Nearly impossible; an active dose of mescaline is on the order of 300mg, and this is assuming that someone's actually extracted the mescaline itself. Most people take their mescaline along with the pulverized plant matter that contains it, so they end up consuming a lot more than a pill's worth of material.
EDIT: On the other hand 2Cx cuts are not unheard of, as grimmo mentioned.
Your friend isn't entirely incorrect. Mescaline, MDMA, and the 2Cx's are all members of a class of compounds called the
substituted phenethylamines, so called because they start with a
phenethylamine skeleton and make additions to the ring and to the alpha/beta carbons. 2Cx's generally have an amphetamine form created by adding a methyl group to the alpha carbon; for instance, DOB is the amphetamine analogue of 2CB. Since PEA acts as a releaser of dopamine and norepinephrine, most substituted PEAs also release dopamine and norepinephrine, but they can have a variety of other effects as well. For example, many 2Cx's are direct agonists at some 5-HT receptors (notably 5-HT2a), which theoretically makes them psychedelic.
The actions of the 2Cx's are different from mescaline so it's not exactly correct to say that they're "synthetic mescaline". The 2Cx's vary significantly from each other, too...2CI and 2CB feel quite different in my opinion. Also, consuming mescaline-containing plants also indirectly exposes you to other psychoactive alkaloids in the plant.
![:\](https://bluelight.org/xf/BL_Images/Orig_Emoji/wrygrin.gif "wry grin :\")
