Overview
4-HO-DiPT (4-hydroxy-N,N-diisopropyltryptamine), known as iprocin, is a synthetic psychedelic tryptamine and a structural analog of psilocin in which both N-methyl groups are replaced with isopropyl groups. It was first synthesized by Repke et al. in 1977 as part of a systematic investigation of psilocin analogs and was later explored and documented by Alexander and Ann Shulgin in TiHKAL (Tryptamines I Have Known and Loved) .
4-HO-DiPT is particularly notable for its pronounced auditory distortion effects — a characteristic it shares with its close relative DiPT (N,N-diisopropyltryptamine). Users frequently report alterations in pitch perception, with sounds appearing lower-pitched, along with volume distortion and temporal distortion of auditory rhythms. Shulgin himself remarked that "there is likely no other psychedelic drug that can match this one for speed, intensity, brevity, and dose sensitivity" among orally active compounds .
The compound's rapid onset (often within 15-20 minutes orally), relatively short duration (2-4 hours), and steep dose-response curve distinguish it from most other tryptamine psychedelics. These properties, combined with its unusual auditory effects, make it pharmacologically interesting despite limited formal research .
References
- Repke DB, Ferguson WJ. Psilocin analogs. 1. Synthesis of 3-[2-(dialkylamino)ethyl]- and 3-[2-(cycloalkylamino)ethyl]indol-4-ols. J Heterocyclic Chem. 1977;14:71-74.
- Shulgin A, Shulgin A. TiHKAL: The Continuation. Transform Press, 1997. Entry #17: 4-HO-DiPT.
Safety at a Glance
High Risk- It is strongly recommended that one use harm reduction practices when using this drug.
- HO-not habit-forming, and the desire to use it can actually decrease with regular consumption. Like with most psyched...
- Toxicity: The toxicity and long-term health effects of recreational 4-HO-DiPT use do not seem to have been studied in any scien...
- Overdose risk: Fatal overdose from 4-HO-DiPT alone, at doses within the typical recreational range, is extremely...
If someone is in crisis, call 911 or Poison Control: 1-800-222-1222
Dosage
oral
Duration
oral
Total: 2 hrs – 4 hrsHow It Feels
The onset of 4-HO-DiPT begins with a growing strangeness in the auditory field. Within twenty to forty minutes, sounds begin to acquire an uncanny quality — a slight warping, as though voices and ambient noise are being processed through some invisible filter. A ringing or buzzing may appear at the periphery of hearing, faint but persistent. Simultaneously, a body load builds: a heavy, somewhat queasy pressure in the abdomen, accompanied by vasoconstriction that sends cold tingling into the hands and feet. The overall onset sensation is more disorienting than most tryptamines, precisely because the auditory changes are so unusual and difficult to contextualize.
As the experience matures over the next hour, the auditory effects become pronounced and unmistakable. Pitch shifts are the signature phenomenon: voices drop or rise in tone, sometimes by as much as a full octave, creating a deeply surreal conversational experience. Music becomes almost unrecognizable — familiar melodies warp and stretch, harmonics shift, and the emotional character of sound is fundamentally altered. Rhythmic perception changes too; beats may seem to drag or accelerate independently of their actual tempo. The effect is less like hearing the world with enhanced clarity and more like hearing a parallel version of the world where the rules of acoustics are slightly different. Visually, the effects are present but secondary: mild color enhancement, soft geometric patterning, and a dreamy haze over the visual field.
The peak, reaching full intensity around two hours and lasting two to three hours more, can be a challenging territory. The persistent auditory distortion creates an underlying sense of unreality that permeates the headspace. Thoughts may feel circular or difficult to ground, and communication becomes effortful when voices sound so unfamiliar. The body load at peak can be considerable — nausea, muscle tension, and a general physical discomfort that sits uneasily alongside the perceptual strangeness. For those who can surrender to the experience, however, there is a genuinely fascinating dimension to it: the discovery that so much of how we understand reality is mediated through auditory anchoring, and that disrupting those anchors reshapes consciousness in unexpected ways.
