DPT

# Research Output: DPT (N,N-Dipropyltryptamine)

**Generation Provenance ID:** b1748dcb-e331-4e91-868c-b585855f5623  
**Research Date:** 2026-04-20  
**Substance:** DPT / N,N-Dipropyltryptamine  
**PSX ID:** PSX-0173

---

## Chemical Identity

**Verified against PubChem CID 6091 and PubChem REST API**

| Property | Value | Source |
|---|---|---|
| PubChem CID | 6091 | PubChem API |
| IUPAC name | N-[2-(1H-indol-3-yl)ethyl]-N-propylpropan-1-amine | PubChem API |
| Canonical SMILES | CCCN(CCC)CCC1=CNC2=CC=CC=C21 | PubChem REST API [Ref 2] |
| InChI | InChI=1S/C16H24N2/c1-3-10-18(11-4-2)12-9-14-13-17-16-8-6-5-7-15(14)16/h5-8,13,17H,3-4,9-12H2,1-2H3 | PubChem REST API |
| InChIKey | BOOQTIHIKDDPRW-UHFFFAOYSA-N | PubChem API |
| Molecular formula | C₁₆H₂₄N₂ | PubChem API (confirmed) |
| Molecular weight | 244.37 g/mol | PubChem API (confirmed) |
| CAS (free base) | 61-52-9 | Web sources [Ref 36] |
| CAS (HCl salt) | 16382-06-2 | Web sources |
| Melting point | 178–179°C (HCl salt) | TiHKAL [Ref 34] |
| XLogP | 4.3 | PubChem REST API |
| H-bond donors | 1 (indole NH) | PubChem REST API |
| H-bond acceptors | 1 | PubChem REST API |
| Density | ~1.0 g/cm³ | Commercial data [Ref 36] |
| Physical form | Crystalline HCl salt (white solid) or free base (oily liquid) | CFSRE monograph [Ref 35] |

**Notes:**
- The brief's seed data did not include SMILES, InChIKey, PubChem CID, molecular formula, or molecular weight — all have now been verified.
- The IUPAC name given in the brief (N-[2-(1H-indol-3-yl)ethyl]-N-propylpropan-1-amine) is correct and matches PubChem.
- DPT has no stereocenters; it is achiral. No active isomers to consider.
- DPT has not been found to occur endogenously in humans; it is purely synthetic [Ref 36].

---

## Pharmacology

### Primary Receptor Targets

**5-HT2A receptor (primary psychedelic target):**
- Ki = 152 nM (pKi = 6.82 ± 0.116) determined by radioligand competition [Ref 31]
- EC50 = 445 nM (pEC50 = 6.35 ± 0.12) for G-protein coupling (TRUPATH Gα/βγ biosensors) [Ref 31]
- Full agonist activity [Ref 31]
- 5-HT2A mediates the hallucinogenic discriminative stimulus effects; selective 5-HT2A antagonist MDL100907 (M100907) produces functionally insurmountable antagonism of DPT's head-twitch response (HTR) in mice and drug discrimination effects in rats and primates (Fantegrossi et al. 2008 [Ref 3]; Li et al. 2007 [Ref 4]; Li et al. 2009 [Ref 8])
- Schild analysis in rhesus monkeys: pA₂ = 8.50 for MDL100907 vs. DPT — quantitative confirmation of 5-HT2A as primary mediator of discriminative stimulus (Li et al. 2009 [Ref 8])

**5-HT1A receptor (modulatory):**
- Ki = 1640 nM (pKi = 5.78 ± 0.05) [Ref 31]
- EC50 = 2400 nM (pEC50 = 5.61 ± 0.06); **partial agonist, 52% intrinsic activity** [Ref 31]
- IC50 = 0.1 µmol/L at cloned human 5-HT1A (Thiagaraj et al. 2005 [Ref 5]); competitive interaction with [³H]8-OH-DPAT; characterized as **moderate-affinity partial agonist** that activates Gᵢ alone but blocks full 5-HT agonist response
- Thermodynamic analysis shows entropy-driven binding to human 5-HT1A receptor (Hall et al. 2010 [Ref 19])
- WAY-100635 (5-HT1A antagonist) produces surmountable rightward shift of DPT's HTR dose–effect curve in mice — consistent with 5-HT1A partial agonism [Ref 3]
- In rats, DPT at 5-HT2A–blocked conditions unmasked 5-HT1A agonist activity (flat body posture, lower-lip retraction) attenuated by WAY-100635 [Ref 4]

