2C-T-29, also known as 2C-T-PARGY or 2C-T-PROPARGYL or as 4-propargylthio-2,5-dimethoxyphenethylamine, is a designer drug from the substituted phenethylamine family, which was first synthesised by Josh Hartsel and colleagues in 2024. It is a potent agonist at the serotonin receptor 5-HT<sub>2A</sub> in vitro, with a binding affinity (K<sub>i</sub>) of 1.3 nM and an EC<sub>50</sub> of 0.67 nM, acting as a full agonist. While the closely related propylthio compound 2C-T-7 and the allylthio derivative 2C-T-16 are both known to be potent psychedelic drugs in humans, the propargylthio analogue 2C-T-29 is not known to have been tested in humans or other animals. It is a controlled substance in Canada under phenethylamine blanket-ban language.