Change is good, especially when it involves making a cult-classic, revolutionary anti-aging formula even more effective. That’s what just happened to Kiehl’s Powerful-Strength Line-Reducing Concentrate ($62; macys.com). To give you an idea of just how popular this product already was, the company reports that one bottle of this serum is sold every single minute around the world. In total, 5 million bottles have sold since it launched. VIDEO: 5 One-Minute Ways to Feel Your Best MORE FROM