**5-HT1B receptor:**
- Ki = 8081 nM (pKi = 5.09 ± 0.03) [Ref 31]
- EC50 = 1710 nM (pEC50 = 5.77 ± 0.13); partial agonist, 85% intrinsic activity [Ref 31]
- Not considered a major psychedelic target at typical doses

### Serotonin Transporter (SERT)

- DPT inhibits [³H]5-HT uptake at SERT with **KI = 0.594 ± 0.12 µM** (human platelets) [Ref 6]
- High binding-to-uptake ratio indicates DPT is a **transporter substrate, not an uptake blocker** — behaves as a releasing agent/substrate at SERT, not an inhibitor like SSRIs [Ref 6]
- DPT inhibits monoamine reuptake (DA, 5-HT, NE) in rat brain synaptosomes but has minimal effects on monoamine release — consistent with substrate rather than amphetamine-like releasing behavior (Nagai et al. 2007 [Ref 15])

### VMAT2 (Vesicle Monoamine Transporter 2)

- KI for VMAT2 = 19 ± 2.3 µM (Sf9 cells expressing rat VMAT2) [Ref 6]
- VMAT2 substrate behavior suggests DPT may accumulate inside neurons at intracellular vesicles, potentially reaching concentrations sufficient for sigma-1 receptor activation [Ref 6]

### Sigma-1 Receptor

- Cozzi et al. 2009 [Ref 6] hypothesize that DPT's SERT/VMAT2 substrate behavior allows neuronal accumulation sufficient to activate sigma-1 receptors intracellularly
- Tyagi et al. 2023 [Ref 31] tested the selective sigma-1 antagonist NE-100 and found it **did not block DPT's anticonvulsant effects** in FXS mice — the identity of the anticonvulsant mechanism remains unknown

### G-Protein Activation (GTPγS assay)

- DPT stimulates G-protein binding (GTPγS incorporation) in rat brain cortical membranes (Nonaka et al. 2007 [Ref 14])
- Rank order of tryptamine potency: 5-MeO-DMT > 5-MeO-DALT > 5-MeO-AMT ≥ 5-MeO-MIPT > 5-MeO-DIPT > DPT ≥ AMT — DPT is among the lower-potency members [Ref 14]

### NIMH-PDSP Broader Receptor Profile

- Ray (2010) [Ref 2] reported DPT's receptor affinity profile across 51 sites from the NIMH-PDSP. Primary interactions are at serotonin receptors; specific Ki values beyond 5-HT2A and 5-HT1A are not extracted from the abstract but the paper represents the most comprehensive profiling available
- **⚠️ FLAG:** Specific Ki values at DA, adrenergic, histamine, and other receptor families from NIMH-PDSP data were not confirmed via the full paper's supplementary tables (full PDF unavailable through API access). The generation agent should note this gap.

### Summary of Mechanism of Action

DPT is a mixed serotonergic agent with the following hierarchy:
1. **5-HT2A full agonist** (primary psychedelic mechanism, insurmountable by MDL100907 in animal models)
2. **5-HT1A partial agonist** (modulatory; agonism masked at typical doses by dominant 5-HT2A activity)
3. **SERT substrate** (transporter-based serotonin release mechanism; KI ~0.6 µM)
4. **VMAT2 substrate** (intracellular vesicular accumulation)
5. **Unknown anticonvulsant mechanism** independent of serotonin and sigma-1 receptors [Ref 31]

The functional result is intermediate between DMT (purely receptor-mediated) and MDMA (predominantly transporter-mediated) — classifying DPT as a **mixed-action psychedelic** [Ref 13].