The comedown is slow, spanning three to four hours, with auditory normality returning last. The body gradually relaxes, warmth returns to the extremities, and a tired but clear-headed calm settles in. The experience often leaves a lasting appreciation for the complexity and fragility of human hearing.
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(9)
- Body load— A diffuse, heavy physical discomfort involving tension, pressure, and malaise in the torso and limbs...
- 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...
- Muscle tension— Persistent partial contractions or tightening of muscles that produces uncomfortable stiffness, cram...
- Nausea— An uncomfortable sensation of queasiness and stomach discomfort that may or may not lead to vomiting...
- Pupil dilation— A visible enlargement of the pupil diameter (mydriasis) that can range from subtle widening to drama...
- 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...
- Vasoconstriction— A narrowing of blood vessels throughout the body that produces sensations of cold extremities, tingl...
Cognitive & Perceptual Effects
Visual(17)
- 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...
- Perspective hallucination— A hallucinatory phenomenon in which the observer's visual perspective shifts from the normal first-p...
- 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(14)
- 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...
- Delusion— A delusion is a fixed, false belief that is held with unshakeable certainty and is impervious to con...
- Immersion enhancement— A heightened capacity to become fully absorbed and engrossed in external media such as music, films,...
- Mania— Abnormally elevated mood, energy, and activity with impulsive behavior and grandiosity, associated w...
- 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...
- Panic attack— A panic attack is a discrete episode of acute, overwhelming fear or terror that arises suddenly and ...
- 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 loops— Becoming trapped in a repeating cycle of thoughts, actions, and emotions that loops every few second...
- Time distortion— Subjective perception of time becomes dramatically altered — minutes may feel like hours, or hours p...
Auditory(4)
- Auditory distortion— Auditory distortion is the experience of sounds becoming warped, pitch-shifted, flanged, or otherwis...
- Auditory enhancement— Auditory enhancement is a heightened sensitivity and appreciation of sound in which music, voices, a...
- Auditory hallucination— Auditory hallucination is the perception of sounds that have no external source — hearing music, voi...
- Auditory misinterpretation— Auditory misinterpretation is the brief, spontaneous misidentification of real sounds as entirely di...
Multi-sensory(1)
- Scenarios and plots— Scenarios and plots are the narrative structures that emerge within hallucinatory states — coherent ...
Transpersonal(2)
- Ego death— A profound dissolution of the sense of self in which personal identity, memories, and the boundary b...
- Unity and interconnectedness— A profound sense that identity extends beyond the self to encompass other people, nature, or all of ...
Pharmacology
Pharmacology
Mechanism of Action
4-HO-DiPT acts as an agonist at the serotonin 5-HT2A receptor, consistent with the general pharmacology of the 4-substituted tryptamine class. Activation of 5-HT2A receptors in cortical neurons is the primary mechanism underlying the psychedelic state, and 4-HO-DiPT's effects are expected to be blocked by selective 5-HT2A antagonists such as ketanserin .
Auditory Cortex Effects
The most pharmacologically intriguing aspect of 4-HO-DiPT is its pronounced auditory distortion, a trait shared with DiPT and other diisopropyltryptamines. The prevailing hypothesis is that the bulky diisopropyl substituents on the terminal nitrogen alter the compound's receptor binding profile in a way that preferentially affects auditory cortical processing, possibly through differential agonism at 5-HT2A receptor populations in auditory cortex or through additional activity at non-5-HT2A targets that modulate auditory perception .
This selectivity for auditory distortion remains poorly understood at the molecular level. Functional selectivity (biased agonism) at the 5-HT2A receptor — where different ligands stabilize distinct receptor conformations and activate different intracellular signaling cascades — is one proposed explanation for why structurally similar tryptamines can produce such different perceptual profiles .
