I'm prescribed 8 1ml 200mg/ml vials per month. I've purchased a mini fridge to store the excess, is there anything else I can do preserve the longevity?

Not long story, but and unimportant story leading up to my clinic prescribing me 400mg/week's worth. I'm using 120mg/week. Some of them are already past their expiration. I know test lasts well past the expiration date, especially pharma, but is there anything I should be doing to preserve them beyond refrigeration? Would freezing help or lead to degradation?

I'd like to save up a lifetime stash while the gettin's good, or at least for as many cycles as I'd like for life if I end up choosing to do that.

Thank you.