Vet,So its pointless to refrigerate it? Thats my feelings. Ive had the issues you describe just storing it in the cold.
It lasts a long time in the sealed unopened vial? (I've read up to 10years?)
How long its safe if opened and noncontaminated is a question I dont know.
Generally speaking all drugs should be stored at the temperature indicated by the manufacturer. That said, MOST oil based drugs are stored at room temperature and most water based are refrigerated.
The expiration date is the longest date from manufacture that the drug will have a known activity. After the expiration date, the drug begins to break down and there is no guarantee that they have the same degree of activity--meaning a higher dose may be needed if you are taking it past the expiration date or that there will be no effect from the drug. That said, most oil based drugs have a shelf life of 1-3 years, with certian hormones being shorter (depoprogesterone for example) and some being longer (depoestradiol). Most water based drugs have shelf lifes of 6 months to 4 years. Again this varies dramatically by individual drug. There is also no gaurantee on how long after expiration a drug is "effective". Realistically, if its only a month, maybe two months expired for an oil based drug, its doubtful that you will notice a significant decrease in effect. If its 6 months, there will probably be decreased activty, but the strength of the placebo effect will probably carry it through. No one that I'm aware of evaluates drugs past the expiration date, so its all an anecdotal guess.
As far home brewed, homemade drug concoctions, I have no idea what a reasonable shelf life would be. Realistically, its probably a year, maybe longer for oil based drugs if the drug is made in a reasonably stable environment and stored in a cool, dry place (ie a dark closet). If there are any signs of crystals, films, seperation, or discoloration, it stands to reason its either contaminated or its destabilized and isn't as effective (or safe to use).
