Found an MSDS:
https://www.phillips-safety.com/wp-c...p-SDS-2018.pdf
The only actual ingredient listed is glycerol ("pure" form of glycerin), but it states it is less than 0.02% glycerol. The other 99.98% of the contents are "trade secrets."
Other reading I've done suggests that glycerin is the basis for most anti-fog products. If the concentration is really that low, I could see some product variability due to less than complete mixing explaining the fairly large number of reviews that say it doesn't do much of anything.
I have sent an inquiry through Leupold's contact form. Will post up if I get a response.