3C-P (3-carbon proscaline; chemically 2-(4-propoxy-3,5-dimethoxyphenyl)-1-aminopropane) is a synthetic psychedelic in the substituted amphetamine/substituted phenethylamine class, documented by Alexander Shulgin in PiHKAL as Compound #8. It is the 3-carbon homolog of proscaline (2C-P extended by one methylene unit in the aminoalkyl chain) and shares the propoxy ether group at the 4-position of the phenyl ring.
3C-P is distinguished from other members of the 3C-x and 2C-x families by its extraordinarily long duration — reported at 12–18 hours or longer in some accounts — and substantial potency at doses as low as 15–25 mg. This extended duration dramatically amplifies both the therapeutic potential and the hazard profile compared to shorter-acting psychedelics. The intensity is consistently described as high: profound visual and cognitive effects, extended plateau phases, and a prolonged resolution period that can bleed into the following day. For most users, a dose of 3C-P represents a full-day-plus commitment — not a substance to approach without thorough preparation and a completely clear schedule.
Safety at a Glance
High Risk- Preparation and Set/Setting
- C-P demands more thorough preparation than shorter-acting psychedelics. Do not use unless you have:
- Toxicity: Acute Toxicity Pharmacological toxicity from 3C-P alone at typical doses is not documented to be life-threatening in ...
- Overdose risk: Fatal overdose from 3C-P alone, at doses within the typical recreational range, is extremely unli...
If someone is in crisis, call 911 or Poison Control: 1-800-222-1222
Duration
oral
Total: 10 hrs – 16 hrsHow It Feels
The onset of 3C-P is a study in patience. Two hours may pass before the first effects become convincingly apparent -- a gradual sharpening of mental focus, a mild stimulant warmth in the chest, and a slowly building awareness that color and contrast have been subtly enhanced. The extended come-up tests the resolve of even experienced psychonauts, and the temptation to supplement the dose during this interminable waiting period must be firmly resisted. This substance unfolds on its own schedule, and that schedule is long.
Between the two and four hour marks, the experience finally reaches its full expression, revealing a powerful hybrid state that combines significant psychedelic depth with relentless stimulant drive. Visual effects are strong and detailed -- crisp, angular geometric patterns with a technological quality, rendered in vivid, saturated colors. Surfaces shimmer and develop complex recursive detail. The visual component is more intense than 3C-E and sustains at a high level for an extraordinary duration. The stimulant energy is formidable: heart rate elevated, pupils dilated, appetite completely suppressed, and a ceaseless mental drive that keeps thoughts churning at high speed.
The headspace is intense and multifaceted. There is a powerful analytical quality, as though the mind has been equipped with additional processing power and is eager to deploy it. Introspective depth is significant -- the substance can push exploration of personal psychological material with a persistent, probing intensity. At the same time, the stimulant component maintains a sharpness of focus that prevents the dissolution and surrender that characterizes tryptamine psychedelics. Emotional amplification is moderate, and the experience can oscillate between intellectual excitement and more vulnerable, emotionally exposed territory. Music is dramatically enhanced and can serve as a powerful anchor for the experience. The body load is significant: persistent stimulation, jaw tension, vasoconstriction, and occasional waves of nausea.
The duration is the defining feature of 3C-P. Total effects can extend sixteen to twenty-four hours, making it one of the longest-acting psychedelics available. The peak alone may last eight to twelve hours. The descent is agonizingly slow, with stimulant effects persisting long past the point where the psychedelic content has become exhausting rather than illuminating. Sleep is impossible for the duration. The aftermath requires serious recovery -- deep fatigue, appetite recovery, and often a full day or more of rest. 3C-P demands commitment. It is not a substance to be taken casually; it is an expedition that requires provisioning, endurance, and the acceptance that one's schedule belongs to the molecule until it decides to release its grip.
Subjective Effects
The effects listed below are based on the Subjective Effect Index (SEI), an open research literature based on anecdotal reports and personal analyses. They should be viewed with a healthy degree of skepticism. These effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects.
Physical Effects
Physical(21)
- Appetite suppression— A distinct decrease in hunger and desire to eat, ranging from reduced interest in food to complete d...
- Bodily control enhancement— Bodily control enhancement is the subjective feeling of improved physical precision, coordination, a...
- Body load— A diffuse, heavy physical discomfort involving tension, pressure, and malaise in the torso and limbs...
