YOU GUYS IT IS SO COLD TODAY. So cold. When I woke up this morning my telephone informed me that it was 2° outside, but with the wind chill it felt closer to -15°. I did not give up opportunities to move to Massachusetts and Maine to experience this kind of weather further south.

With that in mind, I’m not going to have a great #outfitselfie for you today, since I’m bundled up in everything I can think to keep me warm. (All my warmest clothes, it seems, are some variation on tan.) But! We’ve got a great series coming to you over the next several weeks, with today being the premiere: Know Your Face. As you know, I’m a bit skincare-obsessed. One day each week for the next few weeks, we’ll be focusing on a different skincare product and what you need to know about it. I’ll also give my recommendations for products that have worked well for me. Today’s product: serums.

Serums are an often-overlooked product because, honestly, your face is fine without them. You absolutely need to wash and moisturize your face, but what serums provide is supplemental. That said, however, they’re hard workers who definitely earn their paycheck.

What serums do is add an intensive layer of protection and repair to your face. They contain higher concentrations of the key ingredients that you would find in your other products, which means fast action. I have five serums in my rotation and each of them is nothing less than a miracle worker.

Daytime Serums

Daytime serums should focus on brightening and protecting. You’re going to be in any number of settings throughout a day, so you should have products on your skin that will keep the good stuff in and the bad stuff out. Also, given that you can’t predict the situations your face will face (ha!), you shouldn’t have too much Product in your product – focus on one or two key ingredients to protect and glow.

Estee Lauder Idealist Even Skintone Illuminator

This Estee Lauder serum came with a gift set that included my beloved moisturizer and eye cream, and honestly, I wasn’t that impressed at first. AT FIRST. This is why you should always give a few weeks for a product to really work with your skin before you pass judgment. After a few weeks of using the Idealist serum, I was at a friend’s party where someone said, “Nora,  you are looking LUMINOUS these days.” Luminous.

This serum contains salicylic acid (skin clearing!) and vitamin C (skin brightening!) and it’s a touch drying, so if you use it, be prepared to moisturize well afterwards. It also has mica, which provides a sheen without having obvious sparkle.

Renee Rouleau Vitamin C & E Treatment

I really love vitamin C during the day, guys. It’s just so good for your skin. I use this Renee Rouleau serum on the days when my skin needs a bit more nourishment than the Idealist offers. The vitamin C works overtime with brightening properties, while the vitamin E helps repair and protect damaged skin. I used it today, knowing that the mega-cold temperatures were going to do awful things to my skin. Added benefit: the combined efforts of vitamins C and E make your sunscreen more effective. Are you wearing sunscreen daily? You should be wearing sunscreen daily. No excuses.

Nighttime Serums

As opposed to daytime, you should focus on repair at night. Whether that means attacking blemishes or infusing your pores with antioxidants, always remember that your skin breathes more deeply while you sleep – meaning it’s going to absorb products much faster and more thoroughly. Nighttime is the perfect time to use more intensive treatments with more complex ingredient lists.

Renee Rouleau Advanced Resurfacing Serum

Also from my girl Renee, this serum contains boatloads of pure retinol, which has amazing exfoliating benefits – simultaneously treating blemishes and preventing wrinkles. I find that retinol is a little too drying for regular use, so I mostly use this guy in the summer, when my skin is OOCO (out of control oily). If you do use retinol products, don’t use them daily – at most, you should use them no more than two nights in a row, with something a bit less harsh on off nights. Your skin will thank you. Also: do not layer retinol products with AHA/BHA products; the combination of exfoliants will not be as effective as if you used one on its own.

Juice Beauty Blemish Clearing Serum

Retinol is amazing, but salicylic acid makes you feel like changes are happening before your eyes. I use this Juice Beauty serum when my skin is going nuts after travel, or after a few nights out too late. The salicylic acid, derived from willow bark (FYI: salicylic acid, beta hydroxy acid, and willow bark extract = essentially the same thing, when you’re reading an ingredients list), combines with vitamins C and E to do some heavy lifting. Again, though, this serum is super exfoliating. Which leads me to my final product:

Estee Lauder Advanced Night Repair

My holy grail of nighttime beauty products. There’s a reason this guy is so popular and has been for so long – because it’s amazing. It contains retinyl palmitate (a lighter-weight retinoid than pure retinol), caffeine (which has major brightening benefits for your skin), hyaluronic acid (moisturizing without oils – key for combination skin like mine), and a ton of antioxidants to protect and repair. The formula, though expensive, lasts for quite a while, and its consistency is divine – silky and soft, it sinks right into your skin. If you’re looking to start using anti-aging products but don’t know where to begin, this is where.

How to use: Serums should be applied after washing and toning but before moisturizing. (Pro tip: when layering products, apply them in order from thinnest to thickest, in terms of consistency.) Allow a few minutes for the serum to sink in fully, and then apply your eye cream and moisturizer. Also, if you find yourself with extra serum on your fingertips after application, you can rub it on the tops of your hands – another part of your body that benefits from anti-aging products!

Next week on Know Your Face: eye creams!