4-HO-DPT

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Wikipedia

4-HO-DPT
Clinical data
Other names4-OH-DPT; 4-Hydroxy-N,N-dipropyltryptamine; Deprocin
Routes of
administration		Oral[1]
Drug classNon-selective serotonin receptor agonist; Serotonin 5-HT2A receptor agonist; Serotonergic psychedelic; Hallucinogen
ATC code
  • None
Legal status
Legal status
  • DE: NpSG (Industrial and scientific use only)
Pharmacokinetic data
Onset of action15–45 minutes[2]
Duration of action5–8 hours[2]
Identifiers
  • 3-[2-(dipropylamino)ethyl]-1H-indol-4-ol
CAS Number
PubChem CID
ChemSpider
UNII
CompTox Dashboard (EPA)
Chemical and physical data
FormulaC16H24N2O
Molar mass260.381 g·mol−1
3D model (JSmol)
  • CCCN(CCC)CCc2c[nH]c1cccc(O)c12
  • InChI=1S/C16H24N2O/c1-3-9-18(10-4-2)11-8-13-12-17-14-6-5-7-15(19)16(13)14/h5-7,12,17,19H,3-4,8-11H2,1-2H3 checkY
  • Key:MZLRMPTVOVJXLW-UHFFFAOYSA-N checkY
  (verify)

4-HO-DPT, also known as 4-hydroxy-N,N-dipropyltryptamine or as deprocin, is a psychedelic drug of the tryptamine and 4-hydroxytryptamine families related to psilocin (4-HO-DMT).[1][2] It is taken orally.[1][2]

The drug acts as a non-selective serotonin receptor agonist, including of the serotonin 5-HT2A receptor.[3] It produces psychedelic-like effects in animals.[3] The drug is closely structurally related to other psychedelic tryptamines such as dipropyltryptamine (DPT), 5-MeO-DPT, and psilocin (4-HO-DMT), among others.[1]

4-HO-DPT was first described in the scientific literature by David Repke and colleagues in 1977.[4][5][3][6] It was encountered as a novel designer drug in 2012.[7][8][9][3] A presumed prodrug, 4-AcO-DPT, is also known, and has likewise been encountered as a designer drug.[3]

Use and effects

According to Alexander Shulgin in his book TiHKAL (Tryptamines I Have Known and Loved) and other publications, the dose and duration of 4-HO-DPT are unknown.[1] At a dose of 20 mg orally, there were possibly threshold effects and nothing more.[1][10] Per Shulgin, there were not enough observations to know what dose would result in activity or what the effects would be.[1] However, the occurrence of threshold effects at a dose of 20 mg was suggestive that "something is nearby".[1]

Subsequently, 4-HO-DPT and its presumed prodrug 4-AcO-DPT have been encountered as novel designer drugs, substantiating the notion that more significant effects do indeed occur with 4-HO-DPT at sufficiently high doses.[7][8][9][3] Based on user reports, 4-HO-DPT has an onset of 15 to 45 minutes, a duration of 5 to 8 hours, and produces hallucinogenic effects including psychedelic visuals among others.[2]

Interactions

Pharmacology

Pharmacodynamics

4-HO-DPT activities
TargetAffinity (Ki, nM)
5-HT2A1.6 (EC50Tooltip half-maximal effective concentration)
103% (EmaxTooltip maximal efficacy)
5-HT2B2.2 (EC50)
94% (Emax)
5-HT2C212 (EC50)
83% (Emax)
Notes: The smaller the value, the more avidly the drug interacts with the site. Sources: [3]

4-HO-DPT acts as a high-efficacy partial agonist to full agonist of the serotonin 5-HT2A, 5-HT2B, and 5-HT2C receptors.[3] It has more than two orders of magnitude greater potency as an agonist of the serotonin 5-HT2A and 5-HT2B receptors than as an agonist of the serotonin 5-HT2C receptor.[3] Hence, it shows considerable selectivity for the serotonin 5-HT2A receptor over the serotonin 5-HT2C receptor.[3]

Compared to psilocin (4-HO-DMT), 4-HO-DPT has about the same potency and efficacy as a serotonin 5-HT2A receptor agonist, has about the same potency but is much more efficacious as a serotonin 5-HT2B receptor agonist (EmaxTooltip maximal efficacy = 39% vs. 94%, respectively), and has about the same efficacy but approximately 10-fold lower potency as a serotonin 5-HT2C receptor agonist.[3]

4-HO-DPT produces the head-twitch response, a behavioral proxy of psychedelic effects, in rodents.[3] Its potency for inducing the head-twitch response in mice is about 4- or 5-fold lower than that of psilocin.[3]