- Dehydration— A state of insufficient bodily hydration manifesting as persistent thirst, dry mouth, and physical d...
- Diarrhea— Diarrhea is the occurrence of frequent, loose, or watery bowel movements as a side effect of certain...
- Difficulty urinating— Difficulty urinating, also known as urinary retention, is the experience of being unable to easily p...
- Dry mouth— A persistent, uncomfortable reduction in saliva production causing the mouth and throat to feel parc...
- Increased blood pressure— Increased blood pressure (hypertension) is an elevation of arterial pressure above the normal 120/80...
- Increased heart rate— A noticeable acceleration of heartbeat that can range from a subtle awareness of one's pulse to a fo...
- Increased libido— A marked enhancement of sexual desire, arousal, and sensitivity to erotic stimuli that can range fro...
- Increased salivation— Increased salivation (hypersalivation or sialorrhea) is the excessive production of saliva beyond wh...
- Laughter fits— Spontaneous, uncontrollable, and often prolonged episodes of intense laughter that erupt without any...
- Nausea— An uncomfortable sensation of queasiness and stomach discomfort that may or may not lead to vomiting...
- Physical euphoria— An intensely pleasurable bodily sensation that can manifest as waves of warmth, tingling electricity...
- Pupil dilation— A visible enlargement of the pupil diameter (mydriasis) that can range from subtle widening to drama...
- Sedation— A state of deep physical and mental calming that manifests as a progressive desire to remain still, ...
- Seizure— Uncontrolled brain electrical activity causing convulsions and loss of consciousness -- a life-threa...
- Stimulation— A state of heightened physical and mental energy characterized by increased wakefulness, elevated mo...
- Teeth grinding— An involuntary clenching and rhythmic grinding of the jaw muscles, known clinically as bruxism, that...
- Temperature regulation disruption— Impaired thermoregulation causing unpredictable fluctuations between feeling hot and cold, with risk...
- Vasoconstriction— A narrowing of blood vessels throughout the body that produces sensations of cold extremities, tingl...
Tactile(1)
- Tactile enhancement— The sense of touch becomes dramatically heightened, making physical contact feel intensely pleasurab...
Cognitive & Perceptual Effects
Visual(16)
- After images— A visual phenomenon in which a faint, ghostly imprint of a previously viewed image persists in the v...
- Brightness alteration— Perceived increase or decrease in environmental brightness beyond actual illumination levels, common...
- Colour enhancement— An intensification of the brightness, vividness, and saturation of colors in the external environmen...
- Colour shifting— The visual experience of colors on objects and surfaces cycling through continuous, fluid transforma...
- Depth perception distortions— Alterations in how the distance of objects within the visual field is perceived, causing layers of s...
- Diffraction— The experience of seeing rainbow-like spectrums of color and prismatic halos embedded within bright ...
- Drifting— The visual experience of perceiving stationary objects, textures, and surfaces as appearing to flow,...
- Geometry— The experience of perceiving complex, ever-shifting geometric patterns superimposed over the visual ...
- Internal hallucination— Vivid, detailed visual experiences perceived within an imagined mental landscape that can only be se...
- Pattern recognition enhancement— An increased ability and tendency to perceive meaningful patterns, faces, and images within ambiguou...
- Perspective distortions— Distortion of perceived depth, distance, and size of real objects, making things appear closer, furt...
- Settings, sceneries, and landscapes— The perceived environment in which hallucinatory experiences take place, ranging from recognizable l...
- Symmetrical texture repetition— Textures appear to mirror and tessellate across surfaces in intricate, self-similar symmetrical patt...
- Tracers— Moving objects leave visible trails of varying length and opacity behind them, similar to long-expos...
- Transformations— Objects and scenery undergo perceived visual metamorphosis, smoothly shapeshifting into other recogn...
- Visual acuity enhancement— Vision becomes sharper and more defined than normal, as though a slightly blurry lens has been broug...
Cognitive(17)
- Analysis enhancement— A perceived improvement in one's ability to logically deconstruct concepts, recognize patterns, and ...
- Anxiety— Intense feelings of apprehension, worry, and dread that can range from a subtle background unease to...
- Cognitive euphoria— A cognitive and emotional state of intense well-being, elation, happiness, and joy that manifests as...
- Conceptual thinking— A shift in the nature of thought from verbal, linear sentence structures to intuitive, non-linguisti...
