I bought 50 mg reta vials , and planned to use it as an add on to 15 mg of tirzepatide, so doses were going to be low. I did not feel comfortable with taking one or two mg doses out and so 25 to 50 needles going in and out as a risk of introducing contamination and then leaving it in the fridge for months seemed a bit risky. So i just reconstituted it, took 1/5 out -10mg and put it in a sterile vial, diluted it to make dosing a bit easier and put the other 40mg back in the fridge. it has bac , so hopefully no bacteria should grow so the main concern would be peptide degradation at fridge temperatures. without spending many hours searching for actually accurate scientific information on retatrutide degradation rates that may not yet be available , I figure it is unlikely to deteriorate at more than a percent or two a month and should be fine for a few months. I personally am not especially concerned about a few percent peptide degradation or leaving it in the fridge for a few months. Freezing it is possibly a better alternative, lower risk of bacterial growth. Repeated freeze thaw cycles definitely causes peptide degradation, but one or two cycles are unlikely to cause more than a few percent degradation. it would probably make more sense to divide it up into vials at the start and only thaw out the vial when you needed it and leave it in the fridge after thawing. It really depends on what you are comfortable with, most of them are overfilled by 5 to 10%, so the dose is not going to be way off if a few percent deteriorate. And bacterial or fungal growth could occur if left in the fridge for months even with bac, I would definitely not be injecting it intravenously , but subcutaneously, you have an immune system and the risk is of an unpleasant and painful abscess, and I can't say I have heard of people complaining about this actually happening from using peptides , so it cannot be common.