Hair Serums: Your Guide to Smoother, Shinier-Looking Hair

If you have a multi-step skincare routine, you're likely already familiar with the power of a good face serum so why not give your hair the same care? Hair serums are styling treatments that work like a top coat for your strands, instantly boosting shine and taming frizz. Much like their skincare counterparts, they provide targeted results for various surface-level concerns. When used correctly, hair serums can help deliver stunning shine, smoothness, and manageability to your hair.

Not sure where to start or how to pick the best serum for your needs? We’ve got you covered. Together, we’ll break down the benefits of hair serums, show you how to use them effectively, and share our favorite formulas from L’Oréal’s portfolio of professional brands. By the end, you might just realize that hair serum was the missing piece your hair routine needed all along.

What Does a Hair Serum Do?

A hair serum is typically a silicone-based styling treatment that coats the surface of your hair to add instant shine and smoothness. 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, reduce the appearance of split ends, and shield hair from heat styling. There’s even a specialized formula, known as scalp serum, that nourishes the scalp and helps replenish moisture. Whether you want to boost shine, enhance softness, or smooth your strands, hair serums can make all the difference.

Best Hair Serums For Frizzy Hair

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 fend off 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°F (230°C).

Best Hair Serums for Dry Hair

L'Oréal Paris Elvive Hyaluron + Plump Moisture Plump Serum

Thirsty strands get a much-needed boost with this paraben-free leave-in serum, powered by hyaluronic acid to deliver intense hydration without weighing hair down. The lightweight, non-sticky formula helps replenish moisture and plumps hair fibers, leaving hair looking fuller, softer, and healthier from root to tip.

Matrix Food For Soft Multi-Use Hair Oil Serum

Formulated with avocado oil and hyaluronic acid, this serum-oil hybrid 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 Damaged Hair

L'Oréal Paris Elvive Glycolic + Gloss High Shine Leave-In Serum

Turn up the shine and restore vitality to damaged hair with this innovative leave-in serum. Infused with a 4% Glycolic Acid Complex, it seals and laminates the hair cuticle for next-level gloss, leaving hair softer, shinier, and able to reflect maximum light—a must-have for dull or damaged strands.

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%.*

*Versus a non-conditioning shampoo.

Shu Uemura Art of Hair Ultimate Reset Overnight Hair Serum

Formulated with Japanese rice extract and peptides, this luxe overnight hair serum helps improve the appearance of damaged hair 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.

*When compared to a non-conditioning shampoo

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. Formulated with hyaluronic acid, this serum provides instant hydration 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°F (232°C). At the same time, it improves the appearance of hair, making strands feel soft and silky.

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)

Hair serum vs. oil? What's the difference?

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:

1. 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.
2. 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.
3. 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 you should know about. 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.

Currently Trending: The “Skinification” of Hair

You might be wondering where this hair serum obsession came from, or why everyone seems to be talking about serums these days. The answer lies in the growing “skinification” of haircare, where skincare-inspired rituals are taking over our routines from root to tip. Here’s what’s trending right now:

• Glass Hair & Liquid Hair: Achieving ultra-glossy strands is all over TikTok (where #@glasshair boasts over 900 million views). To replicate this viral look at home, reach for a smoothing serum like Redken Frizz Dismiss Instant Deflate Oil-in-Serum. It’s perfect for creating that much-coveted mirror-like shine.

• Scalp Care as Skincare: On Reddit communities like r/HaircareScience, users are treating their scalps like their skin, seeking out ingredients like biotin or niacinamide often found in skincare routines. Scalp serums are surging in popularity because we know: healthy-looking hair starts with a healthy scalp.

Ready to bring some of these trends into your routine? Start with one (or two) serums tailored to your goals, and watch what happens next. We’d also love to see results. Share your skin transformation with us on social using #skincaredotcom for a chance to be featured

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