The simple answer is yes.
However, there are many factors that can extend the shelf life of the fabulous products you work hard to be able to purchase!
Most skin care products have a symbol on the label that lets you know how long the product is good once it’s been opened: the most widely used icon is a jar with and open cap and a number on it. The number denotes how many months the product is guaranteed from the day you open it.
Most products are good for 6-24 months once they have been opened. Packaging plays a large roll in how this number is determined. An airless pump keeps a product fresh for much longer than a wide mouth jar. The less contamination (for the air or your fingers), the longer your product with stay fresh and stable.
If a product changes color or separates, chances are good that is has expired.
Vitamin C is difficult to keep stable and has a short shelf life. It oxidizes (turns brown) when it is no longer effective.
Most skin care products are sold in containers determined to be the amount an average person would consume, with regular use, in a 3-4 month period.
If you are worried about your products expiring before you use them up, stick with items sold in pumps and tubes instead of jars and store them in a dark, cool environment.
Is there a downside to using expired products?
Again, the simple answer is yes.
When a product is past the expiration date it is no longer effective. For something like a basic moisturizer, this isn’t a concern but for a product containing sunscreen or retinol it’s important to make sure the active ingredients aren’t past their prime.