2-CB

2-CB is a psychedelic phenethylamine of the 2C series, primarily visual and somatic, and weakly entactogenic. The plate presents it as a molecule that preserves the self, with low noetic potential: the experience stays sensory and aesthetic rather than dismantling the ego.

Pharmacology

2-CB acts as a partial agonist at serotonergic 5-HT2 receptors, with peak affinity for 5-HT2B (pKi 8.7), then 5-HT2A (8.4) and 5-HT2C. The plate details several functional consequences of this pharmacology:

• 5-HT2A: visual effects and cognitive modulation.
• 5-HT2C: somatic, tactile and sometimes erotic component.
• 5-HT2B: notable atypical point, with a cardiac concern (valvulopathy) in chronic use.
• Near-absent activity at D2, sigma-1 and TAAR1.

This profile would explain the preservation of the self and the absence of the deep empathogenic or mystical quality typical of other substances: 2-CB occupies a specific niche, more visual and sensory than truly transformative.

Effect on brain networks

Imaging data specific to 2-CB remain limited. By extrapolation from the 5-HT2A class, the plate notes a moderate reduction of cortical hierarchy, a moderate increase in brain entropy, and partial disruption of the default mode network (DMN). These effects would be less pronounced than under LSD or psilocybin, and thus comparable in an attenuated way at higher intensity. The narrative is generally preserved: no structural dissolution of the self.

Functional consequences

Subjectively, the plate reports intense geometric visuals, saturated colours, eyes open as well as closed; marked somatic and tactile activation; an emerging erotic dimension at medium to high doses. It underlines social confidence and disinhibition, without MDMA-style empathogenesis, along with fluid thought and relatively preserved metacognition. There is no structural noetic dimension nor the typical ontological dissolution.

Reported subjective effects

Listed are: enriched visual perceptions and mild synesthesia; geometric patterns, symmetries and chromatic saturation; social and tactile connection, bodily disinhibition; mild euphoria, good mood and lightness; relative mental clarity, creativity and fluidity; time dilation and altered perception.

An atypical glitch: fragments of futures

Outside its usual profile (geometric visuals, the subject preserved), 2-CB can, when added to an already-saturated serotonergic system (for example late in an MDMA session), produce a quite different kind of glitch: brief fragments of possible futures. The gesture of reaching for a phone, and for a fraction of a second the image of having dropped it. Neither the ketamine deformation nor the N,N-DMT absolute: a proleptic intrusion, a normally silent risk surfacing.

One possible reading: this is not a vision but a simulation of the predictive model (the forward model) crossing the threshold of consciousness. The brain continuously computes the sensorimotor consequences of an action, failure branch included (what if it falls), then discards that computation below the reportable threshold; here it leaked into percept. It is the antero-active counterpart of the ketamine frames: ketamine makes the update visible, this glitch makes the prediction visible (see Bayesian brain).

Epistemic caution: the raw phenomenology is a brief visual intrusion at the moment the hand reaches out. That it is the predictive machinery made visible, rather than ordinary imagery retrofitted after the fact to a plausible frame, remains an interpretation, seductive but posed by the returning system. Unlike the ketamine frames (recurrence, structure), this is an isolated event.

Duration and tolerance

By the oral route, onset is 30 to 60 minutes, peak 1 to 2 hours, total duration 5 to 7 hours and comedown 1 to 2 hours. Tolerance is relatively fast; cross-tolerance with LSD and psilocybin is mentioned. A spacing of at least one to two weeks is advised, ideally more.

Harm reduction

The plate stresses how strongly dose-dependent 2-CB is: a narrow margin separates the recreational dose from more intense and disorienting levels, and the nasal route is markedly more painful and unpredictable than the oral route. The central safety concern is valvular: the 5-HT2B receptor, for which 2-CB has its highest affinity, is expressed on the heart valves, and its chronic agonism is associated with valvulopathy, hence contraindications (valvulopathy, uncontrolled hypertension, arrhythmia, pregnancy) and the importance of avoiding close-spaced and chronic use. There is also an acute cardiovascular risk, digestive adverse effects and nausea. Tablets or capsules are sometimes overdosed: start low, weigh if possible. Combinations should be considered cautiously, notably the serotonergic risk with other serotonergic agents. Recreational or therapeutic use within an informed, dose-controlled setting is favoured.

Sources

• Alexander Shulgin, synthesis of 2-CB in 1974 and description in PIHKAL.
• Pharmacological literature on phenethylamine 5-HT2A, 5-HT2B and 5-HT2C receptors.
• Work on brain entropy and the default mode network under serotonergic psychedelics (Carhart-Harris and colleagues).
• Harm-reduction resources such as Erowid and TripSit on 2-CB.