### Pharmacokinetics

**⚠️ MAJOR GAP:** No published human pharmacokinetic studies for DPT exist. The following statements are class-level inferences:

- **Oral bioavailability:** Likely metabolized by MAO-A on first pass (by analogy with DMT). The relative oral activity of DPT vs. DMT suggests greater MAO resistance due to the bulkier N,N-dipropyl substitution compared to N,N-dimethyl. Human doses of 100–250 mg orally are reported (TiHKAL [Ref 34]), compared to ~30–60 mg IM/IV, suggesting significant first-pass effect.
- **Metabolism:** Presumed MAO-A substrate (class-level inference from tryptamine analogy); no published CYP enzyme data for DPT specifically. N-dealkylation of propyl groups is the expected primary metabolic pathway.
- **Duration:** Oral effects last 2–4 hours; smoked 20–30 minutes; insufflated 3–5 hours per clinical/community data. Longer duration than DMT consistent with reduced MAO susceptibility and/or greater lipophilicity (XLogP 4.3 vs. DMT ~2.0).
- **Blood-brain barrier:** Moderately lipophilic (XLogP 4.3), suggesting good CNS penetration.

**⚠️ FLAG:** No published T½, Tmax, or absolute bioavailability data for any route of administration.

---

## History

### Synthesis and Discovery

DPT was first synthesized in the early 1950s as part of a systematic campaign to explore N,N-dialkyl tryptamine analogs. The Speeter & Anthony 1954 paper [Ref 33] — a classic tryptamine analog synthesis — is identified as an early reference (cannot be programmatically verified; pre-digital literature). Animal (canine) testing confirmed pharmacological activity in 1954 [Ref 36].

Human psychedelic properties were confirmed in the 1960s through experimental trials. Thiagaraj et al. 2005 [Ref 5] describe DPT as "a synthetic indolealkylamine first characterized in the 1960s." DPT was encountered as a novel designer drug as early as 1968.

### Clinical Research History (1970s)

DPT was investigated as an adjunct to psychotherapy in the 1970s, primarily at the Maryland Psychiatric Research Center (MPRC) by Stanislav Grof, Richard Soskin, William Richards, and Albert Kurland:

**Soskin, Grof, Richards (1973):** "Low doses of Dipropyltryptamine in psychotherapy" — *Archives of General Psychiatry* [Ref 23]. First published clinical study. Low-dose DPT protocol in psychotherapy.

**Grof, Soskin, Richards, Kurland (1973):** "DPT as an adjunct in psychotherapy of alcoholics" — *International Pharmacopsychiatry* [Ref 24]. Controlled study in 103 male adult alcoholic patients. Protocol: low doses of 15–45 mg (1–2 hours, 1–5 sessions) combined with a single full-dose session of 75–265 mg (4–6 hours). Therapist-rated outcomes showed significant enhancement in memory recall, emotional expressiveness, self-exploration depth, and psychodynamic resolution.

**Soskin (1975):** "Dipropyltryptamine in psychotherapy" — *Current Psychiatric Therapies* [Ref 22]. Follow-up clinical report.

**Richards, Rhead, Grof, Goodman, Di Leo, Rush (1980):** "DPT as an Adjunct in Brief Psychotherapy with Cancer Patients" — *OMEGA: Journal of Death and Dying* [Ref 25]. Pilot project with 30 cancer patients experiencing psychological distress. Protocol: ~12 hours conventional verbal therapy + single DPT session of 75–227.5 mg. The "peak experience" — involving profound altered consciousness — was achieved and associated with positive psychological outcomes.

This DPT trial (N=30) is one of the 11 clinical trials included in Reiche et al.'s 2018 systematic review [Ref 9] of serotonergic hallucinogens for terminal illness anxiety/depression.

### Religious Use

The Temple of the True Inner Light, a New York City offshoot of the Native American Church, was founded in 1980 by Alan Birnbaum. DPT is their primary sacramental substance — the Eucharist of their practice. Members believe DPT and other entheogens are physical manifestations of God. Sessions are conducted semi-privately in the temple with Biblical text recordings [Ref 28].

