4-HO-MPT

4-HO-MPT, also known as 4-hydroxy-N-methyl-N-propyltryptamine or as meprocin, is a psychedelic drug of the tryptamine and 4-hydroxytryptamine families.^[1][2] It is a higher homologue of psilocin (4-HO-DMT) as well as the 4-hydroxyl analogue of N-methyl-N-propyltryptamine (MPT).^[1][2] The drug is taken orally.^[1][2]

4-HO-MPT

Clinical data
Other names	4-OH-MPT; 4-Hydroxy-N-methyl-N-propyltryptamine; Meprocin
Routes of administration	Oral[1][2]
Drug class	Non-selective serotonin receptor agonist; Serotonin 5-HT2A receptor agonist; Serotonergic psychedelic; Hallucinogen
ATC code	None
Identifiers
IUPAC name 3-[2-[methyl(propyl)amino]ethyl]-1H-indol-4-ol
CAS Number	763035-03-6 Y (free base) 77872-42-5 (hydrochloride)
PubChem CID	21786584
ChemSpider	10513074 Y
UNII	37A55H0XW4
CompTox Dashboard (EPA)	DTXSID90904008
Chemical and physical data
Formula	C14H20N2O
Molar mass	232.327 g·mol−1
3D model (JSmol)	Interactive image
SMILES OC1=CC=CC2=C1C(CCN(C)CCC)=CN2
InChI InChI=1S/C14H20N2O/c1-3-8-16(2)9-7-11-10-15-12-5-4-6-13(17)14(11)12/h4-6,10,15,17H,3,7-9H2,1-2H3 Y Key:XFQDDPQGBLSNCN-UHFFFAOYSA-N Y
(verify)

It acts as a non-selective serotonin receptor agonist, including of the serotonin 5-HT_2A receptor.^[3][4] The drug produces psychedelic-like effects in animals.^[2][3]

4-HO-MPT was first described in the scientific literature by 1981.^[5] It was encountered as a novel designer drug by 2021.^[6]

Use and effects

The dose and duration of 4-HO-MPT are listed as "unknown" in Alexander Shulgin's book TiHKAL (Tryptamines I Have Known and Loved).^[1] In more recent publications, the dose has been reported to be 20 to 30 mg orally, with a mean dose of 25 mg.^[2] In a single trial of 8 mg 4-HO-MPT hydrochloride orally from TiHKAL, it was described as producing visual distortion, vertigo, and slight insomnia.^[1]

Interactions

See also: Psychedelic drug § Interactions, and Trip killer § Serotonergic psychedelic antidotes

Pharmacology

Pharmacodynamics

4-HO-MPT activities

Target	Affinity (Ki, nM)
5-HT1A	106–910 (Ki) 490 (EC50Tooltip half-maximal effective concentration) 90% (EmaxTooltip maximal efficacy)
5-HT1B	224
5-HT1D	170
5-HT1E	246
5-HT2A	71–114 (Ki) 3.8–64a (EC50) 53%a–98% (Emax)
5-HT2B	8 (Ki) 3.4 (EC50) 58% (Emax)
5-HT2C	150–203 (Ki) 46–66a (EC50) 83–100%a (Emax)
5-HT5A	664
5-HT6	48
5-HT7	99
α2A	3,625
α2B	1,844
α2C	IA
D2	IA
D3	921
D4, D5	IA
H1	92
H2	IA
M4	IA
σ1	891
σ2	1,166
KOR	IA
NR2B	3,658
SERTTooltip Serotonin transporter	910–1,180 (Ki) 575 (IC50Tooltip half-maximal inhibitory concentration)
DATTooltip Dopamine transporter	IA
Notes: The smaller the value, the more avidly the drug binds to the site. Footnotes: a = Stimulation of IP1Tooltip inositol phosphate formation. Sources: [3][4][7]

4-HO-MPT acts as a potent agonist of the serotonin 5-HT_2A, 5-HT_2B, and 5-HT_2C receptors.^[3][4] It is a partial or full agonist of the serotonin 5-HT_2A receptor, a moderate-efficacy partial agonist of the serotonin 5-HT_2B receptor, and a high-efficacy partial agonist of the serotonin 5-HT_2C receptor.^[3][8] The drug has more than an order of magnitude higher potency as an agonist of the serotonin 5-HT_2A and 5-HT_2B receptors than as an agonist of the serotonin 5-HT_2C receptor.^[3] It also interacts with other serotonin receptors such as 5-HT₆ and 5-HT₇ receptors with high affinity and non-serotonergic targets.^[4] Additionally it inhibits serotonin transporter.^[9]

4-HO-MPT produces the head-twitch response, a behavioral proxy of psychedelic effects, in rodents.^[2][3]

Chemistry

Synthesis

The chemical synthesis of 4-HO-MPT has been described.^[1]

Analogues

Analogues of 4-HO-MPT include methylpropyltryptamine (MPT), 4-AcO-MPT, 5-MeO-MPT, psilocin (4-HO-DMT), 4-HO-DET (ethocin), 4-HO-DPT (deprocin), 4-HO-MET (metocin), and 4-HO-PiPT (iprocin), among others.^[1]

History

4-HO-MPT was first described in the scientific literature by David Repke and colleagues in 1981.^[5] Subsequently, its effects in humans were described by Alexander Shulgin in his 1997 book TiHKAL (Tryptamines I Have Known and Loved).^[1] The drug was encountered as a novel designer drug by 2021.^[6]

Society and culture

Legal status

International

4-HO-MPT is not scheduled by the United Nations' Convention on Psychotropic Substances.^[10]

United States

4-HO-MPT is not scheduled at the federal level in the United States,^[11] but it is possible that 4-HO-MPT could legally be considered an analog of psilocin, in which case, sales or possession with intent for human consumption could potentially be prosecuted under the Federal Analogue Act.^[12]

See also

• Substituted tryptamine