How long are the supplements viable for? I am not ready to do the program yet as I want to just focus on really cleaning up the diet for the next 2-3 months, but I also don't want the supplements to expire.

Take it at your own pace. Supplements are viable for 1 full year from the time you receive them. Refrigerate the probiotics to extend their potency if you are not going to take them for 2-3 months.