4-PrO-MET, also called 4-propionyloxy-MET or O-propionyl-4-HO-MET, is a synthetic tryptamine ester related to 4-HO-MET. A propionyl group is attached to the oxygen at the 4-position of the indole ring, while the terminal nitrogen carries methyl and ethyl groups. The compound has appeared in online research-chemical listings, but peer-reviewed studies directly establishing its pharmacology, metabolism or effects in humans are not available.
Chemistry and relationship to 4-HO-MET
4-PrO-MET is the propionate ester of 4-HO-MET. It is structurally distinct from 4-AcO-MET, which carries a smaller acetyl group at the same oxygen position. The change from acetate to propionate adds one carbon to the ester substituent; it does not make the two compounds interchangeable.
The chemical relationship to 4-HO-MET makes ester hydrolysis a possible metabolic pathway. However, no compound-specific human or laboratory metabolism study has confirmed the extent of this conversion for 4-PrO-MET.
Pharmacology
No direct receptor-binding or functional assay for 4-PrO-MET was identified among the peer-reviewed sources examined here. Studies of 4-HO-MET and 4-AcO-MET show that related 4-substituted tryptamines can interact with several serotonin receptors, including 5-HT2A, but those findings do not establish the potency or efficacy of the propionate ester (Receptor binding profiles for tryptamine psychedelics, 2023).
Reported effects and human evidence
Available descriptions of 4-PrO-MET are anecdotal, with no support from controlled human studies. Comparisons with 4-HO-MET or 4-AcO-MET may reflect the shared chemical scaffold, but they do not establish that the compounds produce the same subjective effects, time course or adverse reactions.
Research limitations
Direct evidence remains the main gap. No validated human pharmacokinetic profile, clinical case series, acute toxicology assessment or long-term safety study has been published for 4-PrO-MET. Its proposed conversion to 4-HO-MET remains a structural hypothesis rather than a demonstrated human metabolic pathway.
Related tryptamines
4-PrO-MET is related to 4-HO-MET and 4-AcO-MET. All three share the N-methyl-N-ethyltryptamine framework, but carry different oxygen substituents at the 4-position.
