This case has certainly damaged the good reputation of the Nurmagomedov clan, which previously had truly great fighters and even always held champion titles in their respective classes.
I saw in my trusted news broadcast that there was an official response from Usman Nurmagomedov that the failure of the test was due to the presence of substances in the medicine he was taking and that the medicine was prescribed by doctor after he experienced health problems.
Usman mistake was that he did not notify the Athletic Commission or (CSAC) of this problem from the start.

But I haven't seen any clear news about whether he was actually stripped of his lightweight title belt or not because I haven't been able to find any developments.
This is quite serious problem for the Nurmagomedov family and especially for Usman himself.