CIDRs will not expire in the sense that an expired one will not harm the cow, however, as with any drug, with time they begin to lose some of their efficacy. You generally dont have to worry about that though because most pharmaceutical companies are VERY conservative with expiration dates because they dont even want to risk any mishaps. Also know that the progesterone is time released, most companies put enough progesterone in a CIDR that it will release progesterone for at least 14 days, so if your using a 7-Day protocal you should be able to get 2 uses out of 1 CIDR.
I rinse mine in a bucket of Novalsan/Water and then rinse in clean water upon removal. I also follow the same process prior to putting them back in. You do want to be careful not to store CIDRs wet, I typically use a paper towel and let them air dry before storage. As with any hormone progesterone can be light sensitive so leaving them in the sun is probably not the best idea. I like to store mine in a dark, dry, cool place.
