You likely use face serum in your 10-step skincare routine, but serums are worth adding to your haircare repertoire, too. Hair serums are similar to face serums in that they provide targeted results for various surface-level concerns. When used correctly, hair serums can help give strands unparalleled shine, smoothness, and manageability. Think of serums like a top coat of nail polish: You could skip it, but do you really want a dull, chipped manicure?
Whether you’re new to hair serums or need help choosing the best one for your mane, you’ve come to the right place. We’re breaking down everything you need to know about hair serums and recommending our favorite formulas from L’Oréal’s portfolio of professional brands. By the end, you may realize that hair serum was the missing piece your routine needed all along.
What is hair serum?
Hair serums are liquid styling aids designed to coat the surface of hair, providing immediate improvements in texture and appearance. They often feature silicone-based formulas that function like a protective raincoat around strands, locking out frizz, enhancing shine, and defending against environmental stressors like heat and humidity.
What’s the difference between hair serums and hair oils?
Many people use the terms hair oils and hair serums interchangeably, but they’re more like cousins than sisters. Both products help address dryness, split ends, and overall hair health, but their delivery mechanisms differ.
Hair serums are mainly stylers that sit on the outer layer of hair, helping to give locks a sleek and smooth appearance. Hair oils, on the other hand, can also style the hair, but their benefits are a bit more long-lasting. They feature smaller molecules that can penetrate the hair's fiber, helping to moisturize and repair dry or brittle strands.
When torn between a serum or oil, consider your specific hair concerns and whether you need surface enhancement or more intense nourishment. Some formulas even feature a hair serum and oil in one, giving your hair TLC from the inside out.
Who are hair serums best for?
Coarse, frizzy, curly, and dry hair will see the most visible improvements from hair serums, but this product category isn’t exclusive to these hair types. We recommend speaking with a professional stylist to determine if serums are right for you.
Are serums bad for your hair?
No professionally-formulated hair serums on the market should damage your strands. Still, there are some misconceptions surrounding hair serums. For instance, many believe that hair serums will make their hair oily. In reality, serums shouldn't leave your hair slick when properly applied (we’ll get into that shortly). There are also hair serums specifically designed for scalp application, providing targeted benefits in a lightweight formula sans grease.
Another common myth is that silicones in hair serums are bad for your hair. Silicones are generally not harmful to your strands when used moderately and in pro-grade products. In fact, they’re one of the best-in-class options to contain frizz and make locks more manageable. If you’re still concerned about the impact of silicones, use a clarifying shampoo and deep conditioning mask to thoroughly cleanse and moisturize your hair after using them.
How to Use Hair Serum
Using a hair serum really is as easy as 1, 2, 3. Here are the three basic steps you should know about:
- Warm up your serum. Dispense a pea-sized amount of serum into your palms and rub your hands together to warm it up. Serums are often thick, and the warmth helps loosen up the formula so it can spread more evenly through your strands.
- Apply it from mids to ends. Work the serum through clean, towel-dried hair, focusing on the mid-lengths to the ends (the oldest and typically driest part of your hair). If you’re using a scalp serum, follow the instructions on the label and massage it into your roots instead.
- Dry and style your hair. Give your hair a few minutes to absorb the serum before continuing with your usual styling routine. If you think your hair needs more serum, apply half the indicated amount to ensure you don’t overload your hair with product. Hair serum’s viscous consistency makes it easy to overapply, so less is always more.
Do you put serum on wet or dry hair?
Most stylists agree that the best time to use hair serums is when your hair is damp, right after washing it. Some formulas can also be smoothed onto dry hair for shine and frizz control—just keep in mind that a little goes a long way.
Do you leave serum in your hair?
Hair serum is a leave-in product, so there’s no need to rinse it out. However, some formulas are intended for in-shower application—be sure to read the label of your chosen product to gauge its best use.
Which serum is best for your hair?
There is no one-size-fits-all approach to hair serums, so determining the title of “best” is subjective. The best one for you depends on your hair type and needs. While we believe everyone can incorporate a hair serum into their haircare routine, picking the right formula for your hair is key. Consider your hair’s texture, damage level, and styling habits before heading to the store.
