All effective skincare routines, even the most basic ones, have four major tenets: cleanse, treat, moisturize, and protect. Most of those steps are self-explanatory. Cleanse simply means wash your face. Moisturize means to, well, use moisturizer. Protect means wearing sunscreen every day. If you do those three things, you’re way ahead of lots of other dudes—and on your way to great skin.

But that “treat” step is tricky. What exactly does that mean? Basically, treat means that between washing your face and applying moisturizer is your chance to address specific issues like acne, wrinkles, rosacea, irritation, or anything you would like to change about your skin. And to do that quickly and effectively, allow you need to befriend serums.

Think of serums as a power boost to your skincare routine—like the fire flower in Super Mario Bros or the espresso shot in your morning drip. In skincare terms, serums are highly concentrated with ingredients that are designed to target and treat specific issues. Other products, like moisturizers, offer more general protection. Serums, on the other hand, generally have higher doses of active ingredients that can more effectively work on certain skin problems.

Ingredients To Look For In A Serum

Often, serums will be named for what they do (anti-aging or hydration, for example), which makes decoding ingredients easy. But you’ll also usually see ingredients listed on the outer packaging to tell you what is doing all the work. Depending on what you’re treating, you’ll likely see some of these common players:

Hyaluronic Acid: Our bodies naturally produce hyaluronic acid which can absorb and hold 1,000 times its weight in water, making it a powerful ingredient to help maintain healthy moisture levels in your skin. Hyaluronic acid is important for everyone, but especially if you struggle with dry skin issues.

Vitamin C: Antioxidants help neutralize free radicals from sunlight and even counteract the skin impacts of pollution, which can cause dullness, uneven skin tone, and even skin cancer. Vitamin C is one of the most powerful antioxidants out there and is typically the most common antioxidant you’ll see in skincare.

Niacinamide: Niacinamide is a form of vitamin B3, but it’s also an antioxidant. It can lighten dark spots, smooth skin texture, even out skin tone, and generally strengthen the skin from the inside out.

Retinol: Derived from vitamin A, retinol is one of the most well-studied and powerful ingredients in skincare. It helps speed up cell turnover, which in turn not only helps prevent wrinkles and signs of aging but can also help treat and prevent acne breakouts. It can sensitize the skin, especially when you first start using it, so apply it only at night and always wear sunscreen during the day.

How To Use A Serum

Adding a serum to your routine is pretty simple: Apply serum on clean skin after washing your face. Use a patting motion with your hands to help press it into your skin instead of rubbing it on like a moisturizer. Some hydrating serums can be used in place of moisturizer, but you generally want to follow a serum with some sort of moisturizer to help lock it in your skin. Retinol should only be applied at night, but most other serums can be used in the morning, too. When in doubt, read the usage instructions on the label.

Choosing from the hundreds—possibly thousands—of serum options out there can be daunting. Start with this list of top-rated selections and you’re on your way to the skin of your dreams.

BEST VITAMIN C SERUM

Drunk Elephant C-Firma Day Serum

Ascorbic acid, the form of vitamin C found in this formula, “is the gold standard because it has the widest range of benefits,” according to Drunk Elephant founder Tiffany Masterson. This version comes in powder form, which you mix into the pump yourself to make sure it’s as fresh (and effective) as possible. Other vitamin C serums oxidize quickly when exposed to air, but because you mix it yourself, this one stays fresh for around 6 months, she says.

BEST ANTI-AGING SERUM

Neutrogena Rapid Wrinkle Repair Anti-Wrinkle Face Serum

Vitamin A-derived retinol is the gold standard for fighting wrinkles, but it can also help with dark spots, uneven skin tone and texture, and even breakouts by helping to speed cell turnover. This effective serum contains retinol as well as ultra-hydrating hyaluronic acid for a one-two punch.

BEST BRIGHTENING SERUM

Olay Vitamin C + Peptide 24 Serum

Yes, there is antioxidant powerhouse vitamin C in this serum, but it also contains skin-building peptides to help strengthen your skin. That’s not to mention the inclusion of niacinamide, a powerful antioxidant in itself, which helps fade dark spots and assists in skin cell regeneration.

