Scooter has just been changed to Lantus. She was on Vetsulin for quite awhile but after she was treated for a UTI, I couldn’t get her regulated again. My vet suggested Lantus. I got the Lantus pen and am using syringes to draw it out. (I am using the correct syringes). I have read here how some people have gotten several months out of one pen. My question is, does keeping it in the refrigerator prolong the shelf life? Thanks!