With some products, the surface of the pill will change color when some components oxidize. When this happens, the surface of the tablets usually becomes darker and mottled. You should discard these tablets. You can also see this kind of discoloration inside of some two-part capsules, and you should discard these also. (Some products normally have a mixed-color surface, and you should get to know what they look like when you first buy them so you will know when they change.)

The best course of action is to buy what you need for a 1- to 3-month period or up to 6 or 8 months if it is more convenient, and store unopened bottles in a cool (but not necessarily refrigerated), dark room. If you buy a large amount, you may keep the unopened bottles in the refrigerator, but be sure to bring them to room temperature before opening them, and don't store them in the fridge once they have been opened.

Multi-compartment Storage Boxes
One last note that will make it easier for you to take supplements if you are taking more than a few: There are multi-compartment storage containers, similar to fishing tackle or sewing boxes, but with a rubber gasket seal to keep out air. They come with six to 16 chambers, to hold a number of different supplements. Label each chamber unless you clearly recognize the different supplements. If you have too many for the box, you can mix two in one chamber as long as you recognize the difference.

The advantage of having one of these multi-compartment boxes is that you only have to open one lid each time you want to take your supplements. Since you might be taking many different products at one time, this is an enormous time saver. And if you have arthritis, it will help reduce the stress on your hands from opening so many bottles so frequently.

Another way to accomplish this is to purchase some empty pharmacy vials and set aside some time to fill up a 1-week supply of morning and evening doses all at once. It is a good idea to have different size vials for your morning and evening for recognition, in case the doses are different.

Both of these methods have one further advantage, in that the original storage bottle for each supplement is opened less frequently, reducing exposure of the main supply to air and humidity. You should not have great difficulty keeping supplements safely.