3,4-CTMP
threo-3,4-dichloromethylphenidate
Viewing r1 — May 12, 2026 — CURRENT
Back to HistoryInteractions, related substances, and reports reflect the current entry and are not shown for historical revisions.
3,4-CTMP (3,4-dichloromethylphenidate) is a synthetic stimulant of the phenidate class. It is a halogenated structural analog of methylphenidate, approximately 7- to 32-fold more potent at DAT inhibition.[1] 3,4-CTMP is a dopamine–norepinephrine reuptake inhibitor, producing its effects by blocking the clearance of these neurotransmitters from the synapse.[2]
Psychedex is in open beta. We are still fine-tuning the generation and review process. Please double-check sources.
Synthesized in the mid-1990s at Georgia Institute of Technology as part of a search for potential cocaine antagonists,[1] 3,4-CTMP remained an obscure research compound for nearly two decades. It appeared on UK research chemical markets in 2013[3] and was subsequently scheduled in multiple jurisdictions. It holds no approved medical use and circulates in small quantities among research chemical users.
Subjective effects include sustained stimulation, cognitive enhancement, appetite suppression, and prominent vasoconstriction. The experience is defined by a tension between potency and latency — a deceptively slow oral onset masks considerable pharmacological force,[4] producing a noradrenergic body state of cold extremities and persistent heart rate awareness. Compulsive redosing urge, prolonged insomnia, and cognitive dysphoria during offset are characteristic unsought effects.
Among phenidate analogs studied, 3,4-CTMP demonstrates the greatest dopamine efflux potency, suggesting elevated addictive liability.[3] The primary acute risk is dose stacking during the prolonged onset window; chronic use raises theoretical concern for cardiac valve damage through serotonin₂B receptor activation.[2] The evidence base is almost entirely preclinical — no controlled human studies, pharmacokinetic parameters, or dependence data have been published.
History[edit]
Discovery
3,4-CTMP was synthesized by Howard M. Deutsch at the Georgia Institute of Technology as part of a medicinal chemistry program investigating potential cocaine antagonists.[1] The working hypothesis held that a long-acting DAT inhibitor with slow onset might attenuate cocaine craving without producing rapid reinforcement.[4] The 3,4-dichloro structural analog emerged as among the most potent in a series of ring-substituted methylphenidate analogs, inhibiting dopamine uptake up to 32-fold more potently than the parent compound.
Market emergence and scheduling
The compound appeared on UK research chemical markets in 2013, sold as powder and pellets through online vendors.[3] It arrived alongside a wave of phenidate novel psychoactive substances — ethylphenidate, methylnaphthidate, isopropylphenidate, and propylphenidate — that collectively represented a new generation of methylphenidate-derived stimulants entering European drug markets.
Regulatory response
Sweden classified 3,4-CTMP as a hazardous substance in November 2014. The UK Advisory Council on the Misuse of Drugs recommended a Temporary Class Drug Order covering five phenidate compounds in March 2015,[5] with permanent Class B scheduling following in May 2017.[6] China, Germany, and Canada each scheduled the compound between 2015 and 2016.
The abbreviation "3,4-CTMP" is technically imprecise — the compound is more accurately designated 3,4-DCMP (3,4-dichloromethylphenidate). "CTMP" refers specifically to the threo diastereomer, the form sold on research chemical markets, while "DCMP" encompasses all diastereomers. Both terms appear interchangeably in user communities and the literature.
Chemistry[edit]
Structural class
3,4-CTMP belongs to the substituted phenidate class — esters of ritalinic acid bearing modifications to the aromatic ring, ester chain, or piperidine nitrogen. The parent compound, methylphenidate, is the methyl ester of threo-ritalinic acid. 3,4-CTMP retains the methyl ester but introduces two chlorine atoms at the 3- and 4-positions of the phenyl ring, producing a 3,4-dichlorophenyl moiety.