Duration and Dose-Response
4-HO-DiPT is notable for its rapid onset and relatively brief duration compared to most oral tryptamines. It also exhibits an unusually steep dose-response curve, with small dosage increments producing disproportionately large changes in effect intensity — a feature that demands caution with dosing .
References
- Fantegrossi WE, et al. Hallucinogen-like effects of N,N-dipropyltryptamine (DPT): possible mediation by serotonin 5-HT1A and 5-HT2A receptors in rodents. Pharmacol Biochem Behav. 2008;88(3):358-365.
- Shulgin A, Shulgin A. TiHKAL: The Continuation. Transform Press, 1997.
Detection Methods
Urine Detection
4-HO-DiPT is not targeted by standard immunoassay-based urine drug screens. Specialized LC-MS/MS methods can detect 4-substituted tryptamine metabolites in urine for approximately 24 to 48 hours after ingestion. The detection window is relatively short compared to many other drug classes due to the rapid hepatic metabolism and renal clearance of tryptamine compounds. Psilocin (4-HO-DMT) is the most commonly targeted analyte in specialized tryptamine panels, and structural analogs may or may not be captured depending on the specific method.
Blood and Serum Detection
Blood detection windows for 4-HO-DiPT are short, typically 4 to 12 hours after oral ingestion. Peak plasma concentrations of the active metabolite occur within 1 to 2 hours. The rapid first-pass metabolism means that parent compound concentrations in blood are often negligible for 4-AcO prodrugs, while 4-HO compounds themselves are measured directly. LC-MS/MS is required for reliable serum detection at the low concentrations involved.
Standard Drug Panel Inclusion
4-HO-DiPT is NOT included on standard 5-panel, 10-panel, or 12-panel drug screens. Tryptamines do not cross-react with immunoassay targets for any of the standard panel analytes (amphetamines, cannabinoids, cocaine metabolites, opiates, PCP, benzodiazepines, or barbiturates). Detection requires a specific request for tryptamine or novel psychoactive substance testing at a reference laboratory. Some extended forensic panels include psilocin, which may capture certain 4-substituted tryptamines, but this coverage is not guaranteed for all structural variants.
Confirmatory Methods
Confirmatory identification of 4-HO-DiPT relies on LC-MS/MS with reference standards specific to the compound or its expected metabolites. GC-MS can also be used following appropriate derivatization. Immunoassay-based methods for psilocybin and psilocin exist but show variable cross-reactivity with structural analogs and are not considered reliable for novel 4-substituted tryptamines. Reference laboratories specializing in novel psychoactive substances offer the most comprehensive detection capabilities.
Reagent Testing (Harm Reduction)
The Ehrlich reagent is the primary harm reduction tool for 4-HO-DiPT. A sample placed on the reagent should produce a purple to violet color change, confirming the presence of an indole ring system characteristic of tryptamines. This reaction is shared with LSD, psilocybin, DMT, and all indole-containing compounds, so it confirms the general class but not the specific identity. The Hofmann reagent provides a confirmatory blue to violet reaction for tryptamines. The Marquis reagent typically shows no reaction or a dark brown discoloration with 4-substituted tryptamines. A positive Ehrlich result significantly reduces the probability that the substance is a dangerous substitute such as an NBOMe compound.
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
The history of 4-HO-DiPT is intertwined with the broader story of psychedelic research, which has oscillated between periods of intense scientific interest and strict prohibition.
Like many psychedelic compounds, 4-HO-DiPT was either synthesized in a laboratory setting or identified as a naturally occurring psychoactive substance through ethnobotanical research. The mid-20th century saw an explosion of interest in psychedelic compounds, with researchers exploring their potential applications in psychotherapy, creativity enhancement, and the study of consciousness.
