For the best results, you should apply a serum when your skin is still damp. This is especially true if you’re using a serum that contains hyaluronic acid. When your skin is damp, it’s easier for the product to better penetrate the layers of your skin. However, to make the effects of enhanced hydration last longer, it’s usually best to pair your body serums with something like applying a topical body oil, lotion, or cream moisturizer shortly after. This helps to lock in moisture and minimize the chances of experiencing dryness.