Here is a link to a great read about the ethics of using natural musks.
”In the case of Siberia, the species of deer being hunted is not a species threatened with extinction, and the hunting lottery system means that only a finite number of musk deer are killed in the region each year. The most valuable by-product of the Siberian musk deer is indeed its musk sac, but not a single part of the deer is wasted: the meat is eaten, the hide is made into clothing and leather, and the hooves used to make glue.
During a legal, licensed hunt, the kill is as humane as possible (shooting instead of trapping) and the proceeds help support local families who live off the seasonal hunt. Hunting has always played an important role in the local economies of wherever a valuable resource lies, be it salmon, deer, oud, or sandalwood.”