- Confusion— An impairment of abstract thinking marked by a persistent inability to grasp or comprehend concepts ...
- Immersion enhancement— A heightened capacity to become fully absorbed and engrossed in external media such as music, films,...
- Increased sense of humor— A general amplification of one's sensitivity to finding things humorous and amusing, often causing p...
- Introspection— An enhanced state of self-reflective awareness in which one feels drawn to examine their own thought...
- Memory suppression— A dose-dependent inhibition of one's ability to access and utilize short-term and long-term memory, ...
- Novelty enhancement— A feeling of increased fascination, awe, and childlike wonder attributed to everyday concepts, objec...
- Paranoia— Irrational suspicion and belief that others are watching, plotting against, or intending harm toward...
- Personal bias suppression— A decrease in the personal, cultural, and cognitive biases through which one normally filters their ...
- Psychosis— Psychosis is a serious psychiatric state involving a fundamental break from consensus reality — char...
- Thought acceleration— The experience of thoughts occurring at a dramatically increased rate, as if the mind has been shift...
- Thought connectivity— A state in which disparate thoughts, concepts, and ideas become fluidly and spontaneously interconne...
- Time distortion— Subjective perception of time becomes dramatically altered — minutes may feel like hours, or hours p...
- Wakefulness— An increased ability to stay awake and alert without the desire to sleep. Distinct from stimulation ...
Multi-sensory(2)
- Scenarios and plots— Scenarios and plots are the narrative structures that emerge within hallucinatory states — coherent ...
- Synaesthesia— Stimulation of one sense triggers involuntary experiences in another — seeing sounds as colors, tast...
Transpersonal(2)
- Existential self-realization— A sudden, visceral realization of the profound significance and improbability of one's own existence...
- Unity and interconnectedness— A profound sense that identity extends beyond the self to encompass other people, nature, or all of ...
Pharmacology
Mechanism of Action
3C-P acts as a 5-HT2A receptor partial agonist, the canonical mechanism of classical psychedelics. Like mescaline and 2C-P, the propoxy group at the 4-position contributes to the compound's potency and duration relative to methoxy or ethoxy substituted analogs. The longer the alkoxy chain at the 4-position, generally the greater the lipophilicity, receptor residence time, and CNS penetration — contributing to the extended duration.
Structural Considerations
The 3-carbon (aminopropyl) chain versus the 2-carbon (aminoethyl) chain of the 2C-x series produces further increases in duration and shifts in metabolic profile. The combination of a propoxy 4-position ether and a 3-carbon chain creates one of the longest-acting oral phenethylamine psychedelics in the pharmacological literature.
Pharmacokinetics
3C-P is orally active at 15–40 mg. Onset is characteristically slow — 90–150 minutes — reflecting the extended absorption and metabolic activation time of highly lipophilic phenethylamine analogs. Peak effects may not be reached until 3–6 hours after ingestion. Total duration is typically 12–18 hours, with residual stimulation possible for an additional 4–6 hours. The risk of premature redosing — believing the initial dose was insufficient — is particularly acute given this extended onset.
Detection Methods
Urine Detection
3C-P is not specifically targeted by standard immunoassay-based urine drug panels. However, because 2C-x phenethylamines share structural features with amphetamines, they may trigger false positives on amphetamine immunoassays in some cases. The likelihood of cross-reactivity depends on the specific immunoassay manufacturer and the antibody selectivity used. Urine detection windows for 3C-P are estimated at 24 to 72 hours following ingestion when analyzed by LC-MS/MS methods, though limited pharmacokinetic data exists for many 2C-x compounds.
Blood and Serum Detection
Blood detection windows for 3C-P are approximately 6 to 24 hours after oral administration. Peak plasma concentrations typically occur 1 to 3 hours post-ingestion. The relatively short half-lives of most 2C-x phenethylamines mean that blood testing must be performed promptly to capture detectable concentrations. LC-MS/MS is the only reliable method for quantitative blood analysis.
Standard Drug Panel Inclusion
3C-P is NOT specifically included on standard 5-panel, 10-panel, or 12-panel drug screens. The primary concern for individuals undergoing routine screening is the potential for amphetamine cross-reactivity on immunoassay-based panels. If a presumptive positive for amphetamines occurs, confirmatory testing by GC-MS or LC-MS/MS would not confirm amphetamine and the result would be reported as negative unless the laboratory specifically tests for 2C-x compounds. Most routine laboratories do not include 2C-x phenethylamines in their confirmatory panels.
