Health and beauty items that you don't use or want to use for their intended purpose can often be put to a different use such as using lotions for shaving. If unopened they could be donated to a shelter. This is a page about using it up health and beauty products.
When you have sunscreen that is past it's 'use by' date, you should not use it to protect your skin from the sun. It could possibly be useful as a lotion, if you are certain there is no bacteria present.
A manager at a CVS drugstore told me that the sales are recycled every 3 weeks, so if what you want isn't on sale and you can wait to stock up, be aware that this is a possibility and may also be true of other stores. This may no longer be practiced, but it was true as of a few months ago.