Quote Originally Posted by naeem
i read that if you put it in a freezer it will last another 2 or 3 years even if its expired! is that true?
Yes - it is true. I work in pharmaceutical industry and part of my work invloves forced stress studies and probe stability studies of small molecules. Sources of degradation of a drug (meaning loss in percent label claim. ie, how much of actual drug is in dose and corresponding growth in degradates) are: Temperature (heat!), light, moisture (humidity!) and oxygen. Reduction of temperature will stop or dramatically slow drug degradation. Heat will speed up chemical reactions for example. Without delving any furthur - long term storage is best if you vacumn seal and place in freezer. From my experience - you will extend expiry at least 2 yrs maybe more.

I will note, the loss of potency (% label claim) is not much of an issue. The problem is the growth of degradates that grow. These degradates may likely be unknown for otc drugs, and may be even more toxic than drug itself. I do not know if supp companies generate degradate profiles and or stability studies to base the expiry's on their products.