Research chemicalPsychedelicThioether2C-T phenethylamine
2C-T-21
Also known as 2,5-dimethoxy-4-(2-fluoroethylthio)phenethylamine
2C-T-21 is a 2-fluoroethylthio member of the 2C-T family. Reported by Shulgin as a moderately potent psychedelic with stimulant colouring, it has appeared sporadically as a research chemical with no safety characterisation.
01 Overview
2C-T-21 bears a 4-(2-fluoroethylthio) group on the 2C scaffold. Shulgin described a psychedelic experience with a lighter, more energetic quality than 2C-T-2 or 2C-T-7. It is one of several fluorinated 2C-T analogues that circulated briefly online.
Human exposure remains rare, and the MAOI caution and absence of toxicology that define the 2C-T class apply fully here.
02 Mechanism
Partial agonist at 5-HT2A/2C receptors; the fluoroethylthio group at the 4-position confers moderate potency.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Reported common | 8–12 mg | Oral | Shulgin range; duration several hours. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Energetic psychedeliaStimulating visual effects with a lighter body load in some reports. | moderate | Anecdotal | |
| Mood liftPositive, sociable mood at moderate doses. | moderate | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Stimulant overactivationRaised heart rate and jitteriness reported at the upper range. | Moderate | Common | Anecdotal | |
| MAOI interaction riskMAO-dependent metabolism makes MAOI combinations potentially fatal. | Life-threatening | Rare | Anecdotal |
06 Legal status
United Kingdom
Psychoactive Substances Act 2016
as of Jan 2026
United States
Schedule I (Federal Analogue Act)
Analogue when intended for consumption. · as of Jan 2026
07 References
PiHKAL: A Chemical Love Story (2C-T-21 entry)Shulgin & Shulgin, 1991
08 Discussion0 comments
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This page is reference information, not medical advice. Doses and protocols are documented as they appear in the clinical literature and in practice — describing them is not a recommendation to use them. Countermeasures listed here are not a substitute for a physician. Legal status varies by jurisdiction and changes.