Now that you know what hair serums are and how to use them, you can start confidently browsing through options. We’ve rounded up 15 salon-grade hair serums from L’Oréal to consider adding to your lineup.
Best Hair Serums for Frizz
Biolage Professional Smooth Proof Serum
The Smooth Proof Serum from Biolage Professional is inspired by the water-resistant camellia flower, helping to provide anti-frizz smoothness even in 97 percent humidity. Plus, the paraben-free formula is suitable for use on color-treated hair.
Biolage Professional Smooth Proof Serum, $24.00 MSRP
Redken Full Swirl Cream Serum
Many people rely on serums to make hair look sleek and smooth, which is usually a discreet way to say straight. Redken knows that not everyone has straight hair, so they made a serum just for those with waves and curls. Their Full Swirl Cream Serum fights frizz, provides control for all curl types, and enhances the body of each curl.
Redken Full Swirl Cream Serum, $26.00 MSRP
Redken Frizz Dismiss Instant Deflate Oil-In-Serum
Put the brakes on puffy hair with Redken’s Frizz Dismiss Instant Deflate Oil-In-Serum. The formula, which contains the brand’s Smoothing Complex and babassu oil, protects hair from humidity, dismisses unwanted volume, and adds glossy shine.
Redken Frizz Dismiss Instant Deflate Oil-In-Serum, $32.00 MSRP
Best Hair Serums for Damage
L'Oréal Professionnel Absolut Repair Molecular Rinse-Off Serum
Most serums are intended for use post-shower, but L'Oréal Professionnel’s Absolut Repair Molecular Rinse-Off Serum is the exception. This rinse-off, in-shower serum contains patented technology with a 3 percent peptides bonder and five amino acids to refill damaged hair’s molecular structure.* Combine it with the range’s pre-treatment and shampoo to help repair two years of damage in one use.**
*Instrumental test after 15 applications of rinse-off serum.
**Instrumental test on the fiber macromolecular structure after application of pre-treatment + shampoo + rinse-off serum.
L'Oréal Professionnel’s Absolut Repair Molecular Rinse-Off Serum, $48.00 MSRP
Kérastase Blond Absolu 2% Pure Hyaluronic Acid Serum
Frequent bleaching sessions can make bottled blonde hair look and feel straw-like. Luckily, a serum with hydrating ingredients can transform brittle hair. Kérastase’s Blond Absolu 2% Pure Hyaluronic Acid Serum contains hyaluronic acid (a humectant) to hydrate the hair immediately after a blonding service. You can also apply it to a dry scalp that needs additional moisture.
Kérastase Blond Absolu 2% Pure Hyaluronic Acid Serum, $58.00 MSRP
Shu Uemura Art of Hair Ultimate Reset Duo Hair Serum
Damaged hair needs extra TLC, and that’s where Shu Uemura Art of Hair’s Ultimate Reset Duo Hair Serum comes in. Formulated with Japanese rice extract, the serum helps to restore and solidify the hair fiber after frequent bleaching, coloring, or chemical treatments.
Shu Uemura Art of Hair Ultimate Reset Duo Hair Serum, $42.00 MSRP
Shu Uemura Art of Hair Izumi Tonic Rice Water Serum
Bring on the volume with Shu Uemura Art of Hair’s Izumi Tonic Rice Water Serum. This leave-in serum, which contains rice water and ceramides, can help thicken and increase hair diameter and strengthen fragile strands. Hair will look and feel noticeably stronger and fuller.
Shu Uemura Art of Hair Izumi Tonic Rice Water Serum, $69.00 MSRP (90 ml)
Kérastase Nutritive Legacy 8H Magic Night Hair Serum
Lessen hair breakage by up to 99.3 percent with the vitamin-infused Nutritive Legacy 8H Magic Night Hair Serum from Kérastase. Just apply it to your damp or dry hair before you go to sleep, and wake up in the morning with nourished, Instagram-worthy strands—no rinsing required.