This dichlorination is the key structural modification. It dramatically increases transporter binding potency and confers resistance to aromatic ring oxidation — a primary metabolic pathway for methylphenidate — accounting for 3,4-CTMP's substantially prolonged duration of action.
Molecular properties
| Molecular formula | C₁₄H₁₇Cl₂NO₂ |
| Molecular weight | 302.2 g/mol |
Stereochemistry
Like methylphenidate, 3,4-CTMP possesses two chirality centers — at C-2 of the piperidine ring and at the α-carbon of the phenylacetate moiety — yielding four stereoisomers arranged as two diastereomeric pairs (threo and erythro). The pharmacologically active form sold on the research chemical market is the threo racemic mixture.[7]
By analogy with methylphenidate, the d-threo enantiomer is expected to carry the majority of pharmacological activity, though enantioselective binding data specific to 3,4-CTMP have not been published.
Physical properties
No published characterization of the free base or hydrochloride salt exists. Melting point, solubility, and stability data have not been reported. The compound has been sold commercially as a white-to-off-white powder and in pressed pellet form.
Pharmacology[edit]
Mechanism of action
3,4-CTMP blocks the reuptake of dopamine and norepinephrine by inhibiting their respective transporters (DAT and NET), increasing the availability of both neurotransmitters in the synapse.[2] Unlike amphetamine-class stimulants, it does not cause transporters to reverse direction and flood the synapse with monoamines — it simply prevents their clearance.
The 3,4-dichloro substitution produces three consequential changes relative to methylphenidate: a roughly 12-fold increase in dopamine transporter potency, a 76-fold increase in norepinephrine transporter potency, and the acquisition of meaningful SERT affinity — a property absent in the parent compound.[2] Despite this serotonergic activity, the compound remains predominantly catecholaminergic.
3,4-CTMP also activates serotonin₂B serotonin receptors.[2] This is clinically significant: chronic activation of 5-HT₂B receptors is the established mechanism behind the cardiac valve damage that led to fenfluramine's withdrawal from the market. Whether 3,4-CTMP reaches the occupancy threshold for this effect in typical human use is unknown.
Pharmacokinetics
No human pharmacokinetic data exist for 3,4-CTMP. No values for peak blood concentration, plasma half-life, or bioavailability have been published in any species.
Metabolic analysis using rat urine and human liver fractions identified 7 phase I metabolites, with hydrolysis to a ritalinic acid structural analog as the primary pathway.[8] By structural analogy with methylphenidate, which is primarily cleared by carboxylesterases rather than cytochrome P450 enzymes, 3,4-CTMP likely follows the same route — though this remains an inference.inferred
The 3,4-dichloro substitution increases resistance to aromatic ring oxidation, accounting for the compound's prolonged duration (6–18 hours versus 4–6 hours for methylphenidate). Community reports describe oral onset of 2–4 hours — significantly slower than methylphenidate — with total duration of 10–18 hours and aftereffects persisting up to 24 hours.[9]
Neuroscience[edit]
Where it acts
3,4-CTMP's DAT blockade concentrates its effects in the brain's reward and arousal circuits. In the nucleus accumbens, it produces approximately a 6-fold increase in dopamine release at concentrations where methylphenidate has minimal effect[3] — the neurochemical basis for its reinforcing properties and euphoria.
Norepinephrine transporter blockade in arousal circuits drives wakefulness, attentional sharpening, and the pronounced sympathetic activation (vasoconstriction, elevated heart rate, pupil dilation) that users consistently report.[2] At low to moderate doses, increased catecholamine tone in the prefrontal cortex enhances working memory and sustained attention. The shift from "functional" to "overstimulating" at higher doses is consistent with the well-characterized inverted-U dose–response for prefrontal dopamine.
Why it matters
The mesolimbic dopamine system mediates wanting — incentive salience — rather than liking per se. 3,4-CTMP's potent dopamine transporter blockade in the nucleus accumbens strongly amplifies wanting, which may explain user reports of compulsive redosing even when hedonic effects are modest.