Confirmatory Methods
Definitive identification of 3C-P requires LC-MS/MS or GC-MS with appropriate reference standards. Some forensic toxicology laboratories include 2C-x phenethylamines in their extended novel psychoactive substance panels. Immunoassay cross-reactivity alone is insufficient for confirmation and would be resolved by standard confirmatory procedures. Quantitative analysis typically requires specific method development as these compounds are not part of routine clinical chemistry workflows.
Reagent Testing (Harm Reduction)
For harm reduction identification, the Marquis reagent is a primary screening tool for 3C-P. The Marquis reagent produces a variable green to brown reaction with 3C-P. As a 3-carbon chain phenethylamine, cross-reactivity with amphetamine immunoassays is possible. Due to 3C-P's high potency and long duration, correct identification is especially important. The Mecke reagent may provide additional color reactions that help differentiate between specific 2C-x variants. The Ehrlich reagent shows no reaction with 2C-x phenethylamines, which can help distinguish them from tryptamines and lysergamides. The Mandelin reagent may produce green to brown reactions depending on the specific compound. Using multiple reagents in combination provides the most reliable field identification, though reagent testing cannot determine purity or dosage.
Interactions
| Substance | Status | Note |
|---|---|---|
| 3-FMA | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| 4-MMC | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| 8-Chlorotheophylline | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| Adrafinil | Caution | Increases anxiety, cardiovascular stress, and psychological intensity |
| Anandamide | Caution | Cannabis can unpredictably intensify psychedelic effects and increase anxiety |
| Cannabis | Uncertain | — |
| 1,3-Butanediol | Low Risk & Synergy | Cross-tolerance exists; effects compound |
| 25E-NBOH | Low Risk & Synergy | Cross-tolerance exists; effects compound |
| 2C-T | Low Risk & Synergy | Cross-tolerance exists; effects compound |
| 2C-T-2 | Low Risk & Synergy | Cross-tolerance exists; effects compound |
History
Shulgin's Documentation
3C-P appears as Compound #8 in Shulgin's PiHKAL (1991), with evaluations in the 15–25 mg range. Shulgin's notes emphasize the long duration and profound effects, describing it as a compound requiring respect and careful preparation. The PiHKAL documentation represents the primary scientific reference for 3C-P, as it does for most obscure phenethylamine psychedelics.
Research Chemical Status
3C-P has remained a relatively obscure research chemical with limited distribution compared to 2C-P or mescaline. The extremely long duration is frequently cited as a barrier to casual use, contributing to its self-selected user base of experienced psychedelic explorers.
Legal Status
3C-P is not explicitly scheduled in most jurisdictions but falls under analogue control in the United States, UK, and many European nations. It exists in the same legal grey zone as most PiHKAL compounds that have not achieved sufficient prevalence to attract specific scheduling.
Harm Reduction
Preparation and Set/Setting
3C-P demands more thorough preparation than shorter-acting psychedelics. Do not use unless you have:
- A completely clear schedule for the following 24 hours
- A trusted, sober trip sitter present or on call for the full duration
- A comfortable, controllable private environment
- Prior experience with psychedelics — 3C-P is inappropriate for first or early experiences
Dose Guidelines
- Threshold: 10–15 mg |Common: 15–30 mg |Strong: 30–45 mg
- Start extremely conservatively — 15 mg or lower for an initial experience. The long duration means consequences of an unexpectedly strong dose last many hours.
- Wait at minimum 2 hours before any supplemental dose. Preferably 3 hours. The slow onset is not an indicator of insufficient dosing.
Duration Management
Prepare for a 14–20 hour commitment. Have food, water, comfortable spaces, and engaging but not demanding sensory material (nature, calm music, art) available. Avoid commitments the following morning.
Reagent Testing
Use Mecke (blue-green for methoxylated phenethylamines),Marquis (limited reaction for pure phenethylamine psychedelics — absence of orange-black rules out amphetamine adulterants), andSimon's to characterize structure.
