I can confirm it's readily available in France and therefore is probably legal nowadays. However I found this Pubmed article from 2001, which says why it's not legal in France: http://www.ncbi.nlm.nih.gov/pubmed/11317142. The short of it is that it is produced from sarcosine which might originate from cow, and the fear of the so called mad-cow disease which was then very much of a concern, together with that some "contaminants", namely dicyandiamide, dihydrotriazines, creatinine, ions, are or might be formed during the production process. I haven't yet made further investigations, I put that here for what it is worth.