Tramadol the lowest, as for a person I has quite a few effects that creates a ceiling. 50 mg maybe somewhat (sixty) but more and flat over the mattress or puke fest. Itchy things as well, so with no OD-ing the effects are that negative I recline when available.Flipping the route in the R2 and R1 bonds leads to the R- and S- enantiomers of O-Desmeth