Repeated exposure to dopamine reuptake inhibitors can produce behavioral sensitization — an increasing motivational response — even as tolerance develops to subjective effects. This dual process, sensitization of wanting alongside tolerance to liking, is thought to underlie escalating stimulant use patterns.
Key unknowns include whether 3,4-CTMP exhibits slow dissociation from the dopamine transporter, which would contribute to its long duration independent of metabolic resistance.[10] The threshold at which its serotonin₂B activation becomes relevant for cardiac valve damage has not been established.
Subjective Effects[edit]
3,4-CTMP produces a sustained, focused stimulation dominated by its noradrenergic signature — cold extremities, body-state alertness, and prominent vasoconstriction reported more consistently than with most stimulants in its class. At lower doses the experience is narrowly functional; at higher doses, euphoria emerges alongside increasing cardiovascular adverse effects and a mounting compulsive compulsive redosing urge. Set, setting, and individual cardiovascular health significantly modulate the experience.
Relative to methylphenidate, 3,4-CTMP is qualitatively similar but quantitatively more intense at every dimension — stronger stimulation, longer duration, more pronounced vasoconstriction, and a more insistent redosing urge. Compared to amphetamine, it is less euphoric and more peripheral in its side-effect profile, with a substantially longer tail.
Effect Grid
Clear stimulant effects at 4–6 mg oral. Pronounced focus enhancement, motivation enhancement, thought acceleration, and thought organization. Wakefulness is strong and sustained. Mild cognitive euphoria is possible, with time alteration (time passing quickly during engaged tasks).
Appetite suppression is prominent. Vasoconstriction becomes noticeable — cold fingers, elevated heart rate awareness, possible headache. Stimulation is unmistakable. Bruxism and dehydration sensation may appear. Pupil dilation is visible.
Duration is 8–14 hours. Insomnia is guaranteed for 8+ hours post-dose. Compulsive redosing urge may emerge at this tier. Do not dose after midday if sleep is needed that night.
Modeled from the effect's dose-dependence curve — not per-substance measurements.
Sound sensitivity · Touch enhancement · Auditory enhancement · Tinnitus · Touch suppression · Visual acuity suppression
Touch suppression · Visual acuity suppression
Appetite suppression · Dry mouth · Insomnia · Heart rate perception changes · Physical fatigue · Restlessness · Dehydration sensation · Body high · Excessive sweating · Muscle tension · Respiratory stimulation · Temperature dysregulation · Bruxism · Headache · Sexual arousal suppression · Bodily lightness · Nausea · Tingling / electric sensations · Motor control enhancement · Dizziness · Spontaneous body sensations · Constipation · Increased urination · Sexual arousal enhancement · Tactile euphoria · Trembling · Involuntary body movements · Vomiting · Brain zaps
Heart rate perception changes · Physical fatigue · Restlessness · Dehydration sensation · Body high · Excessive sweating · Muscle tension · Respiratory stimulation · Bruxism · Headache · Sexual arousal suppression · Bodily lightness · Nausea · Tingling / electric sensations · Motor control enhancement · Dizziness · Spontaneous body sensations · Constipation · Increased urination · Sexual arousal enhancement · Tactile euphoria · Trembling · Involuntary body movements · Vomiting · Brain zaps
Analysis enhancement · Motivation enhancement · Thought organization · Cognitive fatigue · Immersion enhancement · Information processing enhancement · Pattern recognition enhancement · Memory enhancement · Cognitive dysphoria · Aesthetic enhancement · Cognitive flexibility · Conceptual thinking · Multiple thought streams · Novelty enhancement · Creativity enhancement · Language enhancement · Motivation suppression · Thought connectivity · Thought loops · Humor enhancement · Thought deceleration
Immersion enhancement · Information processing enhancement · Pattern recognition enhancement · Memory enhancement · Cognitive dysphoria · Aesthetic enhancement · Cognitive flexibility · Conceptual thinking · Multiple thought streams · Novelty enhancement · Creativity enhancement · Language enhancement · Motivation suppression · Thought connectivity · Thought loops · Humor enhancement · Thought deceleration
Emotional suppression · Anhedonia · Dysphoria · Emotional lability
Ego inflation · Disinhibition · Sociability enhancement
Timeline
Near-silent. No perceptible effects for most users during this 2–4 hour window. This is the critical danger period for premature redosing — do not take additional doses during onset.
