get some before you can’t
I spent about $35 about 9 months ago and got a couple year supply of the “Equestrian Apple-Flavored” brand.
Pretty sure I had a mild case a few weeks ago and it never got beyond a mild cold.
The only difference between the horse-brand and the human brand is that the medium doesn’t have the same quality control requirements - and it’s a gel vs. a pill.
One notch equals about 50 lbs body weight as far as a dose.