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?
A hair serum is a lightweight, usually silicone-based treatment designed to smooth the hair’s surface and add instant shine. Unlike heavier oils or thick creams, serums don’t soak into the strands—instead, they coat the hair to protect it from frizz, dryness, and daily damage.
The right hair serum can help control flyaways, improve the appearance of split ends, and shield hair from heat styling. Some formulas even nourish the scalp or help replenish moisture. Whether you want to boost shine, enhance softness, or smooth your strands, hair serums can be a helpful addition to your haircare routine.
Best Hair Serums For Frizz
Biolage Professional Smooth Proof Serum
If your hair tends to get frizzy or puffy in humid conditions, reach for this smoothing serum. It’s made with camellia oil and glycerin and creates a protective layer against humidity that helps lock out frizz for up to 24 hours.
Redken Frizz Dismiss Instant Deflate Oil-in-Serum
Score smooth, shiny-looking locks with this lightweight hair oil-in-serum. The hybrid formula contains babassu oil and helps diminish frizz and tame unwanted volume while boosting shine and softness. Plus, it doubles as a heat protectant, offering protection against temperatures up to 446 degrees Fahrenheit.
Best Hair Serums for Dry Hair
Matrix Food For Soft Multi-Use Hair Oil Serum
This serum-oil hybrid enriched with avocado oil and hyaluronic acid helps lock in moisture, leaving the hair smooth, shiny, and hydrated for up to 72 hours. The lightweight, non-greasy formula is suitable for all dry hair types and can be used on damp or dry hair to help add softness and long-lasting nourishment.
Kérastase Nutritive 8H Magic Night Hair Serum
Your skin isn’t the only thing that can benefit from a good night’s sleep—with this luxe overnight serum, your strands can benefit, too. Work the nourishing formula throughout damp or dry hair before hitting the sheets and enjoy softer, smoother hair come morning.
Best Hair Serums For Damage
Pureology Strength Cure Dream Healer Serum
Coloring your hair can be a great way to showcase your personality, but it can also be hard on your hair. To help replenish brittle, over-processed hair, reach for this serum. It’s made with lactic acid and citric acid and helps strengthen weak, fragile hair, diminishing breakage by up to 85%.
Shu Uemura Art of Hair Ultimate Reset Overnight Hair Serum
Formulated with Japanese rice extract and peptides, this luxe overnight hair serum helps repair and reverse damage to the hair fiber caused by chemical processing and heat styling. It helps fight up to one year of visible surface damage to the hair in a single use and leaves damaged strands up to 95% stronger and three times smoother. Consider it the perfect way to revitalize your hair after a fresh dye job.
Kérastase Blond Absolu 2% Pure Hyaluronic Acid Serum
Bleach is notoriously damaging and can contribute to split ends, brittleness, and widespread breakage. This hair serum helps to combat those concerns. It’s made with hyaluronic acid and instantly hydrates the hair while helping to diminish breakage and boost shine. You can even apply it to your scalp after a blonding service to help support your scalp’s moisture barrier.
Best Hair Serums For Heat Protection
Mizani Thermastrength Heat Protecting Serum
If you frequently heat style your curly or coily hair, we suggest adding this hair serum to your routine ASAP. It’s formulated with nourishing shea butter and features anti-breakage technology to help guard your natural hair against damage from hot tools such as your flat iron or blow dryer. Like many hair serums, it also helps tame frizz for smoother-looking locks.
Kérastase Resistance Sérum Thérapiste Hair Serum
This multitasking serum doesn’t just help protect against heat damage—it also helps replenish heat-damaged hair. The formula boasts a powerful blend of protein and peptides and helps safeguard strands against temperatures up to 450 degrees Fahrenheit. At the same time, it repairs and renews for soft, silky strands.
Best Serums For Scalp Care
Biolage Professional Full Rescue Invigorating Scalp Serum
If you’ve noticed your hair becoming thinner than you’d like, consider adding this scalp serum to your routine. The rosemary and niacinamide-infused formula fortifies hair from root to tip and helps improve hair’s resistance to breakage to support a full, healthy-looking mane.
Matrix Instacure Tension Reliever Scalp Ease Serum
This leave-in formula provides a refreshing cooling sensation to help ease tension on the scalp caused by tight hairstyles. It’s loaded with good-for-your-scalp ingredients, including biotin and avocado oil, and provides nourishment without any buildup or flaking. The formula is suitable for all hair types and textures, but we find it particularly useful for those with natural hair who often wear their hair in protective styles.
Best Multi-Tasking Hair Serums For All Hair Types
Pureology Style + Protect Shine Bright Taming Hair Serum for Frizzy Hair
This formula transforms from a rich cream to a lightweight hair serum as you warm it between your hands. Dispense a pea-sized amount of product onto your palms, rub your hands together to activate the formula, then work it throughout your mane to tame frizz, control flyaways, and add shine.
Shu Uemura Art of Hair Essence Absolu Nourishing Overnight Hair Serum
Make the most of your nightly eight hours by raking one to two pumps of this lightweight serum throughout your mid-lengths and ends before going to sleep. The luxe formula with Japanese red camilla oil helps smooth, nourish, and tame the hair overnight so hair is soft and ready to style come sunrise (no need to rinse!)
Frequently Asked Questions (FAQs)
What's the difference between hair serums and hair oils?
Hair serums are lightweight, silicone-based treatments that coat the hair’s surface to boost shine and control frizz. Hair oils, by contrast, are oil-based and typically a bit richer in texture. While serums are primarily hair stylers, hair oils can help moisturize and nourish your hair from the inside out. If you want something that does both, reach for an oil-in-serum. As the name suggests, these hybrid formulas combine the frizz-taming benefits of a serum with the deep replenishment of a hair oil for healthy-looking (and -feeling) hair.
How do I apply 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 mid-lengths 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: Let the serum absorb for a minute or two 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.
Are serums bad for your hair?
No professionally-formulated hair serum should damage your strands. Still, there are some misconceptions surrounding hair serums. For instance, many believe that hair serums will make their hair oily, but that’s not the case—any greasiness comes from overapplication, not the product itself. 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 a deep conditioning mask to thoroughly cleanse and moisturize your hair after using products containing silicones.
Do you put serum on wet or dry hair?
Generally speaking, the best time to use a hair serum is after a shower, while your strands are still damp. However, some formulas can be applied to dry hair, too. Read the package instructions for guidance on when (and how) to apply your chosen serum, and remember 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.
Next Up: Do You Need a Hair Protein Treatment?
Use our salon locator to discover more ways to achieve your healthy hair goals.
Header image credit (left to right): @pureology, @kerastase_official
