2C-P (2,5-dimethoxy-4-propylphenethylamine)

Overview

2C-P is a synthetic psychedelic of the substituted phenethylamine family and a member of the 2C-x series (2C-B, 2C-I, 2C-E, 2C-T-x, etc.). It is the 4-propyl analogue of the 2C-x family and is notable for an exceptionally long duration — considerably longer than most other 2C compounds. It is one of the more potent and longer-acting members of the series, and has been associated with several serious adverse events when used at higher doses.

IUPAC name: 2-(2,5-dimethoxy-4-propylphenyl)ethanamine
Molecular formula: C₁₃H₂₁NO₂
Molecular weight: ~223.31 g/mol
CAS Number: 178313-47-4 (hydrochloride: 178313-48-5)
Class: Psychedelic phenethylamine (2C-x series); potent 5-HT₂A agonist

History & Origin

2C-P was synthesized and characterized as part of the systematic exploration of phenethylamine structure–activity relationships. It is documented in Alexander Shulgin’s PiHKAL (entry #24), where it is described as producing a long, visually intense experience. It has only a modest presence in the recreational drug literature compared to 2C-B or 2C-I.

Pharmacology

2C-P acts as an agonist at serotonin 5-HT₂A and 5-HT₂C receptors, with the standard phenethylamine pharmacological profile. The longer 4-propyl substituent (relative to methyl, ethyl, or halogen substituents in other 2C-x compounds) appears to extend both duration and intensity.

Receptor binding: Agonist at 5-HT₂A and 5-HT₂C; activity at 5-HT₂B and trace-amine-associated receptors
Active oral dose: ~6–12 mg
Onset: 1–2 hours (oral)
Duration: 10–16 hours (occasionally reported up to ~20 hours)
Routes: Oral (most common); insufflation reported but more painful and riskier

Documented Effects (Shulgin, PiHKAL)

At common doses, 2C-P produces:

Strong visual hallucinations (geometric patterns, color enhancement, trailing phenomena)
Altered time perception
Euphoria and emotional openness
Introspection and cognitive fluidity
Physical stimulation

At higher doses:

Confusion, paranoia, panic
Nausea and significant body load
Difficulty sleeping for extended periods afterward
Reports of vasoconstriction and, in rare cases, severe hypertensive episodes
Several deaths have been associated with 2C-P, often involving high doses, redosing, or combination with other substances

Safety & Harm Considerations

Long duration — at 10–16 hours, mistakes in dosing or setting are difficult to walk back.
Narrow safety margin — the gap between a common psychedelic dose (~10 mg) and doses associated with severe adverse events appears smaller than for many other 2C-x compounds.
Documented fatalities — case reports link 2C-P to deaths from cardiac arrest, hyperthermia, and trauma during dissociative states, particularly at high doses or in combination with other substances.
Vasoconstriction — peripheral vasoconstriction with risk of tissue ischemia reported.
Serotonergic interactions — dangerous with MAOIs, SSRIs, SNRIs, tramadol, and other serotonergic substances (serotonin syndrome risk).
Tolerance — develops rapidly; full cross-tolerance with other 5-HT₂A agonists resets within ~5–7 days.
Misrepresentation risk — has occasionally been sold in place of other 2C compounds or as “synthetic mescaline,” leading users to misjudge dose.