It seems to me very important to have insulins in a very good state because there can be high blood sugars thinking that you need to eat less or suspecting an occult infection. Which insulin ruins more easily out of the refrigerator (NPH, Lente, or Humalog)?

I believe that all insulins have similar instructions:

Unopened insulin should be stored in the refrigerator until the expiration date on the box. Insulin that is currently being used can be stored in the refrigerator or at room temperature for about a month. Some manufacturers advise that the insulin in their insulin pen cartridges (specifically Novolin NPH Penfill and Humulin NPH disposable pens) are only good for 14 days after opening.

Insulin tends not to perform well after repeated episodes of warming and cooling and warming and cooling. That is why many clinicians advise to keep opened vials/cartridges of insulin at room temperature.

DS