Comment The comments here are missing the point (Score 2) 119
Appetite suppressing molecules are no surprise. In fact, we have one on the market called GLP-1 that works so well, it almost works too well. The big story in the TFA is that this is a "small-molecule" - a relatively simply organic compound that you could synthesize in bulk in a chemistry lab or pharmaceutical plant.
By contrast, GLP-1 is hormone - specifically, a 30-amino acid chain of amino acids called a peptide that folds into a particular tangled shape that makes it work. Peptides are much more difficult to synthesize, and are quite unstable. Our bodies also tend to get rid of peptides quickly, so they don't last very long in the bloodstream.
Just compare how the two look:
GLP1 versus p-Tyramine-O-Sulfate and it is obvious which one is the harder one to deal with.