Its huuuge effort to make them. Find the right combo for some certain wound (possibly test hundreds before finding anything good), find out which combo does not give to much penalty, possibly use lye etc. expensive ingredients to do this.
And when you apply it... Its slow as hell! Its been like 6 hours in bed and only 2 points of severe mauling have healed.
Elixirs should be made way faster, equivalent to the great efforts to make them, it should be like 2 points an hour or some such, otherwise I don't really see point in making them for any wounds that are treatable by other means.