### Regulatory and Market History

- No DEA scheduling of DPT (as of 2025–2026); it remains federally unscheduled in the US
- The DEA proposed scheduling of several tryptamines in January 2022 but withdrew the proposal in July 2022
- DPT has appeared as an NPS (novel psychoactive substance) on research chemical markets; the CFSRE first identified it in their laboratory in March 2025 [Ref 35]

---

## Subjective Effects

No controlled human studies have systematically characterized DPT's subjective effects using validated scales. The following is drawn from human clinical reports (Richards et al. 1980 [Ref 25]; Grof et al. 1973 [Ref 24]) and validated by preclinical evidence.

### Documented Effects in Clinical Settings

- **Profoundly positive feelings and altered consciousness** — the "peak experience" was the desired therapeutic endpoint, achieved with 75–227.5 mg orally or IM [Ref 25]
- **Enhanced memory recall** and deepened emotional expressiveness [Ref 24]
- **Self-exploration** and psychodynamic resolution [Ref 24]
- **Visual hallucinations** — "bright bursts of light," tunnel-like visions, intense visual phenomena (TiHKAL [Ref 34])
- Clinical case report (fatal case, Neukamm et al. 2024 [Ref 1]): Onset of visual hallucinations within 10–15 minutes of insufflation, followed by apathy, then abdominal pain, collapse, seizure, and vomiting over 2 hours

### Effects from Preclinical Models (Rodent/Primate)

DPT produces:
- **Head-twitch response (HTR)** in mice — a validated 5-HT2A–mediated hallucinogen correlate — with a **biphasic dose–effect curve** (Fantegrossi et al. 2008 [Ref 3])
- **Full substitution for LSD and psilocybin discriminative stimuli** in rats [Ref 3]
- **Full-to-partial substitution for MDMA** discriminative stimulus; more potent as R(−)-MDMA cue than S(+)-MDMA cue (Murnane et al. 2009 [Ref 13])
- **>95% DOM-lever responding** at 3.2 mg/kg in DOM-trained rats [Ref 4]
- Flat body posture (5-HT1A–mediated postural effects) in rats [Ref 4]

### Duration Data

| Route | Onset | Peak | Total | After-effects | Source |
|---|---|---|---|---|---|
| Oral | 20–60 min | Not specified | 2–4 hours | 2–3 hours | TiHKAL [Ref 34]; clinical data |
| Smoked | Rapid (~2 min) | — | 20–30 min | — | TiHKAL [Ref 34] |
| Insufflated | 10–15 min | 30–45 min | 3–5 hours | 2–4 hours | Brief seed; case report [Ref 1] |
| IM/IV | 5–15 min | — | 2–4 hours | — | Clinical data [Ref 24, 25] |

**Note on smoked duration:** TiHKAL reports ~20 minutes for the smoked route; the brief's seed data shows "30–90 minutes total (smoked)" — this is not inconsistent if Shulgin's 20 minutes refers to peak intensity. The 30–90 minute range may incorporate the full residual tail. **No contradiction requiring a flag**, but the generation agent should note the range ambiguity.

---

## Safety & Toxicity

### LD50 / Lethal Dose

No LD50 data published for DPT in any species. **⚠️ FLAG: Toxic dose is unknown**, as noted in the brief. No animal lethality studies identified.

### Fatal Case Report

Neukamm et al. 2024 [Ref 1] — the only published fatal case involving DPT:
- 20-year-old male, prior hallucinogen experience
- Insufflated an unknown quantity of DPT in an apartment
- **Timeline:** Visual hallucinations at 10–15 min → apathy at ~30 min → abdominal pain, collapse, seizure, vomiting at ~2 hours post-consumption → death at 21 hours post-consumption despite ECMO
- Cause of death: **aspiration** (not direct pharmacological toxicity); the seizure likely precipitated vomiting and aspiration
- The fatal outcome was likely compounded by delayed emergency response (2.5 hours to hospital)
- Toxicological and morphological findings are presented in the paper; specific blood concentrations not extractable from the abstract

**⚠️ FLAG:** This is the only published fatal case. Death was from aspiration secondary to seizure, not confirmed pharmacological overdose. The causal role of DPT alone vs. other factors cannot be confirmed from the abstract.

