That expensive vitamin C serum you've been applying after your hydrating toner? You've probably been neutralizing it before it even has a chance to work. In this episode, Chloe Chen breaks down the actual science behind Korean skincare layering—pH chemistry, molecular weight, and active ingredient compatibility—to help you stop wasting products and start seeing results. Whether you're doing a minimal three-step routine or the full ten steps, you'll learn why order matters more than the products themselves, and how to avoid the barrier-destroying mistakes that cost Chloe a full year of skin repair.

• pH-dependent actives like vitamin C (L-ascorbic acid), AHAs, and BHAs must go on freshly cleansed skin before any toners or essences—applying a pH 5.5 hydrating toner first essentially neutralizes your acids before they can penetrate.
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