Contraindications
- MAOIs — absolute contraindication
- Personal or family history of psychosis, schizophrenia, or bipolar I
- Cardiovascular disease, hypertension
- Obligations requiring cognitive function within 24 hours of dosing
Toxicity & Safety
Acute Toxicity
Pharmacological toxicity from 3C-P alone at typical doses is not documented to be life-threatening in otherwise healthy individuals, but the extended duration substantially amplifies hazard exposure. A bad psychological experience lasting 14–18 hours is a qualitatively different clinical problem than one lasting 6–8 hours, and behavioral consequences of impaired judgment accumulate over the prolonged duration.
Cardiovascular Burden
Alpha-adrenergic stimulation produces tachycardia, hypertension, and vasoconstriction for the full duration of the experience — an unusually prolonged cardiovascular burden compared to other psychedelics. This is particularly concerning for individuals with cardiac or vascular risk factors.
Psychological Risk
The combination of high potency, long duration, and complex psychedelic character means that difficult experiences are unusually taxing. The 12–18 hour duration removes the option for the experience to "just end soon" — a common coping thought that helps navigate shorter psychedelic experiences. Psychological preparation for the possibility of difficulty is especially important.
Redosing Hazard
The long onset creates significant redosing risk: users who dose orally and feel nothing at 60–90 minutes may supplement, only to find both doses active simultaneously as the experience peaks. This is one of the most common routes to unexpectedly overwhelming experiences with long-acting phenethylamines.
Addiction Potential
not habit-forming
Overdose Information
Fatal overdose from 3C-P alone, at doses within the typical recreational range, is extremely unlikely based on the available evidence for classical psychedelics. The therapeutic index for most psychedelics is very wide.
However, psychological emergencies can occur and require appropriate response:
- Severe anxiety, panic, or psychotic episodes
- Dangerous behavior due to impaired reality testing
- Self-harm in the context of a distressing experience
Emergency management: If someone is experiencing a severe adverse reaction, move them to a calm, quiet environment. Speak reassuringly. Do not restrain unless there is immediate danger. Benzodiazepines (if available and the person is conscious and able to swallow) can reduce acute anxiety. If psychotic symptoms, self-harm risk, or medical distress is present, seek emergency medical attention.
Medical attention: Seek help immediately for seizures, extremely elevated body temperature, signs of serotonin syndrome (agitation, tremor, diarrhea, rapid heart rate), or if the substance consumed is uncertain.
Tolerance
| Full | almost immediately after ingestion |
| Half | 3 days |
| Zero | 7 days |
Cross-tolerances
Legal Status
United Kingdom: It is illegal to produce, supply, or import this drug under the Psychoactive Substance Act, which came into effect on May 26th, 2016.
United States: 3C-P is technically not scheduled in the United States, but could be considered an analog of mescaline and may, therefore, be considered a Schedule I drug under the Federal Analogue Act.
Japan: 3C-P is a controlled substance in Japan effective February 28th, 2018.
Responsible use
Psychoactive substance index
Mescaline
Psychedelics
3C-P (Wikipedia)
3C-P (Isomer Design)
Experience Reports (1)
Tips (5)
Stay hydrated while using 3C-P. Stimulants increase heart rate and body temperature while suppressing thirst signals. Sip water regularly, roughly 250-500ml per hour, more if dancing or in hot environments.
Test 3C-P with appropriate reagent kits and fentanyl test strips. Stimulant supplies have increasingly been found contaminated with fentanyl, which has caused a surge in overdose deaths among stimulant users.
Have a landing plan for the 3C-P comedown. Prepare food, melatonin or magnesium, and a comfortable environment in advance. Avoid using depressants to manage the comedown as this creates polydrug dependency patterns.
Monitor your heart rate and blood pressure when using 3C-P. Sustained elevated cardiovascular stress causes cumulative damage. If you experience chest pain, irregular heartbeat, or numbness in extremities, seek medical attention.
Weigh your dose of 3C-P with a milligram scale. Street stimulants vary wildly in purity and potency. What looks like a normal amount could be significantly stronger than expected, especially with a new batch.
See Also
Same Class
References (4)
- Psilocybin produces substantial and sustained decreases in depression and anxiety — Griffiths et al. Journal of Psychopharmacology (2016)paper
- Neural correlates of the LSD experience revealed by multimodal neuroimaging — Carhart-Harris et al. PNAS (2016)paper
- 3C-P - TripSit Factsheet
TripSit factsheet for 3C-P
tripsit - 3C-P - Wikipedia
Wikipedia article on 3C-P
wikipedia