So much of skin care is pure guesswork: For example, you can study up on a certain type of retinol, but you still won’t know how it works for you until you actually test it. And even then, it may take a few rounds to determine whether or not it’s doing the job. Sure, you may know immediately if a product causes an allergic reaction, but oftentimes skin care takes a few days to show signs like clogged pores or increased oil production. “Overtime, [journaling] gives you a lot of clues as to what really your skin gravitates towards,” says Yoon. And, alternatively, what it cannot bear.
Additionally, if you suffer from inflammatory skin conditions, Yoon says keeping a skin care journal can help you keep track of flares and triggers. “When I get flare-ups, I remember it lasting longer than it actually did,” she notes. “I look back to my journal and it was only three days, when it felt like two weeks.” That timestamp can also provide intel on what else was going on in your life—stressful situations, cold weather, and the like—that could have provoked the symptoms.