### Seizure Risk

DPT exhibits **complex dose-dependent effects on seizure threshold** (Tyagi et al. 2023 [Ref 31]):
- **Anticonvulsant** at 10 mg/kg in Fmr1 KO mice (audiogenic seizures completely prevented)
- **Proconvulsant** at 20+ mg/kg (tonic seizures elicited de novo)
- Previous rat study found DPT proconvulsant at 30 mg/kg
- The fatal case involved a seizure at ~2 hours post-insufflation, suggesting high-dose proconvulsant risk in humans

### Acute Adverse Effects (Clinical Context)

From clinical psychotherapy literature (Grof et al. 1973 [Ref 24]; Richards et al. 1980 [Ref 25]):
- Low rates of serious adverse effects in medically supervised settings
- Physiological effects expected of serotonergic stimulation (cardiovascular, autonomic)
- Specific adverse event rates not extractable from available abstracts

### Organ Toxicity

No specific organ toxicity data published for DPT. By class analogy with other serotonergic tryptamines, concerns include:
- Cardiovascular: Possible blood pressure elevation and tachycardia (class-level inference; 5-HT2A–mediated)
- No hepatotoxicity data available

### Psychological Risks

- Risk of psychosis precipitation in vulnerable individuals — class-level inference
- Anxiety documented in effects taxonomy
- Seizure risk at high doses confirmed in animals [Ref 31]
- HPPD: No DPT-specific data; class-level risk acknowledged [Ref 35]

---

## Harm Reduction

### Route-Specific Risks

- **Insufflation:** Onset is rapid (~10–15 min), with risk of unexpectedly intense response. The fatal case involved insufflation with unknown dose, seizure, and aspiration [Ref 1]. The hard-to-dose nature of insufflation represents a meaningful safety risk.
- **Smoked:** Very rapid onset (~2 min), risk of overwhelming experience before titration
- **Oral:** Slower, more predictable onset; doses 100–250 mg per clinical use [Ref 34]
- **IM/IV:** Requires clinical setting; doses 12–60 mg; used in historical therapeutic studies [Ref 24, 25]

### Drug Testing

DPT is detectable by GC-MS (LOD 5–10 ng/mL in blood) and LC-MS/MS using the Vorce & Sklerov 2004 method [Ref 18]. Standard immunoassay drug screens will **not detect DPT** — there are no commercially available immunoassays for this compound [Ref 20]. The CFSRE confirmed DPT identification only in March 2025 [Ref 35].

Reagent testing: Not specifically characterized for DPT; Ehrlich reagent (reacts with indoles) would be expected to give a positive result, consistent with the indole core.

### Key Contraindications (Literature-Derived)

- **MAO inhibitors:** DPT is a SERT substrate — combination with MAOIs would prevent deamination of released serotonin, dramatically increasing synaptic 5-HT. Life-threatening serotonin syndrome is the expected outcome. **⚠️ Safety-critical; class-based inference — no DPT-specific MAOI interaction studies published.**
- **Serotonergic medications (SSRIs, SNRIs, tricyclics):** Potential additive serotonergic load; serotonin syndrome risk (class inference)
- **Seizure disorders:** Proconvulsant at high doses in animals [Ref 31]; the fatal case involved a seizure [Ref 1]
- **Cardiovascular conditions:** Likely 5-HT2A–mediated cardiovascular stimulation (class inference; no DPT-specific data)
- **Psychiatric history** (personal or family history of psychosis/mania): Standard psychedelic contraindication

---

## Tolerance & Dependence

### Tolerance

Smith et al. 2014 [Ref 7]:
- Daily DPT administration does **not** produce tolerance to the HTR in mice
- This contrasts with phenethylamine-derived hallucinogens (DOI, 2C-T-7) which rapidly develop tolerance
- **Insurmountable cross-tolerance** from DOI to DPT occurs — meaning DOI-tolerant mice show reduced DPT response (DOI cross-tolerance extends to tryptamines)
- The reverse cross-tolerance (DPT → DOI) was not tested
- Authors suggest tryptamine-derived hallucinogens may have reduced tolerance potential for therapeutic applications [Ref 7]

The brief's tolerance field is empty. Based on Smith et al. 2014 [Ref 7], the generation agent can note that DPT appears to have **lower tolerance development potential** than phenethylamine psychedelics for its own effects, though cross-tolerance from phenethylamine class extends to DPT.