The political and cultural backlash of the late 1960s and early 1970s led to the criminalization of most psychedelic substances, effectively halting legitimate research for decades. The resurgence of psychedelic research beginning in the 2000s — often called the "psychedelic renaissance" — has renewed scientific interest in this class of compounds, with clinical trials exploring applications in treatment-resistant depression, PTSD, end-of-life anxiety, and addiction.
4-HO-DiPT exists within this broader pharmacological and cultural context, with its specific history shaped by its date of discovery, legal status, availability, and unique pharmacological profile.
Harm Reduction
It is strongly recommended that one use harm reduction practices when using this drug.
4-HO-not habit-forming, and the desire to use it can actually decrease with regular consumption. Like with most psychedelics, it is most often thought to be self-regulating.
Tolerance to the effects of 4-HO-almost immediately after ingestion. After that,37 days to be back at baseline (in the absence of further consumption). 4-HO-DiPT presents cross-tolerance with Cross-all psychedelics, meaning that after the consumption of 4-HO-DiPT all psychedelics will have a reduced effect.
Due to its relative obscurity, the possession and sale of 4-HO-DiPT is unscheduled in most countries.
- Germany: 4-HO-DiPT is controlled under the NpSG (New Psychoactive Substances Act) as of July 18, 2019. Production and import with the aim to place it on the market, administration to another person, placing it on the market and trading is punishable. Possession is illegal but not punishable. The legislator considers it possible that orders of 4-HO-DiPT are punishable as an incitement to place it on the market.
- Sweden: 4-HO-DiPT is classified as a "health hazard" under the act "Lagen om förbud mot vissa hälsofarliga varor" (translated to the "Act on the Prohibition of Certain Goods Dangerous to Health") as of March 1, 2005 in their regulation SFS 2005:26, making it illegal to sell or possess.
- Switzerland: 4-HO-DiPT is not controlled under Buchstabe A, B, C and D. It could be considered legal.
- United Kingdom: 4-HO-DiPT is a Class A drug in the United Kingdom as a result of the tryptamine catch-all clause.
- United States: 4-HO-DiPT is unscheduled in the United States. It may be considered an analogue of psilocin (4-HO-DMT), a Schedule I drug
Toxicity & Safety
The toxicity and long-term health effects of recreational 4-HO-DiPT use do not seem to have been studied in any scientific context and the exact toxic dose is unknown. This is because 4-HO-DiPT is a research chemical with very little history of human usage.
Anecdotal reports from those who have tried 4-HO-DiPT suggests that there are no negative health effects attributed to simply trying it by itself at low to moderate doses and using it very sparingly (but nothing can be completely guaranteed). Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.
It is strongly recommended that one use harm reduction practices when using this drug.
Tolerance and addiction potential
4-HO-DiPT is not habit-forming, and the desire to use it can actually decrease with regular consumption. Like with most psychedelics, it is most often thought to be self-regulating.
Tolerance to the effects of 4-HO-DiPT is built almost immediately after ingestion. After that, it takes about 3 days for the tolerance to be reduced to half and 7 days to be back at baseline (in the absence of further consumption). 4-HO-DiPT presents cross-tolerance with all psychedelics, meaning that after the consumption of 4-HO-DiPT all psychedelics will have a reduced effect.
Dangerous interactions
Warning: Many psychoactive substances that are reasonably safe to use on their own can suddenly become dangerous and even life-threatening when combined with certain other substances. The following list provides some known dangerous interactions (although it is not guaranteed to include all of them).
Always conduct independent research (e.g. Google, DuckDuckGo, PubMed) to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.
Lithium - Lithium is commonly prescribed for the treatment of bipolar disorder. There is a large body of anecdotal evidence that suggests taking it with psychedelics significantly increases the risk of psychosis and seizures. As a result, this combination is strictly discouraged.
Cannabis - Cannabis may have an unexpectedly strong and unpredictable synergy with the effects of 4-HO-DiPT. Caution is advised with this combination as it can significantly increase the risk of adverse psychological reactions like anxiety, paranoia, panic attacks, and psychosis. Users are advised to start off with only a fraction of their normal cannabis dose and take long breaks between hits to avoid unintentional overdose.