Gradual emergence of stimulation, focus, and alertness. Peripheral effects begin — vasoconstriction, slight heart rate elevation, cool extremities. Transition from silent to active is gentle, not abrupt.
Full stimulant effects — focus enhancement, motivation, wakefulness, appetite suppression. Dose-dependent euphoria. Pronounced vasoconstriction and cardiovascular activation.
Gradual decline in central stimulation. Residual wakefulness persists. Vasoconstriction fading.
Residual insomnia, physical fatigue, anhedonia, and low mood. Duration is highly variable — some users report aftereffects persisting up to 24 hours.
⚠ Do not drive or operate heavy machinery for at least 18 hours after oral administration, or until stimulant effects and associated fatigue have fully resolved.
Safety[edit]
- Acute toxicity
- Moderate
- Chronic toxicity
- Moderate
- Withdrawal
- Mild
- Tolerance buildup
- moderate
- Tolerance reset
- 14 days
- Physical
- Low
- Psychological
- High
- Compulsive redosing
- High
- Dose escalation
- Moderate
- Cross-tol.
- methylphenidate · ethylphenidate · cocaine
Toxicity
No lethal dose data exist for 3,4-CTMP in any species, and no human toxicity threshold has been established through controlled study. No published case reports of fatalities or hospitalizations specific to 3,4-CTMP were identified in adverse events surveillance covering 2017–2020.[11] The absence of case reports may reflect low prevalence of use rather than low intrinsic toxicity.
Cardiovascular risk
The compound's 76-fold increase in NET potency over methylphenidate[2] predicts pronounced sympathomimetic cardiovascular stress. Expected acute effects include elevated blood pressure, rapid heart rate, and irregular heart rhythm. Overheating is an additional risk, particularly during physical exertion or in warm environments. Stimulant-induced lowering of the seizure threshold is consistent with the class mechanism.
Cardiac valve risk
3,4-CTMP activates serotonin₂B serotonin receptors,[2] a mechanism associated with heart valve damage upon chronic activation — the same pathway that led to fenfluramine's market withdrawal. No heart imaging or cardiac pathology data from 3,4-CTMP users have been published. This risk is theoretical but pharmacologically grounded.safety citation needed
Serotonin toxicity potential
The compound's combined SERT inhibition and 5-HT₂B activation create theoretical serotonin syndrome risk when combined with other serotonergic compounds. No cases of serotonin syndrome involving 3,4-CTMP have been published.safety citation needed
Psychological risks
No controlled data on psychiatric adverse effects exist. User reports indicate dose-dependent anxiety and paranoia at higher ranges, consistent with excessive catecholaminergic stimulation. Compulsive redosing urge is frequently reported as a prominent feature, reflecting the compound's potent DAT inhibition.
Cognitive dysphoria during the comedown — irritability, low mood, and anhedonia — reflects dopamine depletion following sustained reuptake inhibitor. Insomnia is a major concern given the 6–18 hour duration, and extended binges carry risk of delusions and agitation consistent with stimulant psychosis.
Tolerance and dependence
No published tolerance or dependence studies exist for 3,4-CTMP. Tolerance is expected to develop through dopamine downregulation with repeated exposure. Cross-tolerance with Methylphenidate, cocaine, and other dopamine reuptake inhibitors is expected.inferred
Davidson et al. found that 3,4-CTMP produced the greatest nucleus accumbens dopamine enhancement among phenidate analogs tested, concluding it "might be most addictive".[3] The slow onset partially mitigates this prediction — rapid-onset compounds produce stronger conditioned reinforcement[1] — but potent dopamine transporter inhibition and user-reported compulsive redosing suggest meaningful abuse liability.