### Dependence

- Not habit-forming (confirmed by brief seed; consistent with general psychedelic class evidence)
- No published DPT-specific dependence studies
- Drug discrimination data shows DPT serves as its own discriminative stimulus [Ref 3], confirming reinforcing stimulus properties, but no self-administration data identified
- Brief data ("not habit-forming") is consistent with the general class evidence

### Withdrawal

No published DPT-specific withdrawal data.

---

## Interactions

### Serotonin Syndrome Risk (Most Critical)

DPT combines two serotonergic mechanisms: 5-HT receptor agonism AND SERT substrate behavior (releasing agent). Any drug that also increases synaptic serotonin creates additive/synergistic risk:
- **MAO inhibitors (MAOIs):** Life-threatening interaction predicted; prevents metabolism of DPT-released serotonin. **⚠️ Safety-critical; class-based inference.**
- **SSRIs/SNRIs:** Serotonin syndrome risk (class inference)
- **Other 5-HT2A agonists:** Additive discriminative stimulus effects confirmed in animal models (Li et al. 2010 [Ref 12])

### 5-HT1A Modulation of DPT Effects

- 5-HT1A receptor agonists (e.g., 8-OH-DPAT) show **species-specific modulation** of DPT-like effects: attenuate DOM discriminative stimulus in monkeys but not rats (Li et al. 2010 [Ref 12])
- WAY-100635 (5-HT1A antagonist) produces surmountable shift of DPT's HTR in mice [Ref 3]
- Clinical implication: Drugs with 5-HT1A agonist activity may reduce DPT's hallucinogenic effects; drugs with 5-HT1A antagonist activity may enhance them

### CYP Enzyme Interactions

No published data on CYP inhibition or induction by DPT. **⚠️ FLAG.**

---

## Legal Status

| Jurisdiction | Status | Details | Source |
|---|---|---|---|
| United States (federal) | **Unscheduled** | Not on DEA Schedule I–V; Federal Analogue Act may apply if used for human consumption | Erowid [Ref 27] |
| United States (Florida) | **Schedule I** | Illegal to buy, sell, or possess | Erowid [Ref 27] |
| United States (Maine) | **Schedule X** (equivalent to Schedule I) | Illegal | Erowid [Ref 27] |
| United Kingdom | **Class A** | Controlled under Misuse of Drugs Act; tryptamine clause covers compounds "structurally derived from tryptamine" with alkyl substitutions | Erowid [Ref 27] |
| Portugal | **Table II-A** | Listed alongside MDMA and LSD | Erowid [Ref 27] |
| Belgium | **Restricted** | Most restrictive category (~US Schedule II equivalent) | Erowid [Ref 27] |
| Greece | **Controlled** | Since February 18, 2003 | Erowid [Ref 27] |
| Japan | **Designated Substance** | Under Pharmaceutical Affairs Law; possession and sale prohibited | Erowid [Ref 27] |
| Sweden | **Controlled** | Since January 26, 2016; manufacturing, trade, and possession prohibited | Erowid [Ref 27] |
| New Zealand | **Class C** | As DMT analog under Misuse of Drugs Act | Web sources [Ref 36] |
| Canada | **Unscheduled** | Not specifically listed under Controlled Drugs and Substances Act as of 2025 | Web sources |
| Australia | **Unclear** | Not specifically confirmed as Schedule 9; likely covered as DMT analog; not definitively confirmed | Web search |

**⚠️ FLAG:** Australia's legal status for DPT could not be definitively confirmed. If Australia covers tryptamines broadly under Schedule 9, DPT would be controlled. Editorial review of Australian TGA scheduling lists is recommended.

---

## Clinical Trials

### ClinicalTrials.gov

**One relevant trial identified:**
- **NCT02033707** — "Effects of Hallucinogens and Other Drugs on Mood and Performance"
  - Status: COMPLETED
  - Phase: Phase 1
  - Conditions: Healthy participants
  - Sponsor: Johns Hopkins University
  - Relevance to DPT: This is a general hallucinogen study; DPT's specific role in this trial requires verification through the full protocol.

