O-Desmethyltramadol (O-DSMT) is an opioid that has primarily been used indirectly due to it being a primary metabolite of the analgesic tramadol. Since the 2010s it has occasionally been used on its own as it has been sold through the grey market/research chemical market.
It has a longer duration than tramadol and more typical opioid-like effects, although it still impacts monoaminergic systems to an extent that might somewhat influence the effect profile.
O-Desmethyltramadol = O-DSMT; Desmetramadol; O-Demethyltramadol
Molecular formula: C15H23NO2
Molecular weight: 249.354 g/mol