analysis | Supports | Meta-substitution of N-benzyltryptamines enhanced 5-HT2 receptor activity, while para-substitution reduced it due to steric clashes. | |
| Psilocybin in Older Adults: Therapeutic Opportunities in Inflammation-Driven Disorders of Aging-From Depression to Neurodegeneration. 2026 | review | Supports | Psilocybin shows potential as a multimodal therapeutic for inflammation-related disorders in aging, with rapid antidepressant and anxiolytic effects and a favorable pharmacokinetic profile. | |
| 5‐HT 2A receptor agonism by tert ‐leucinamide and valinamide synthetic cannabinoids: In vitro and in vivo evidence 2026 | experimental study (in vitro and in vivo) | Supports | Synthetic cannabinoids with valinamide or tert-leucinamide moieties activate 5-HT2A receptors, and AB-5'F-BUTINACA's effects are mediated by both CB1 and 5-HT2A receptors. | |
| 5-HT1A receptor blockade potentiates the subjective effects of DMT. 2026 | double-blind, randomized, placebo-controlled within-subjects design | 12 | Supports | 5-HT1A blockade with pindolol increased DMT-induced subjective effects with a moderate effect size. |
| The serotonin 1B receptor is required for some of the behavioral effects of psilocybin in mice. 2026 | experimental study | Supports | The 5-HT1B receptor is required for some behavioral effects of psilocybin, including hypolocomotion and persisting antidepressant-like effects. | |
| B48-13 Severe Serotonin Syndrome With Acute Respiratory Failure Following Ayahuasca and Dextromethorphan Use: A Case Report 2026 | case report | 1 | Opposes | Ayahuasca combined with dextromethorphan and diphenhydramine triggered severe serotonin syndrome with respiratory failure, requiring intubation and ICU care. |
| Serotonergic psychedelics as epigenetic modulators: A paradigm shift in Alzheimer's disease therapeutics. 2026 | review | Supports | Argues that targeted engagement of 5-HT2A receptors may counteract epigenetic abnormalities contributing to Alzheimer's disease pathogenesis. |
Dextromethorphan dose-dependently reduced compulsive-like water consumption in rats, suggesting potential for OCD treatment.
preclinical experimental study
The review summarized pharmacokinetic data for classical psychedelics, noting dose-proportional Cmax for LSD and psilocybin and clinically significant differences between oral and IV DMT.
systematic review Sample size: 32
Argues that psilocybin's plasticity effects are explained by a spatiotemporal gating mechanism coordinating 5-HT2A and TrkB signaling.
theoretical
The review concludes that peripheral 5-HT2B agonism is linked to valvular heart disease, while central antagonism may be a therapeutic target for depression, but cumulative psychedelic exposure risks are insufficiently characterized.
narrative review
Compounds with potent SERT inhibition showed reduced psychedelic-like effects in mice, supporting the hypothesis that SERT blockade attenuates 5-HT2A-mediated responses.
preclinical experimental study
Serotonergic psychedelics showed anxiolytic-like effects in some animal models but also anxiogenic and null effects, indicating context-dependence.
systematic review Sample size: 18
Meta-substitution of N-benzyltryptamines enhanced 5-HT2 receptor activity, while para-substitution reduced it due to steric clashes.
experimental study with QSAR analysis
Psilocybin shows potential as a multimodal therapeutic for inflammation-related disorders in aging, with rapid antidepressant and anxiolytic effects and a favorable pharmacokinetic profile.
review
Synthetic cannabinoids with valinamide or tert-leucinamide moieties activate 5-HT2A receptors, and AB-5'F-BUTINACA's effects are mediated by both CB1 and 5-HT2A receptors.
experimental study (in vitro and in vivo)
5-HT1A blockade with pindolol increased DMT-induced subjective effects with a moderate effect size.
double-blind, randomized, placebo-controlled within-subjects design Sample size: 12
The 5-HT1B receptor is required for some behavioral effects of psilocybin, including hypolocomotion and persisting antidepressant-like effects.
experimental study
Ayahuasca combined with dextromethorphan and diphenhydramine triggered severe serotonin syndrome with respiratory failure, requiring intubation and ICU care.
case report Sample size: 1
Argues that targeted engagement of 5-HT2A receptors may counteract epigenetic abnormalities contributing to Alzheimer's disease pathogenesis.
review
Points of agreement
- Multiple studies highlight the importance of 5-HT2A receptor agonism in mediating psychedelic effects and potential therapeutic actions.
- Several reviews and preclinical studies suggest serotonergic psychedelics may have anxiolytic and antidepressant potential.
- Pharmacokinetic and safety considerations are emphasized across studies, including risks of serotonin syndrome and valvular heart disease.
Conflicts
- Some studies report anxiolytic effects of psychedelics, while others report anxiogenic or null effects.
- The role of 5-HT1A receptor in psychedelic effects is debated: one study found blockade potentiates DMT effects, while another suggests 5-HT1B is important for psilocybin effects.
- There is a paradox regarding 5-HT2A and TrkB signaling in psilocybin plasticity, with a proposed gating hypothesis to reconcile it.
Gaps
- Long-term durability of therapeutic effects is not addressed in most studies.
- Human data are limited, with small sample sizes and mostly preclinical or theoretical work.
- Dose-response relationships and optimal dosing regimens are not fully characterized.
- Safety data on cumulative psychedelic exposure and interactions with other serotonergic agents are insufficient.
- The role of specific serotonin receptor subtypes in mediating therapeutic versus adverse effects requires further investigation.