Pharmacokinetics

The metabolism of 4-HO-DPT has not been studied.[11][12]

Chemistry

4-HO-DPT, also known as 4-hydroxy-N,N-dipropyltryptamine, is a substituted tryptamine and 4-hydroxytryptamine derivative related to psilocin (4-HO-DMT).[1]

Synthesis

The chemical synthesis of 4-HO-DPT has been described.[1][4] It is said to be difficult to make.[1]

Crystal structure

In 2019, Chadeayne and colleagues solved the crystal structure of the fumarate salt of 4-HO-DPT.[13] The authors describe the structure as follows: "The asymmetric unit contains one 4-HO-DPT cation, protonated at the dipropylamine N atom. There are also two independent water molecules, and half of a fumarate ion present."[13]

Analogues

Analogues of 4-HO-DPT include dipropyltryptamine (DPT), 5-MeO-DPT, psilocin (4-HO-DMT), 4-HO-DET, 4-HO-DiPT, 4-HO-MPT, 4-HO-EPT, 4-HO-PiPT, and 5-HO-DPT, among others.[1] 4-AcO-DPT is a presumed prodrug of 4-HO-DPT.[3]

History

4-HO-DPT was first described in the scientific literature by David Repke and colleagues in 1977.[4][5][3][6] Subsequently, it was described in further detail by Alexander Shulgin in his 1997 book TiHKAL (Tryptamines I Have Known and Loved).[1] The drug was encountered as a novel designer drug in Europe in 2012.[7][8][9][3]

Society and culture

Germany

4-HO-DPT is controlled in Germany under the Neue-psychoaktive-Stoffe-Gesetz (NpSG; New Psychoactive Substances Act) as of July 2019.[14][15][16][17]

Sweden

4-HO-DPT is classified as a "dangerous substance" Sweden, which means that it cannot be legally bought or sold without a special permit, though it is still not yet an illegal drug.[18]

Switzerland

4-HO-DPT is a controlled substance in Switzerland as of 2020.[19]

United Kingdom

4-HO-DPT is a Class A drug in the United Kingdom, as a result of the tryptamine catch-all clause.[20]

United States

4-HO-DPT is not an explicitly controlled substance in the United States. However, the drug is a close analogue of psilocin (4-HO-DMT), which is a Schedule I controlled substance in this country, and hence sale for intended human consumption could be illegal under the Federal Analogue Act.[citation needed]

