Hello, I'm new to this thread.
Haven't read everything here, but I wanted to post an article on a recent study in July. It showed that dextramethorphan, the main ingredient in cough medicine, had a beneficial effect on myelin.
Researchers wonder, therefor, if dextramethorphan might help MS patients. As both DM and MS involve a breakdown in myelin, I've had my dog on a daily dose of cough medicine. My vet, after reading the study, recommended the dosage based on body weight. I use the OTC brands and formulations that don't have other cold ingredients in them.
Link to article:
Component of common cough medicine may help treat multiple sclerosis - UC Davis Health System Newsroom