A lot of it is just the submitting reports on the manufacturing and testing. Lots of procedural stuff, and them asking for more information on various aspects. Based on what I read though.

Havent found any reports on risk or results from trials on humans. Just various changes in cell responses in varied tissues that they studied in mice.

Regardless, mice studies dont translate to human very well. 80 percent of stuff that works in mice doesnt work in humans.