We introduce five scientific pillars to systematically evaluate psychedelics and neuroplastogens, from receptor pharmacology to clinical outcomes. These pillars offer a framework to compare these modalities without bias, clarifying how each translates biological effects into therapeutic potential.
The psychedelic therapeutics landscape has expanded beyond classic serotonergic psychedelics such as 5-HT2A agonist agents like psilocybin (COMP360) and LSD, to include LSD-formulations like MindMed’s MM-120, entactogens such as Lykos Therapeutics’ midomafetamine (MDMA-HCl), NMDA-channel modulators such as esmethadone (REL-1017) from Relmada Therapeutics, Inc, R-ketamine originally characterized by Kenji Hashimoto’s group in Japan, sigma-1 receptor agonists such as igmesine first developed by Sanofi, and a new generation of non-hallucinogenic neuroplastogens such as Delix Therapeutics’ DLX-001/DLX-007 and Gilgamesh Pharma’s GM2505.
To compare such different modalities, it is useful to rely on five scientific pillars that clarify how these drugs engage biology and what kinds of data truly signal therapeutic potential. The pillars apply to both psychedelics and neuroplastogens, though each class expresses them differently.
The first pillar is mechanistic pharmacology. Psychedelics act through strong activation of the 5-HT2A receptor, which drives the Gq/11 signaling cascade and produces the altered-state experience. Neuroplastogens aim to preserve the plasticity without the hallucinogenic signal. Some do this with lower-efficacy or biased 5-HT2A activation, while others rely on entirely different systems such as TrkB, sigma-1, NMDA, or muscarinic M1 pathways. The distinction between these mechanisms rests on clear and reliable readouts: binding affinity, intrinsic efficacy, β-arrestin recruitment, calcium signaling, receptor occupancy, residence time, off-target profiling such as 5-HT2B or hERG, and in rodents the head-twitch response, which remains the standard proxy for hallucinogenic liability.
The second pillar is pharmacokinetics and pharmacodynamics. Psychedelics show a clear relationship between plasma exposure, onset of subjective intensity, and early clinical effects; the drug rises in the bloodstream, the acute experience unfolds, and network-level changes follow. Session length varies by compound, from several hours with psilocybin or LSD to just minutes with fast-acting agents like 5-MeO-DMT. Neuroplastogens may rely on repeated dosing, but their optimal schedules are still unknown because none have reached late-stage trials. PK/PD readouts remain straightforward: linearity of PK, Cmax, Tmax, AUC, half-life, metabolism, brain penetration, and how these exposures relate to biological signals such as plasma BDNF, EEG markers, early symptom trajectories, or receptor occupancy. The goal is simply to map exposure to effect, without depending on an acute psychedelic state.
The fourth pillar focuses on molecular and cellular plasticity. Psychedelics rapidly increase BDNF expression and TrkB activation and these effects are measurable within hours of dosing. Structural remodeling, including dendritic spine growth, unfolds over a longer and less predictable window, with formation and stabilization representing distinct processes that are not yet well characterized in human cortical tissue. Neuroplastogens aim to produce these same signatures without hallucinogenic signaling, and early data suggest they can induce comparable changes in vitro and in vivo, though human evidence is still limited. The readouts here are clear: BDNF mRNA and protein levels, TrkB phosphorylation, activation of pathways such as mTOR or ERK, expression of synaptic proteins like PSD-95, and measurements of spine density or morphology. These markers indicate whether a compound can produce the structural adaptations associated with lasting therapeutic effects.
The fifth pillar covers behavioral and clinical outcomes. Psychedelics often produce rapid improvements on measures such as MADRS and HAM-A, sometimes within one to three days, though these benefits emerge in supervised settings because of acute psychological and cardiovascular risks. Neuroplastogens have not yet reached late-stage trials, so their clinical timelines are still uncertain. Early data suggest that improvements may build across repeated dosing, but this remains preliminary until longer trials are completed. Beyond depression, demoralization syndrome represents a distinct target construct, particularly in cancer patient populations, where scales capturing meaning, agency, and existential distress such as the Demoralization Scale may outperform MADRS and HAM-A as primary endpoints. The readouts in this pillar are direct and widely accepted: MADRS, HAM-A, CGI-I, symptom trajectories, preclinical assays such as novelty-suppressed feeding or forced-swim immobility, and safety profiles that track liabilities including hERG inhibition, 5-HT2B activation, metabolic effects, and drug-drug interactions.
Taken together, these five pillars provide a structured way to evaluate both psychedelic and non-hallucinogenic approaches while avoiding assumptions about superiority or scalability. Psychedelics generate high-amplitude, short-duration changes in network dynamics and subjective experience, with an acute window that typically lasts several hours before downstream plasticity processes unfold across days. Neuroplastogens aim to produce measurable plasticity and clinical benefit without relying on acute perceptual disruption, though their eventual dosing models and therapeutic timelines remain open questions. These are precisely the trade-offs we will explore in our conversation with Sonia Weiss Pick of WPSS.bio, who must weigh such scientific signals against portfolio construction and capital allocation in real time.