Physical withdrawal has not been characterized. By class analogy, cessation after chronic use would be expected to produce fatigue, excessive sleep, depressed mood, appetite enhancement, and physical sluggishness.inferred
Drug interactions
No published drug interaction studies specific to 3,4-CTMP exist. All interaction assessments are pharmacologically inferred from the compound's mechanism of action.
Tramadol: Both compounds lower seizure threshold, and combined use creates unpredictable cardiovascular stress. Tramadol's serotonin reuptake inhibition adds serotonin toxicity risk when combined with 3,4-CTMP's serotonin transporter activity.safety citation needed
MDMA: Dual risk of serotonin toxicity from combined serotonin-active compounds and additive cardiovascular strain from combined sympathomimetic stimulation.safety citation needed
MAOIs: Absolute contraindication for all catecholaminergic stimulants. Combined dopamine/norepinephrine reuptake inhibition with monoamine oxidase inhibition risks dangerous blood pressure crisis.safety citation needed
Alcohol: Expected to mask alcohol's sedating effects while maintaining stimulant cardiovascular load, increasing risk of alcohol overconsumption and cardiovascular events.
Other serotonergic compounds: SSRIs, SNRIs, and serotonin releasers carry theoretical serotonin toxicity risk given 3,4-CTMP's serotonin transporter inhibition and 5-HT₂B activation.
Contraindications
No substance-specific contraindication data have been published. The following are inferred from 3,4-CTMP's pharmacological profile.inferred
Absolute:
- Pre-existing cardiovascular disease — elevated blood pressure, coronary artery disease, irregular heart rhythm, or structural heart defects
- Concurrent MAOI use — risk of dangerous blood pressure crisis
- Seizure disorders — stimulants lower seizure threshold
- Existing heart valve disease or pulmonary arterial hypertension — 5-HT₂B activation may worsen these conditions
Relative:
- Anxiety disorders — catecholaminergic stimulation may worsen anxiety
- History of stimulant dependence — elevated relapse risk given potent dopamine transporter activity
- Liver impairment — may prolong effects if metabolism depends on hepatic enzymes
- Concurrent serotonergic medication — increased serotonin toxicity risk
- Pregnancy and lactation — no safety data
Harm Reduction[edit]
Forms & Identification
3,4-CTMP has circulated primarily as a white-to-off-white powder and in pressed pellets. No published analytical characterization of street samples exists, meaning purity and composition data are limited. Given the compound's extreme potency relative to other phenidate stimulants, accurate dosing requires a milligram-precision scale — volumetric errors that would be negligible with less potent substances carry real risk here.
Reagent testing can help distinguish 3,4-CTMP from other substance classes but cannot confirm identity or purity. Quantitative analysis through drug checking services provides the only reliable confirmation of what a sample contains.
Guidelines
- Test every batch with reagent kits and, where possible, a quantitative analysis service
- Use a milligram-precision scale — never estimate doses by eye
- Start at the lowest reported threshold dose and wait a full 4 hours before considering any additional dose
- Do not redose during the onset window — premature redosing is the primary cause of adverse experiences with this compound
- Stay hydrated but avoid excessive water intake
- Avoid physical exertion, hot environments, and stimulating settings that amplify cardiovascular stress
- Plan for the full duration — ensure access to a comfortable space for 12–18 hours
- Have a trusted person aware of your use and timeline
- Avoid combining with other stimulants, serotonergic compounds, or cardiovascular stressors
Set & Setting
The prolonged onset (2–4 hours orally) is the single most important factor to plan around. The temptation to redose during this window — before the first dose has taken effect — is the primary acute risk with 3,4-CTMP. Choose a calm, controlled environment for first use, and ensure the setting supports a potentially 12–18 hour commitment.
Cardiovascular health is a precondition. The compound's pronounced noradrenergic effects place sustained stress on the heart and blood vessels. Anyone with undiagnosed or unmanaged heart conditions faces elevated risk.
