If the word serum brings to mind comic book-style mad scientists or intrepid doctors in jungles carrying syringes full of snake antivenom, that’s no coincidence. Though a face serum is a cosmetic product, it is also a concentrated formula concocted in a lab, with ingredients carefully calibrated to be the (not-so) secret antidote to whatever ails your skin. Sometimes, the serum even comes with a syringe or dropper, reminding us of this liquid’s scientific origins. 

What Is a Face Serum?

Very simply, a face serum is a liquid product that contains a concentrated combination of active ingredients. It’s usually water-based (but can also be oil-based), and compared to lotions, creams and facial oils, it has a consistency that is more easily absorbed through the skin’s natural barrier, so the ingredients can penetrate into the deeper layers of the skin.

The potency of the ingredients is important here — many active ingredients such as vitamins and essential oils degrade quickly, which is why serums come in small bottles, sometimes made of tinted glass, ensuring they stay stable and can be used up before they break down. 

As for what face serums can do for your skin, the answer depends on the latest research of topical ingredients and their effects. Most commonly, you’ll see serums designed to moisturize, protect from the elements, prevent breakouts, promote collagen and elastin production, improve skin texture and reduce dark spots caused by sun exposure. Some serums promise to do many of these things at once, but usually they’ll have just one or two goals so they can contain high concentrations of ingredients.

What’s the Best Way to Use a Face Serum?

In any multistep skincare regimen, a face serum should go on after cleansing and before moisturizing. After you wash your face and gently dry it, even leaving it a little bit wet, the skin will be primed to absorb the serum’s ingredients. Just a few drops should be enough to apply it all over your face.

It’s okay to layer more than one face serum on top of another. Before you do this, though, make sure you test out each one at a time. This way, if it irritates your skin or causes an allergic reaction, you can pinpoint the source.

Layering may also reduce the effectiveness of each serum, because your skin can only absorb so much. Make sure you apply the serum with the lightest consistency first and/or prioritize the one that’s going to treat your main concern, followed by thicker serums or ones you feel are secondary.

When you’re not in a rush to complete your skincare routine, allow a minute or two for each product to penetrate your skin before applying the next layer. Apply your moisturizer last because much of it stays outside the skin’s barrier and can thus seal in your serum ingredients, preventing them from evaporating.

Some serums are fine to use twice a day, while others might cause irritation if you’re exposed to the sun, so read the instructions carefully. 

What’s the Deal With Vitamin C Serums?

Much like our bodies need a daily dose of vitamin C to function well, it turns out that topically applying certain forms of the vitamin can provide our skin with an extra boost too.

Vitamin C is a powerful antioxidant, meaning it can bind to free radicals from the sun, pollution and other bodily processes, and prevent them from damaging cells. That damage shows up in the form of dark spots, mutated cells and decreased collagen and elastin. Preventing it means you’ll have brighter, more supple skin.

Using a vitamin C serum is an excellent way to deliver this star ingredient right to the skin cells that need it.

6 Face Serums We Love

There’s a serum for nearly every skin problem out there. Here are just a few that we love: 

1. GOA Skincare Collagen + Control Facial Serum ($54)
With its proprietary blend of vitamin C and other antioxidants, this powerful face serum for men is designed to reduce inflammation and minimize the appearance of acne, fine lines and pores. Because its ingredients promote collagen production, a pump or two can help skin bounce back after indulging in “vices” like drinking or staying up all night.

2. Ghost Democracy Lightbulb Vitamin C Serum ($34)
Like a lightbulb from within, vitamin C can help brighten skin tone. This serum contains the THD ascorbate form of the vitamin, which stays stable and potent and is easily absorbed through the skin’s lipid cells, making it extra effective.

3. Beuti Skincare Beauty Sleep Elixir ($70)
No fewer than 14 plant-based oils (including Caribbean coral extract, geranium flower and sandalwood nut kernel oils) work in harmony to calm inflammation, hydrate and slow the effects of aging on skin cells. Though it’s called Beauty Sleep, you can also wear this serum during the day under makeup or on its own.

4. Flower and Spice Midnight Beauty Rich Revitalizing Serum ($120)
Accomplish three goals in one with this serum: Botanical oils (prickly pear, plum seeds, macadamia, argan, apricot seed and evening primrose) hydrate; vitamin E and sacha inchi oil improve elasticity, and coriander seed oil soothes inflammation. 

5. Evolve Beauty Hyaluronic Serum 200 ($46)
This rosewater-scented hyaluronic acid serum plumps skin and smooths fine lines and wrinkles. Unlike exfoliating acids like AHA and BHA, hyaluronic acid is extremely hydrating, known for its ability to hold up to 1,000 times its weight in water. 

6. Dr. Loretta Concentrated Firming Serum ($80)
Board-certified dermatologist Dr. Loretta Ciraldo helped develop this high-grade serum with retinol, which promotes cell turnover and increases collagen production while protecting skin from free radical damage. It also contains lipids that moisturize and prevent irritation, leaving skin smooth, clear and firm.