DMAA was originally a decongestant but has been marketed as a “dietary supplement”. It’s dodgy, it seems, to say the least, and the US Food & Drug Administration does not allow its legal sale as a food supplement.
Here’s what Andrey Pavlov doggedly had to say about DMAA in a recent Science-based Medicine post:
“…there is no reasonable way that DMAA can be considered a natural or safe product for sale as a supplement under the DSHEA (US Dietary Supplement Health and Education Act). And even if it did meet DSHEA requirements, this is an excellent example of the dangers of the law in the first place that allow so-called natural compounds to be marketed without prior safety and efficacy testing. The authors recognize that in the vast majority of cases such compounds have no effect at all, whether positive or negative, and the primary harm is in wasting people’s money with claims that are tantamount to fraud. However, there are clearly cases where that is not the case and harm is established about as clearly as one could expect without people dropping like flies. And that doesn’t take into account the less severe or acute harms experienced by vast numbers of people taking untested supplements.”
DMAA supplements sometimes claim “geranium oil” or “geranium extract” as their source. There is no DMAA in geraniums it is added as a synthetic agent. The Wiki page for this compound makes for interesting reading.