How long does 3C-P last?

The total duration of 3C-P via oral is 10 hours to 16 hours. Onset typically occurs within 1 hour to 2 hours. Peak effects last 4 hours to 8 hours.

3C-P — SubstanceWiki

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.

How 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(15)

Appetite suppression— A distinct decrease in hunger and desire to eat, ranging from reduced interest in food to complete d...
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...
Dry mouth— A persistent, uncomfortable reduction in saliva production causing the mouth and throat to feel parc...
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...
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...
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 ...

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
APICA	Caution	Cannabis can unpredictably intensify psychedelic effects and increase anxiety
Atropa belladonna	Caution	Unpredictable compounding of hallucinogenic effects with anticholinergic delirium
Benzydamine	Caution	Increases anxiety, cardiovascular stress, and psychological intensity
Bromantane	Caution	Increases anxiety, cardiovascular stress, and psychological intensity
Cannabidiol	Caution	Cannabis can unpredictably intensify psychedelic effects and increase anxiety
Datura	Caution	Unpredictable compounding of hallucinogenic effects with anticholinergic delirium
Dichloropane	Caution	Increases anxiety, cardiovascular stress, and psychological intensity
Diphenhydramine	Caution	Unpredictable compounding of hallucinogenic effects with anticholinergic delirium
Ephedrine	Caution	Increases anxiety, cardiovascular stress, and psychological intensity
Harmala alkaloid	Caution	MAOIs dramatically potentiate psychedelics; drastically reduce dose and exercise extreme caution
Hexedrone	Caution	Increases anxiety, cardiovascular stress, and psychological intensity
Methcathinone	Caution	Increases anxiety, cardiovascular stress, and psychological intensity
Nicotine	Caution	Increases anxiety, cardiovascular stress, and psychological intensity
Oxiracetam	Caution	Increases anxiety, cardiovascular stress, and psychological intensity
Peganum harmala	Caution	MAOIs dramatically potentiate psychedelics; drastically reduce dose and exercise extreme caution
Phenylpiracetam	Caution	Increases anxiety, cardiovascular stress, and psychological intensity
Rhodiola Rosea	Caution	Increases anxiety, cardiovascular stress, and psychological intensity
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
2C-T-21	Low Risk & Synergy	Cross-tolerance exists; effects compound
2C-T-7	Low Risk & Synergy	Cross-tolerance exists; effects compound
3-Cl-PCP	Low Risk & Synergy	Produces unique synergistic effects; often combined
3-HO-PCE	Low Risk & Synergy	Produces unique synergistic effects; often combined
3-HO-PCP	Low Risk & Synergy	Produces unique synergistic effects; often combined
3-MeO-PCE	Low Risk & Synergy	Produces unique synergistic effects; often combined
3-MeO-PCMo	Low Risk & Synergy	Produces unique synergistic effects; often combined
3-MeO-PCP	Low Risk & Synergy	Produces unique synergistic effects; often combined
4-MeO-PCP	Low Risk & Synergy	Produces unique synergistic effects; often combined
Allylescaline	Low Risk & Synergy	Cross-tolerance exists; effects compound
Ayahuasca	Low Risk & Synergy	Cross-tolerance exists; effects compound
Deschloroketamine	Low Risk & Synergy	Produces unique synergistic effects; often combined
DET	Low Risk & Synergy	Cross-tolerance exists; effects compound
Diphenidine	Low Risk & Synergy	Produces unique synergistic effects; often combined
DiPT	Low Risk & Synergy	Cross-tolerance exists; effects compound
DOM	Low Risk & Synergy	Cross-tolerance exists; effects compound
DPT	Low Risk & Synergy	Cross-tolerance exists; effects compound
Efavirenz	Low Risk & Synergy	Cross-tolerance exists; effects compound
Ephenidine	Low Risk & Synergy	Produces unique synergistic effects; often combined
EPT	Low Risk & Synergy	Cross-tolerance exists; effects compound
HXE	Low Risk & Synergy	Produces unique synergistic effects; often combined
Ibogaine	Low Risk & Synergy	Cross-tolerance exists; effects compound
Inhalants	Low Risk & Synergy	Produces unique synergistic effects; often combined
Memantine	Low Risk & Synergy	Produces unique synergistic effects; often combined
MET	Low Risk & Synergy	Cross-tolerance exists; effects compound
Methallylescaline	Low Risk & Synergy	Cross-tolerance exists; effects compound
MiPT	Low Risk & Synergy	Cross-tolerance exists; effects compound
MPT	Low Risk & Synergy	Cross-tolerance exists; effects compound
MXiPr	Low Risk & Synergy	Produces unique synergistic effects; often combined
O-PCE	Low Risk & Synergy	Produces unique synergistic effects; often combined
PCE	Low Risk & Synergy	Produces unique synergistic effects; often combined
Psilocybin Mushrooms	Low Risk & Synergy	Cross-tolerance exists; effects compound
Lorazepam	Low Risk & Decrease	Depressants dull psychedelic effects; benzodiazepines are commonly used as trip-killers

Showing 60 key interactions out of 79 total.

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.

Full	almost immediately after ingestion
Half	3 days
Zero	7 days

3C-P

Dosage

Duration

oral

How It Feels

Subjective Effects

Physical Effects

Physical(15)

Tactile(1)

Cognitive & Perceptual Effects

Visual(16)

Pharmacology

Mechanism of Action

Structural Considerations

Pharmacokinetics

Detection Methods

Urine Detection

Blood and Serum Detection

Standard Drug Panel Inclusion

Confirmatory Methods

Reagent Testing (Harm Reduction)

Interactions

History

Shulgin's Documentation

Research Chemical Status

Legal Status

Harm Reduction

Preparation and Set/Setting

Dose Guidelines

Duration Management

Reagent Testing

Contraindications

Toxicity & Safety

Acute Toxicity

Cardiovascular Burden

Psychological Risk

Redosing Hazard

Addiction Potential

Overdose Information

Tolerance

Cross-tolerances

Legal Status

Experience Reports (2)

Tips (5)

See Also

Similar by Effects

Same Class

References (4)

Frequently Asked Questions

Cognitive(16)

Multi-sensory(1)

Transpersonal(2)