*After application of Bain Satin 2 + Masque Intense + 8H Magic Night Serum vs. non-conditioning shampoo
Kérastase Nutritive Legacy 8H Magic Night Hair Serum, $59.00 MSRP
Best Hair Serums for Scalp Care
Matrix Instacure Tension Reliever Scalp Ease Serum
Give your scalp some relief from tight hairstyles with Matrix’s Instacure Tension Reliever Scalp Ease Serum. This leave-in formula provides a refreshing cooling sensation to help ease tension on the scalp, while moisturizing ingredients like avocado oil help nourish dry roots.
Matrix’s Instacure Tension Reliever Scalp Ease Serum, $24.00 MSRP
Kérastase Symbiose Serum Nuit Antipelliculaire Antidandruff Night Serum
Manage dandruff while you sleep with an overnight serum like Kérastase’s Symbiose Serum Nuit Antipelliculaire Antidandruff Night Serum. This highly concentrated P.M. serum is formulated with salicylic acid, a powerful active ingredient to help eliminate the symptoms of dandruff. Check out our full Kérastase Symbiose Review to learn more.
Kérastase Symbiose Serum Nuit Antipelliculaire Antidandruff Night Serum, $59.00 MSRP
Best Hair Serums for Heat Protection
Mizani Thermastrength Heat Protecting Serum
When you flat iron or blow dry your curls, you’ll need a strong heat protectant for the job. Mizani’s Thermastrength Heat Protecting Serum is one of our go-tos. This lightweight heat-protecting serum is packed with shea butter and anti-breakage technology, helping to guard curly and coily hair against damage from hot tools.
Mizani Thermastrength Heat Protecting Serum, $22.50 MSRP
Mizani Press Agent Thermal Smoothing Raincoat Styling Serum
Keep silk presses sleek and tame with the versatile Press Agent Thermal Smoothing Raincoat Styling Serum from Mizani. On wet hair, this layerable blow-dry serum smooths hair’s cuticle, locks in moisture, and protects hair from heat up to 450 degrees Fahrenheit. On dry hair, it can help tame frizz and flyaways to keep your hair looking as smooth as glass.
Mizani Press Agent Thermal Smoothing Raincoat Styling Serum, $25.00 MSRP
Best Multi-Tasking Hair Serums for All Hair Types
Matrix Food For Soft Multi-Use Hair Oil Serum
Treat your hair to Matrix’s Food For Soft Multi-Use Hair Oil Serum, a serum-oil hybrid enriched with avocado oil and hyaluronic acid. This vegan formula provides seven times more moisture for up to 72 hours, leaving hair smooth and shiny. Lightweight and buildable, it acts as a heat protectant up to 450 degrees Fahrenheit, making it perfect for those who crave nourished, radiant locks.
Matrix’s Food For Soft Multi-Use Hair Oil Serum, $31.00 MSRP
Shu Uemura Art of Hair Ashita Supreme Hair Serum
The only thing we love more than an everything shower is not having to wash our hair. Pick up Shu Uemura Art of Hair’s Ashita Supreme Hair Serum to rejuvenate second or third-day tresses. This revitalizing leave-in treatment refreshes unwashed strands, adding shine, smoothness, and softness from the mid-lengths to the ends.
Shu Uemura Art of Hair Ashita Supreme Hair Serum, $69.00 MSRP (90 ml)
Pureology Style + Protect Shine Bright Taming Hair Serum for Frizzy Hair
For shine, flyaway control, and color protection, look no further than Pureology’s Style + Protect Shine Bright Taming Hair Serum. You’ll love how this unique formula transforms from a cream to a serum when you emulsify it in your hands. Just smooth a pea-sized amount over the surface of dry, styled hair as a finishing touch.
Pureology Style + Protect Shine Bright Taming Hair Serum, $31.00 MSRP
Next Up: Our 18 Favorite Hair Oils for Every Hair Type
For more personalized haircare tips, use our salon locator to speak with a stylist in your area.