**No active or recruiting DPT-specific clinical trials found on ClinicalTrials.gov.**

### Historical Controlled Clinical Studies

Three controlled/pilot clinical studies were published in 1973–1980 (see History section):
1. Soskin, Grof, Richards 1973 [Ref 23] — low-dose DPT in psychotherapy
2. Grof, Soskin, Richards, Kurland 1973 [Ref 24] — DPT-assisted psychotherapy in alcoholism (N=103, controlled)
3. Richards et al. 1980 [Ref 25] — DPT as adjunct in cancer patient psychotherapy (N=30, pilot)

These are the only published controlled trials with DPT in humans and represent the full body of clinical evidence identified.

---

## Community Feedback Analysis

No community feedback was submitted in Part A2 of the brief.

---

## Gaps & Flags

### Safety-Critical Flags

1. **⚠️ FATAL DOSE UNKNOWN:** No LD50 or toxic dose threshold published for DPT in any species or in humans. The fatal case (Neukamm et al. 2024 [Ref 1]) involved aspiration, not direct pharmacological overdose — so no human pharmacological lethal dose can be inferred.

2. **⚠️ MAOI CONTRAINDICATION:** The life-threatening serotonin syndrome risk with MAOIs is a class-based inference (from DPT's dual mechanism as 5-HT agonist + SERT substrate). No DPT-specific MAOI interaction study has been published. This must be clearly flagged as critical inferred data, not confirmed data.

3. **⚠️ SEIZURE RISK AT HIGH DOSES:** Animal data (Tyagi et al. 2023 [Ref 31]) confirms proconvulsant effects at 20 mg/kg in mice; rat data at 30 mg/kg. The fatal case involved a seizure after insufflation at unknown dose. Dose-dependent seizure risk should be prominently flagged.

4. **⚠️ AUSTRALIA LEGAL STATUS:** Not confirmed. The generation agent should note uncertainty; editorial review recommended.

### Research Gaps

5. **No human pharmacokinetic data:** No published studies on DPT's bioavailability, Tmax, Cmax, T½, volume of distribution, or metabolic pathway in humans. All PK inferences are class-based analogy from DMT and other tryptamines.

6. **No CYP enzyme data:** DPT's interactions with hepatic cytochrome P450 enzymes are unknown. This is relevant for drug interaction profiling.

7. **No published metabolite identification:** The metabolic products of DPT in humans or animals have not been characterized in published literature.

8. **Limited NIMH-PDSP binding profile:** Ray 2010 [Ref 2] included DPT in a broad receptor profiling study across 51 sites, but specific Ki values beyond the serotonin receptor family were not extractable from the abstract. The full receptor affinity profile remains incompletely published.

9. **No self-administration studies:** DPT's reinforcing properties have not been tested in animal self-administration paradigms. The dependence liability assessment rests on class-level evidence only.

10. **No human dose-response studies:** The dose ranges in the brief are drawn from historical clinical use (TiHKAL, clinical literature) and community reports, not from controlled pharmacological studies.

11. **Duration data gap for oral route:** The brief shows total duration of 2–4 hours for oral, with onset 20–60 min but no peak specified. No published controlled study has characterized the time-course of DPT effects systematically.

12. **No metabolic pathway published for DPT:** Whether MAO-A is the primary route of elimination (as with DMT) is assumed but not confirmed.

### Seed Data Discrepancies

No major contradictions between seed data and published sources were found. The following additions/corrections are supported:

- **SMILES, PubChem CID, InChIKey, molecular formula, molecular weight:** All were blank in the seed data; all have now been verified and provided above.
- **Pharmacological class "Serotonin 1A receptor agonist":** Confirmed as partial agonist (52% intrinsic activity at 5-HT1A; IC50 0.1 µmol/L) — the characterization is technically accurate though "partial agonist" would be more precise.
- **Brief characterization as "emerging":** Appropriate given limited post-1980 clinical research; however, DPT has been known since the 1950s–1960s and was investigated in controlled trials in the 1970s. Its re-emergence as a research chemical/NPS warrants the "emerging" label in the contemporary context.