It stands for Low Dose Naltrexone; it has been used in the treatment of autoimmune diseases in the USA since 1985. They have been studying it for a very long time now.
Two physicians recommended it to me; one from Standford University and Dr Richard Semelka from Chapel Hill NC.
I researched it before trying it and then filled my prescription.
Most recently, functional medicine physicians are speaking very highly of it ,as well as pharmacists.
Research, research, research...it helped me. Maybe try researching the history of LDN and info should come.
There is an international site that our American site on LDN merged with that is very good; they have patient guides and physician prescriber guides, etc.