Aftercare & integration. The extended duration and noradrenergic load of 3,4-CTMP make post-experience recovery a priority. Sleep is the most important intervention — the compound's long tail can disrupt sleep for 24 hours or more, and sleep deprivation compounds cognitive and mood effects.
Eat nutrient-dense food as appetite returns. Hydrate steadily. Avoid caffeine or other stimulants for at least 24 hours after effects subside. Expect low mood, irritability, and reduced motivation for 1–3 days as dopamine systems normalize — this is a predictable neurochemical consequence, not a sign of permanent change.
Recovery & Support
3,4-CTMP's potent dopamine activity and user-reported compulsive redosing urge suggest meaningful dependence potential. Patterns to watch for include escalating doses, inability to discard remaining supply, using to manage the comedown from previous use, and interference with sleep, work, or relationships.
If use has become difficult to control, professional support is available through stimulant-specific treatment programs, SMART Recovery, or consultation with an addiction specialist. Online harm reduction communities can provide peer support and practical guidance for tapering or cessation.
Recovery resources, crisis lines, and support pathways → View all
Emergency Response
Recognizing an emergency: chest pain, severe headache, seizure, loss of consciousness, confusion, or body temperature hot to the touch through clothing are medical emergencies — not discomfort to wait out. Sustained heart rate above 150 bpm at rest, vision changes, or inability to speak coherently also warrant immediate help.
Immediate steps:
- Call emergency services immediately
- Move the person to a cool, quiet environment
- Do not restrain unless there is immediate danger of self-harm
- Monitor breathing and consciousness continuously
- Do not induce vomiting
What to tell the dispatcher: Name the substance (3,4-CTMP or 3,4-dichloromethylphenidate), estimated dose, time of ingestion, and current symptoms. Good Samaritan laws in many jurisdictions protect people who call for help during a drug emergency.
Legal Status[edit]
3,4-CTMP has been scheduled or controlled in multiple jurisdictions following its appearance on research chemical markets in 2013. No jurisdiction has approved the compound for medical use. In countries without explicit scheduling, structural analog legislation may apply given its structural derivation from methylphenidate.
| Jurisdiction | Classification | Key provisions |
|---|---|---|
| United Kingdom | Class B, Schedule 1 (Misuse of Drugs Act 1971) | Permanent scheduling from 31 May 2017;[6] preceded by Temporary Class Drug Order from 10 April 2015[12] |
| Sweden | Controlled (hazardous substance) | Classified 10 November 2014 |
| China | Controlled | Scheduled October 2015 |
| Germany | Controlled (NpSG) | Under New Psychoactive Substances Act from 26 November 2016 |
| Canada | CDSA Schedule III | Scheduled November 2016 |
| United States | Not explicitly scheduled | Likely subject to Federal Analogue Act (21 U.S.C. § 813) as a structural analog of Schedule II methylphenidate when intended for human consumptioncitation needed |
| Australia | Not confirmed | Possibly subject to analog provisions; no explicit scheduling confirmedcitation needed |
The UK scheduling history illustrates the regulatory approach to phenidate analogs as a class. The ACMD recommendation of March 2015 covered five methylphenidate-related compounds simultaneously — reflecting concern about the proliferating phenidate analog market rather than substance-specific risk assessment.[5]
references
- [1] ^abcdDeutsch H, Shi Q, Gruszecka-Kowalik E, Schweri M (1996) Synthesis and Pharmacology of Potential Cocaine Antagonists. 2. Structure-Activity Relationship Studies of Aromatic Ring-Substituted Methylphenidate Analogs — Journal of Medicinal Chemistry doi:10.1021/jm950697c
- [2]
- [3]
- [4] ^abFroimowitz M, Taboada R, Poulos ZJ, Rainone DJ, Imler GH, Gardner EL, Kelley CJ (2023) Chiral Resolution of the Enantiomers of the Slow-Onset Dopamine Reuptake Inhibitor CTDP-32476 and Their Activities — ACS Omega doi:10.1021/acsomega.3c02997
- [5]
- [6]