It seems logical: A medicine cabinet in the bathroom should be the perfect spot to hold over-the-counter and prescription medications and vitamins, supplements and herbal remedies. But the reality is that the bathroom is one of the least temperature- and moisture-stable rooms in the house, and heat and moisture can make medicines less effective. Instead, the best bet to store your pills is in the bedroom. Keep them in a drawer where the moisture and temperature levels are pretty consistent year-round. If you're worried about kids finding them, get a drawer lock from any home improvement store.