Thiopropamine
Thiopropamine (TPA) is a synthetic stimulant and research chemical structurally related to methiopropamine (MPA), differing from amphetamine by the substitution of a thiophene ring for the phenyl ring. First synthesized in 1942, it did not emerge on recreational markets until early 2016, appearing shortly after MPA was banned in the UK. It is estimated to be roughly one-third the potency of amphetamine and produces amphetamine-like stimulant effects.
Contents
Dosage & Duration
Dosage
Duration
Subjective Effects
The experience is that of a mild, functional stimulant with a rapid onset when insufflated. The character is broadly amphetamine-like, carrying moderate euphoria alongside a slight empathogenic edge and a modest increase in libido. Compared to related thiophene stimulants such as methiopropamine, it has been described as somewhat smoother, and the comedown is reported to be relatively soft, with residual afterglow sometimes noticeable the following morning.
Physical
Physical stimulation is moderate and manageable. Appetite suppression appears milder than with most stimulants, with users remaining able to eat during the experience. Insufflation produces noticeable nasal burning.
Stimulation
The stimulation is functional and amphetamine-like, arriving quickly and fading over the course of an evening with a comparatively gentle comedown.
Cognitive
The headspace remains clear and functional, with a pleasant euphoric and mildly empathogenic tone rather than an overwhelming rush.
Emotional
Reagent Testing
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Pharmacology
Pharmacodynamics
The precise mechanism of action of thiopropamine has not been definitively established. Based on its structural relationship to amphetamine (in which the phenyl ring is replaced by a thiophene ring), it most likely functions as a norepinephrine-dopamine reuptake inhibitor and/or releasing agent, though with roughly one third the potency. As a propan-2-amine, thiopropamine is also expected to act as a competitive monoamine oxidase inhibitor.
Pharmacokinetics
Thiopropamine is likely metabolized into active 4-hydroxymethiopropamine and thiophene S-oxides. These metabolites are further deaminated by CYP2C enzymes in the liver, producing the inactive compound 1-(thiophen-2-yl)-2-propan-2-one, a phenylacetone derivative. Propan-2-amines as a class are not metabolized by monoamine oxidases.
Tolerance
Harm Potential
Addiction & Dependence
Psychological
Classified as habit-forming by harm reduction resources, suggesting some potential for psychological dependence typical of stimulant compounds.
History & Culture
Thiopropamine was first synthesized in 1942, though it remained obscure for over seven decades before entering the recreational drug market. The compound only emerged commercially in early 2016, appearing shortly after regulatory action was taken against the structurally related substance MPA…
Legality
By Country
Automated synthesisInformation aggregated and synthesized using an autonomous workflow built by Josie Kins.
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