2C-B (4-bromo-2,5-dimethoxyphenethylamine) is a synthetic psychedelic phenethylamine first synthesized by Alexander Shulgin in 1974 and published in his seminal book PiHKAL (Phenethylamines I Have Known and Loved) in 1991. Among Shulgin's hundreds of synthesized compounds, 2C-B has emerged as one of the most widely used psychedelic phenethylamines in the world, prized for its unique dose-dependent character: at lower doses (10–15 mg), it produces an empathogenic, sensory-enhancing experience with mild visual effects; at higher doses (20–30 mg), it transitions into a fully psychedelic state with profound visual complexity, altered thinking, and perceptual intensity comparable to MDMA combined with a visual psychedelic. This dose-responsiveness and its relatively shorter duration (4–6 hours) compared to LSD have made 2C-B popular among experienced psychonauts who value predictability and manageability.
2C-B's subjective profile occupies a distinctive niche between MDMA's empathogenic warmth and LSD's cognitive depth. Users describe vivid and colorful visual effects that are more "fluid" and "liquid" than those of LSD or psilocybin, with a body experience that includes tactile enhancement, warmth, and heightened physical sensation. Community experience consistently notes that 2C-B produces less introspective cognitive heaviness than LSD — it tends toward playfulness, sensory immersion, and aesthetic appreciation rather than philosophical excavation. This character has made it a consistent favorite in festival and social contexts. Reddit users frequently compare it favorably to MDMA for its reduced neurotoxicity concern and longer duration, and to LSD for its more grounded, "body-present" quality.
As a phenethylamine, 2C-B shares chemical ancestry with mescaline but is not directly related to amphetamines despite the class name. Its primary mechanism involves 5-HT2A receptor agonism (like all classical psychedelics) combined with significant activity at dopaminergic and adrenergic pathways, contributing to its stimulant component and heightened sensory tone. Importantly, 2C-B does not appear to produce the serotonin neurotoxicity risk associated with MDMA, and it lacks LSD's binding at dopamine D2 receptors. Tolerance and cross-tolerance with other serotonergic psychedelics occurs.
2C-B is classified as Schedule I in the United States and under similar prohibitive frameworks in most countries, though its legal status varies and it occupies grey areas in some jurisdictions. A persistent concern in the contemporary market is adulteration — pills and powders sold as 2C-B may contain other substances, including more dangerous novel phenethylamines or NBOMe compounds. Reagent testing before use is essential.