BEST RETINOL SERUM

Differin Gel

Before a few years ago, this dermatologist favorite was only available by prescription. Now you can buy it over the counter at your local drugstore, which means the powerful acne-squashing (and wrinkle-reducing) serum can start transforming your skin even faster.

BEST SERUM FOR BLACKHEADS

The INKEY List BHA Blemish + Blackhead Serum

To fight clogged pores that show up on your face as blackheads, turn to salicylic acid. Unlike other hydroxy acids which exfoliate the surface of your skin, salicylic acid actually gets down into your pores to help clear up blockages gently.

BEST SERUM FOR DARK SPOTS

Topicals Faded Serum for Dark Spots & Discoloration

Fading dark spots and smoothing acne scars is one of the hardest things to do in skincare. Thanks to the combination of niacinamide and a variety of acids like kojic and tranexamic in this formula (as well as antioxidant botanical extracts), this serum is incredibly effective for treating discoloration and related skin concerns.

BEST NIGHT SERUM

Kiehl’s Midnight Recovery Concentrate

After working to protect itself all day, your skin goes into recovery mode at night repairing damage and rebuilding itself. Slather on this serum before bed to help it along thanks to botanical oils like moisturizing squalane and calming lavender. Bonus: It’s so hydrating you don’t even need to put a moisturizer on afterward.

First Aid Beauty Facial Radiance Niacinamide Dark Spot Serum

Niacinamide is often used to fade dark spots and smooth uneven skin tone, but it can also help improve the durability of your skin. That means your skin can benefit from it even if you don’t have sun spots or post-acne scars. This serum is packed with the powerful ingredient, as well as soothing botanical licorice root and antioxidant golden kiwifruit.

BEST ANTIOXIDANT SERUM FOR OILY SKIN

Skin Ceuticals Silymarin CF

Vitamin C serum has an important place in everyone’s skincare routine, but come vitamin C serums don’t play well with oily or blemish-prone skin. This one, however, is specifically formulated for oily skin and not only provides strong antioxidant protection but also contains silymarin and salicylic acid to help control oil and fight breakouts.

BEST PROTECTING SERUM

Dr. Loretta Intense Replenishing Serum

Not only does this moisturizing serum deliver a tidal wave of hydration to your skin (so much you can see it instantly plump), but it also contains ceramides which help strengthen your skin like mortar in a brick wall. It also protects against environmental damage throughout the day.

BEST HYALURONIC ACID SERUM

The Ordinary Hyaluronic Acid 2% + B5

The reason you see hyaluronic acid in so many skincare products, particularly moisturizers, is that the magical ingredient can hold 1,000 times its molecular weight in water—which translates to incredible hydrating abilities when applied to the skin. Give your skin a good drink with serum every morning and night.A

BEST RESURFACING SERUM

Dr. Dennis Gross Advanced Retinol + Ferulic Texture Renewal Serum

You usually find antioxidant ferulic acid in vitamin C serums because it enhances the skin-protecting factor. In this serum, however, it’s combined with retinol—and that pairing helps smooth uneven texture, shrink the appearance of pores and reduce fine lines revealing smoother, clearer skin.

BEST PERSONALIZED SERUM

Atolla Custom Serum

Remember that serums are best used to target specific issues. But what if you don’t exactly know where to start or what ingredient is best for what you’re trying to treat? That’s where a customized serum like this one from Atolla comes in. Fill out an online quiz about your skin concerns and the brand will custom mix a serum specifically for you.

BEST MULTIPURPOSE SERUM

Dermalogica Smart Response Serum

Inspired by technology like your iPhone that can predict what you need, this advanced serum targets four issues: redness, dehydration, wrinkles, and dull skin. Targeted ingredients go to work when they detect one (or more) of these issues in your skin without you doing anything besides slathering it on.

BEST REDNESS REDUCING SERUM

La Roche-Posay AR Intense Redness Reducing Serum

Not only does this serum deeply moisturize even the driest skin, but it’s specifically designed for sensitive skin, reducing the redness and irritation that can come along with it. Apply it morning and night to calm down irritated skin and protect it from environmental factors that can make redness flare-up.