See also

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 Shulgin A, Shulgin A (September 1997). TiHKAL: The Continuation. Berkeley, California: Transform Press. ISBN 0-9630096-9-9. OCLC 38503252. "4-HO-DPT".
  2. 1 2 3 4 5 Malaca S, Lo Faro AF, Tamborra A, Pichini S, Busardò FP, Huestis MA (December 2020). "Toxicology and Analysis of Psychoactive Tryptamines". International Journal of Molecular Sciences. 21 (23): 9279. doi:10.3390/ijms21239279. PMC 7730282. PMID 33291798. 4-OH-DPT is the 4-hydroxylated DPT derivative first synthesized by Shulgin et al. [82]. 4-OH-DPT is a light beige or white powder [54] that acts as a 5-HT2A partial agonist. 4-OH-DPT also shares structural similarity with psilocin [83]. Effects are dose dependent, with onset at 15–45 min and duration of 5–8 h. According to user reports, synthetic 4-OH-DPT produces visual effects and hallucinatory states [84].
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Klein AK, Chatha M, Laskowski LJ, Anderson EI, Brandt SD, Chapman SJ, et al. (April 2021). "Investigation of the Structure-Activity Relationships of Psilocybin Analogues". ACS Pharmacology & Translational Science. 4 (2): 533–542. doi:10.1021/acsptsci.0c00176. PMC 8033608. PMID 33860183. Repke synthesized several other psilocin homologues, including 4-hydroxy-N-methyl-N-ethyltryptamine (4-HO-MET), 4-hydroxy-N-methyl-N-isopropyltryptamine (4-HO-MIPT), 4-hydroxy-N,N-dipropyltryptamine (4-HO-DPT), and 4-hydroxy-N,N-diisopropyltryptamine (4-HO-DIPT).63,64
  4. 1 2 3 Repke DB, Ferguson WJ, Bates DK (1977). "Psilocin analogs. 1. Synthesis of 3-[2-(dialkylamino)ethyl] -and 3-[2-(cycloalkylamino)ethyl] indol-4-ols". Journal of Heterocyclic Chemistry. 14 (1): 71–74. doi:10.1002/jhet.5570140113. ISSN 0022-152X.
  5. 1 2 Bauer BE (2 January 2020). "Scientists Solve the Crystal Structure of the Psilocbyin Derviative 4-HO-DPT". Psychedelic Science Review. Retrieved 8 October 2025.
  6. 1 2 Ferguson WJ, Bates DK, Repke DB (1977). "Psilocin analogs. 1. Synthesis of 3-[2-(dialkylamino)ethyl] -and 3-[2-(cycloalkylamino)ethyl] indol-4-ols". Journal of Heterocyclic Chemistry. 14 (1): 71–74. doi:10.1002/jhet.5570140113. ISSN 0022-152X.
  7. 1 2 3 "EMCDDA–Europol 2012 Annual Report on the implementation of Council Decision 2005/387/JHA (New drugs in Europe, 2012)". www.euda.europa.eu. 2 July 2024. Retrieved 9 October 2025.
  8. 1 2 3 Palamar JJ, Acosta P (January 2020). "A qualitative descriptive analysis of effects of psychedelic phenethylamines and tryptamines". Human Psychopharmacology. 35 (1) e2719. doi:10.1002/hup.2719. PMC 6995261. PMID 31909513.
  9. 1 2 3 Tanaka R, Kawamura M, Hakamatsuka T, Kikura-Hanajiri R (2021). "Identification of six tryptamine derivatives as designer drugs in illegal products". Forensic Toxicology. 39 (1): 248–258. doi:10.1007/s11419-020-00556-5. ISSN 1860-8965. Retrieved 16 October 2025.
  10. ↑ Shulgin AT (2003). "Basic Pharmacology and Effects". In Laing RR (ed.). Hallucinogens: A Forensic Drug Handbook. Forensic Drug Handbook Series. Elsevier Science. pp. 67–137. ISBN 978-0-12-433951-4.
  11. ↑ Berardinelli D, Montanari E, Malaca S, Zaami S, Busardò FP, Huestis MA, et al. (2022). "4-Hydroxy-N,N-methylpropyltryptamine (4-OH-MPT) in vitro human metabolism". Toxicologie Analytique et Clinique. 34 (3): S96. Bibcode:2022ToxAC..34Q..96B. doi:10.1016/j.toxac.2022.06.147.
  12. ↑ Carlier J, Malaca S, Huestis MA, Tagliabracci A, Tini A, Busardò FP (December 2022). "Biomarkers of 4-hydroxy-N,N-methylpropyltryptamine (4-OH-MPT) intake identified from human hepatocyte incubations". Expert Opinion on Drug Metabolism & Toxicology. 18 (12): 831–840. doi:10.1080/17425255.2022.2166826. PMID 36609205.
  13. 1 2 Chadeayne AR, Pham DN, Golen JA, Manke DR (2019-11-28). "Bis(4-hydroxy-N,N-di-n-propyltryptammonium) fumarate tetrahydrate". IUCrData. 4 (11) x191469. Bibcode:2019IUCrD...491469C. doi:10.1107/S241431461901469X. ISSN 2414-3146.
  14. ↑ "Verordnung zur Änderung der Anlage des Neue-psychoaktive-Stoffe-Gesetzes und von Anlagen des Betäubungsmittelgesetzes" (PDF). Bundesgesetzblatt Jahrgang 2019 Teil I Nr. 27 (in German). Bundesanzeiger Verlag. July 17, 2019. pp. 1083–1094. ISSN 0341-1095.
  15. ↑ "§ 4 NpSG" (in German). Bundesamt für Justiz [Federal Office of Justice]. Retrieved December 10, 2019.
  16. ↑ "§ 3 NpSG" (in German). Bundesamt für Justiz [Federal Office of Justice]. Retrieved December 10, 2019.
  17. ↑ "Gesetzentwurf der Bundesregierung: Entwurf eines Gesetzes zur Bekämpfung der Verbreitung neuer psychoaktiver Stoffe" (PDF) (in German). Deutscher Bundestag. May 30, 2016. p. 20. Drucksache 18/8579.
  18. ↑ "Tio nya ämnen kan klassas som narkotika eller hälsofarlig vara" (in Swedish). Folkhälsomyndigheten [Public Health Agency of Sweden]. February 14, 2018. Retrieved August 24, 2020.
  19. ↑ "Verordnung des EDI über die Verzeichnisse der Betäubungsmittel, psychotropen Stoffe, Vorläuferstoffe und Hilfschemikalien" (in German). Bundeskanzlei [Federal Chancellery of Switzerland]. Retrieved January 1, 2020.
  20. ↑ "Schedule 2: Part I: Class A Drugs". Misuse of Drugs Act 1971. UK Government. Retrieved August 20, 2020.