It’s no secret that serums are having a moment. Scroll through any skincare Insta-feed, blog or product junkie’s medicine cabinet, and you’re sure to see the latest must-have skin serum popping up right between the cleanser and moisturizer. But what exactly is all the hype about…and should you start to incorporate serums into your skin care regimen? To get the skinny, we reached out to Dermatologist Dr. Adam Geyer for an expert take on the benefits and differences between different types of skin serums, and the right products to try.The Basics“As people have become savvier about their skin-care routines, layering has become increasingly prevalent. By using a serum, people are able to intensify the strength of their regimen or round out the ingredients they are applying to their skin to provide a more comprehensive approach to anti-aging and hydration,” Geyer says. “Serums are usually formulated with a higher concentration of active ingredients so that a few drops are sufficient to cover the entire face. The texture is usually lighter than a moisturizer, which allows for it to be used as a stand-alone product for someone with oilier skin, or used under a moisturizer for someone with normal to dry skin.”The Application“Serums should be applied twice daily. They are the first products that should be applied to the skin after cleansing and toning. A sunscreen should be applied over the serum in the morning and a moisturizer appropriate for an individual’s skin type should be used over the serum at night.” Geyer suggests. “Apply the serum with one or two fingers (so as to avoid wasting the serum on your hands) and massage thoroughly into the skin.”The OptionsNow that you’ve got the basics and application covered, which product should you choose? Well, the answer depends on your objective, naturally. “There are many different types of serums and both the active ingredients and the texture of the serum can provide different functions and benefits. Serums formulated in a water base tend to be well suited to those with oily skin and those with a richer texture, or formulated with oils, tend to work well for those with drier skin. However – it is really the combination of active ingredients that defines the serum – with the main six categories being antioxidants, peptides, retinol, growth factors, alpha and beta hydroxyl acids, and unique botanicals,” Geyer says.Ahead, find six of our favorite serums that are perfect for your nighttime routine or morning makeup prep.