Stimulants - Stimulants like amphetamine, cocaine or methylphenidate affect many parts of the brain and alter dopaminergic function. This combination can increase the risk of anxiety, paranoia, panic attacks, and thought loops. This interaction may also result in an elevated risk of mania and psychosis.
Tramadol - Tramadol is well-documented to lower the seizure threshold and psychedelics may act to trigger seizures in susceptible individuals.
Addiction Potential
not habit-forming
Overdose Information
Fatal overdose from 4-HO-DiPT 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
Due to its relative obscurity, the possession and sale of 4-HO-DiPT is unscheduled in most countries.
Germany: 4-HO-DiPT is controlled under the NpSG (New Psychoactive Substances Act) as of July 18, 2019. Production and import with the aim to place it on the market, administration to another person, placing it on the market and trading is punishable. Possession is illegal but not punishable. The legislator considers it possible that orders of 4-HO-DiPT are punishable as an incitement to place it on the market.
Sweden: 4-HO-DiPT is classified as a "health hazard" under the act "Lagen om förbud mot vissa hälsofarliga varor" (translated to the "Act on the Prohibition of Certain Goods Dangerous to Health") as of March 1, 2005 in their regulation SFS 2005:26, making it illegal to sell or possess.
Switzerland: 4-HO-DiPT is not controlled under Buchstabe A, B, C and D. It could be considered legal.
United Kingdom: 4-HO-DiPT is a Class A drug in the United Kingdom as a result of the tryptamine catch-all clause.
United States: 4-HO-DiPT is unscheduled in the United States. It may be considered an analogue of psilocin (4-HO-DMT), a Schedule I drug under the Controlled Substances Act. As such, the sale for human consumption or the use for illicit non-medical or industrial intents and purposes could be prosecuted as crimes under the Federal Analogue Act.
Florida: 4-HO-DiPT is a Schedule I controlled substance in the state of Florida, making it illegal to buy, sell, or possess.
Responsible use
Research chemical
Psychedelic
Tryptamine
DiPT
4-HO-DiPT (Wikipedia)
4-HO-DiPT (Erowid Vault)
4-HO-DiPT (TiHKAL / Isomer Design)
Community
The Big & Dandy 4-HO-DiPT Thread (Bluelight)
Experience Reports (1)
Tips (8)
4-HO-DiPT has an unusually narrow dose range. The difference between a light and overwhelming experience can be as little as 5mg. Use a precise milligram scale and start at the low end (15-20mg) regardless of your experience with other tryptamines.
Despite literature claiming 4-HO-DiPT lasts only 3-4 hours, some users report effects lasting 6+ hours. Individual metabolism varies significantly with this compound. Do not plan time-sensitive activities assuming a short trip.
4-HO-DiPT is uniquely known for its strong auditory effects among tryptamines. Music may sound distorted, pitch-shifted, or completely transformed. This can be either fascinating or disturbing depending on your mindset. Have familiar, calming music ready.
Integration is just as important as the experience itself. After using 4-HO-DiPT, take time to journal, reflect, or discuss the experience. Insights from psychedelic states can be powerful but need conscious effort to apply to daily life.
Set and setting are paramount with 4-HO-DiPT. Choose a familiar, comfortable environment where you feel safe. Have trusted company or a trip sitter, especially for your first experience. Avoid stressful locations or social obligations.
Always test 4-HO-DiPT with an Ehrlich reagent before use. A positive reaction (purple/pink color change) confirms the presence of an indole/lysergamide compound. No reaction could indicate a dangerous substitute like an NBOMe.
Community Discussions (1)
See Also
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
- 4-HO-DiPT - TripSit Factsheet
TripSit factsheet for 4-HO-DiPT
tripsit - 4-HO-DiPT - Wikipedia
Wikipedia article on 4-HO-DiPT
wikipedia