Considering the reports of PMMA here: https://www.thevespiary.org/rhodium/Rhodium/pharmacology/pmma.txt (https://www.thevespiary.org/rhodium/Rhodium/pharmacology/pmma.txt)
and Shulgin's commentary in Pihkal, which reads:
" In truth, METHYL-MA is a well studied drug, at least in animals. In both mice and rats, it is an exceptionally potent agent in creating the state of catatonia. Animal studies, prompted by the clandestine synthesis of METHYL-MA, have shown that there is indeed locomotor stimulation and some central effects, but these effects are somehow different than those of a simple amphetamine-like agent. The experimenter's conclusions, based on its structural resemblance to 4-MA and its proclivity to produce catatonia in some animal species and the ever-present possibility that there might be unsuspected neurochemical changes to be seen with its use, are that human experimentation should be discouraged. I have come to the same conclusion, but in my case this is based on a much more succinct observation: I tried it and I didn't like it."
I believe that PMMA should be considered a toxin, and should not be taken by any experimenter, and the same is true for PMA itself. If someone desires to make any simple derivative of it, such as 3-iodo or 3-bromo PMMA, I advice that person to make sure that the tasted sample does NOT contain PMMA, and still be wary of any possible side effects as the compound is carefully titrated from 0.5-1mg and up to an actice dose.