4-PRO-MET

4-PrO-MET (4-propionyloxy-N-methyl-N-ethyltryptamine) is a synthetic psychedelic tryptamine and a prodrug of the well-known psychedelic 4-HO-MET (metocin). As a prodrug, 4-PrO-MET is not directly active at serotonin receptors — instead, it is converted in the body into 4-HO-MET through hydrolysis of its propionyl ester group. This means the subjective effects of 4-PrO-MET are widely considered to be equivalent to those of 4-HO-MET, with differences primarily in onset timing and duration.

Chemistry

4-PrO-MET belongs to the tryptamine class and is structurally characterized by a propionyloxy substituent at the 4-position of the indole ring, along with methyl and ethyl groups on the terminal amine nitrogen.

• IUPAC name: 3-[2-(ethyl(methyl)amino)ethyl]-1H-indol-4-yl propanoate
• Molecular formula: C₁₆H₂₂N₂O₂
• Molecular weight: 274.36 g/mol
• PubChem CID: 169222171

The propionyl ester group at position 4 distinguishes 4-PrO-MET from its parent compound 4-HO-MET (which has a free hydroxyl group) and from 4-AcO-MET (which carries an acetyl ester). These ester prodrugs share the same active metabolite — 4-HO-MET — but may differ in their pharmacokinetic profiles, including how quickly they reach peak plasma levels and how efficiently they are converted.

Pharmacology and Mechanism of Action

4-PrO-MET itself has minimal direct pharmacological activity. After oral ingestion, esterases and other enzymes in the gastrointestinal tract and liver cleave the propionyl group, releasing the active metabolite 4-HO-MET (metocin). This process is analogous to how psilocybin (4-PO-DMT) is converted into psilocin (4-HO-DMT) in the body.

The active metabolite 4-HO-MET exerts its psychedelic effects primarily through agonism at serotonin 5-HT₂A receptors, which are widely regarded as the principal target responsible for the visual and cognitive effects of classic psychedelics. Published receptor binding data for 4-HO-MET shows high affinity for 5-HT₂A receptors (Ki values in the low nanomolar range). It also binds at 5-HT₂C and 5-HT₂B receptors with moderate affinity.

Like other tryptamine psychedelics, 4-HO-MET does not produce significant activity at dopamine receptors and has low affinity for adrenergic receptors, which contributes to its relatively mild cardiovascular side-effect profile compared to phenethylamine psychedelics.

Subjective Effects

Because 4-PrO-MET is a prodrug of 4-HO-MET, its effects closely mirror those reported for metocin. Users commonly describe:

• Visual effects: Enhanced color perception, geometric patterns, visual distortions, and at higher doses, complex fractal imagery. 4-HO-MET is often noted for producing particularly vivid and colorful open-eye and closed-eye visuals.
• Cognitive effects: Enhanced pattern recognition, conceptual thinking, thought acceleration, and a generally lucid headspace compared to other psychedelics like psilocybin mushrooms.
• Emotional effects: Euphoria, empathy, increased emotional sensitivity, and occasional episodes of laughter or giddiness. The emotional tone is frequently described as light and recreational.
• Physical effects: Mild nausea (especially during onset), yawning, changes in body temperature perception, and pupil dilation.

A distinguishing characteristic of 4-HO-MET among tryptamine psychedelics is its reputation for a relatively light cognitive load — users often report that they can think more clearly during the experience compared to substances like psilocybin or 4-AcO-DMT, which tend to produce deeper ego dissolution and psychological introspection.

Onset, Duration, and Tolerance

The onset of effects after oral ingestion of 4-PrO-MET typically occurs within 25–40 minutes, which may be slightly slower than 4-HO-MET due to the additional metabolic step required to cleave the propionyl group. The total duration of effects is approximately 4.5–5.5 hours, with aftereffects lasting an additional 1.5–2.5 hours.

Like all serotonergic psychedelics, 4-PrO-MET produces rapid tolerance. After a single use, tolerance develops almost immediately and typically requires 7–14 days to return to baseline. Cross-tolerance exists with other serotonergic psychedelics including LSD, psilocybin, DMT, mescaline, and other 4-substituted tryptamines.

Harm Reduction

As a research chemical with limited published safety data, harm reduction practices are especially important:

• Start with a low dose. Individual sensitivity varies significantly. A common dose range is 8–15 mg orally, but first-time users should consider starting at the lower end or below.
• Use a milligram scale. Accurate dosing is critical at these low weights. Volumetric dosing (dissolving a known quantity in a measured volume of solvent) can improve accuracy.
• Test your substance. Use reagent testing kits (Ehrlich, Marquis, Hofmann) to verify identity. Fentanyl test strips are recommended for any substance obtained from unregulated sources.
• Set and setting. Choose a comfortable, safe environment and a positive mental state. Have a trusted, sober companion present.
• Do not combine with MAOIs, lithium, tramadol, or other serotonergic substances due to the risk of serotonin syndrome.
• Avoid redosing during the onset period, as the prodrug conversion may delay peak effects.

Legal Status

4-PrO-MET is not explicitly scheduled under the United Nations Convention on Psychotropic Substances. However, its legal status varies by jurisdiction:

• In Germany, it is not listed in the BtMG (Narcotics Act, Betäubungsmittelgesetz) but may fall under the NpSG (New Psychoactive Substances Act, Neue-psychoaktive-Stoffe-Gesetz).
• In the United States, it is not specifically scheduled but could be prosecuted under the Federal Analogue Act as a substantially similar compound to a Schedule I substance (psilocin/4-HO-DMT).
• In the United Kingdom, it is a controlled substance under the Psychoactive Substances Act 2016.
• In Canada, it may be considered an analogue of psilocin under the CDSA (Controlled Drugs and Substances Act).

Legal classification is subject to change. Always check current local legislation before handling or possessing this substance.

Related Compounds

4-PrO-MET is part of a family of 4-substituted tryptamines that share structural and pharmacological relationships:

• 4-HO-MET (metocin) — the active metabolite of 4-PrO-MET
• 4-AcO-MET — acetyl ester prodrug of 4-HO-MET
• 4-HO-DMT (psilocin) — the active metabolite of psilocybin
• 4-AcO-DMT (psilacetin) — acetyl ester prodrug of psilocin
• 4-HO-MiPT — a related but distinct psychedelic tryptamine
• Psilocybin (4-PO-DMT) — the naturally occurring phosphorylated prodrug of psilocin