Each product has been tested until it's empty. Skincare products often take time to show results, and this helps give me a more accurate read on how good it actually is. Occasionally a product that I react so poorly to that I can't finish it. I'll make a note of that when it applies. Thank goodness for Sephora's return policy, am I right?
There's also a whole strategy behind how I introduce new products to my routine, which you can read about by clicking the link below.