We’re all familiar with face serums, but have you ever heard of or used a hair serum? Similar to skin serums, hair serums are like trusty sidekicks for your strands. They work with your hair to enhance shine and deeply hydrate, but that's not all: They can also safeguard hair from heat damage, UV rays, and potential breakage. Essentially, hair serums can improve your overall hair health no matter your hair type and texture.
To find the best hair serums on the market, we did a deep dive into the bestselling options across top-rated beauty brands and asked hair experts for their recommendations. During our research, we evaluated each product on a multitude of factors, including its active ingredients, key benefits, and overall effectiveness. We also considered how these serums would pair with a range of hair types and textures. After weeks of research, we were able to determine the 13 best hair serums. Whether you want to tame frizz, add shine, or thicken your hair, these hair serums will give you the best hair day, every day.
Best Overall
Bumble and bumble Hairdresser’s Invisible Oil
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This serum is made with a blend of six oils that deliver deep nourishment to strands.
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This oil is not ideal for people with very fine hair.
Bumble and bumble is a tried-and-true hair care brand that has a collection of incredible products – and the Invisible Oil is one of their bestsellers. What makes this hair oil stand out from the rest is that it offers a range of benefits rolled into one product. For starters, it effectively nourishes strands, which ultimately makes hair softer and smoother; it’s able to successfully tame frizz without weighing roots down; and finally, it provides hair with protection against UV and heat damage, making hair healthier in the long run. Oh, and did we mention that it adds next-level shine?
The reason this product can provide hair with such great benefits is due to its ingredients. Formulated with a blend of six different oils (coconut, argania spinosa kernel, macadamia integrifolia seed, grape seed, sweet almond, and safflower seed oils), it quickly penetrates strands and hydrates hair from the inside out. We will point out that this product is not ideal for people with extremely fine hair, as these oils can weigh it down. However, this hair serum works wonders for anyone with medium to thick hair, completely rejuvenating dry, damaged, and color-treated strands.
Key Ingredients: Coconut oil, argania spinosa kernel oil, macadamia integrifolia seed oil, grape seed oil, sweet almond oil, safflower seed oil | Size: 3.4 oz | Scented: Yes | Key Benefits: Tames frizz, adds shine, provides heat and UV protection
Best Budget
Kristin Ess Weightless Shine Working Serum
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This serum works to seal and smooth damaged hair.
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Some customers note that the fragrance is too strong.
If you’re not already on the Kristin Ess train, we welcome you aboard. This celebrity brand has a slew of effective hair care products, all for an affordable price. One of the most beloved items from the collection is the Weightless Shine Working Serum — this product gets straight to business, hydrating and nourishing strands to provide long-lasting moisture for hours on end. Additionally, it seals and smoothes damaged follicles, helping hair look shinier and healthier after every use. As a bonus, it also protects hair from environmental stressors and even keeps color from fading.
“This lightweight serum was designed to use on wet hair for air-dried texture, but it also tames frizz and adds shine when used on dry hair,” says Alexia Donovan, the director of client services at Barber Surgeons Guild.
For best results, apply a pea-sized amount of serum to your palms and rub them together. Once you get the oil warmed up, work it into towel-dried hair, focusing on the ends. Then, you can either blow dry or air dry hair. If you need an added boost of hydration, apply a bit of this serum to dry hair. (Note: Some customers did say that this product’s fragrance was a bit strong, so if you’re sensitive to smells, just keep that in mind.)
Key Ingredients: Glycerin, sunflower seed oil, mango seed butter | Size: 1.7 oz | Scented: Yes | Key Benefits: Smoothes, hydrates, adds shine, tames frizz
Best Splurge
Guerlain Abeille Royale Scalp & Hair Youth Oil in Serum
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This serum is made from 97 percent naturally derived ingredients, including sustainably sourced honey.
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Though we love the luxe look of the glass bottle, you’ll need to handle it with care when using the serum — otherwise it can easily slip through your hands and break.
If you’re going to splurge, you might as well make it worth it, and this Guerlain hair serum is most definitely worth it. Made with a blend of four sustainably-sourced kinds of honey, this luxe product visibly enhances shine after just one use. In addition to honey, this serum is also made with the brand’s exclusive royal jelly, which provides hair with nutrients, proteins, lipids, and vitamins. And if that wasn’t enough, it also includes panthenol, which locks in moisture and smoothes dry, damaged strands.
This product also happens to be a two-in-one — you can apply it to your scalp without worrying about it weighing hair down. This is because the lightweight liquid instantly absorbs into the scalp – as well as into hair follicles – so hair never looks greasy. The best part? Putting the oil on your scalp can help reduce dandruff as well as promote healthy hair growth.
The statuesque glass bottle adds to the luxury, but be sure to handle it with care (especially while using the serum) because it is breakable.
Key Ingredients: Honey, royal jelly, panthenol | Size: 1.6 oz | Scented: Yes | Key Benefits: Adds shine, hydrates, makes hair fuller and thicker
Best for Fine Hair
Moroccanoil Treatment Light
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This oil is extremely lightweight and instantly absorbs, making it ideal for fine hair.
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Too much oil can come out of the bottle when you pour it.
As someone with thin, fine hair, I know firsthand the struggle of finding a hair serum that doesn’t immediately weigh it down. For years, I was too scared to use hair oil because the word ‘oil’ made me worry that my hair would look, well, oily. Spoiler: That’s not the case. After finally giving in, I decided to try this Moroccanoil favorite – and I’ve never looked back.
First thing’s first: This oil was specifically designed for thin hair, which means it’s not too heavy or thick. The texture is lightweight and almost a bit watery, which makes it easy to warm up in your hands (this also makes it easy to dispense too much, so be sure to pour it out slowly).
Secondly, it adds instant shine, especially on the ends. I love using this oil both when my hair is wet before blowing it dry, as well as after drying it when I need a little moisture pick-me-up. Finally, what I really love about this product is that it tames frizz and flyaways. I can put a light layer close to my roots (where my flyaways are) as well as on my face-framing bangs (where broken ends are), and it won’t weigh either section down. Rather, it conditions my strands and adds noticeable shine.
Key Ingredients: Argan oil, linseed extract | Size: 1.7 oz | Scented: Yes | Key Benefits: Adds shine, hydrates, tames frizz
Best for Thick Hair
Kérastase Elixir Ultime Hair Oil
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This serum has a fruity, musky scent that makes hair smell fresh for days.
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If you have very long or thick hair, you might need to use more than the recommended two pumps (i.e. you’ll have to repurchase often).
Keeping thick hair hydrated and nourished is no easy feat. Luckily, this Kérastase oil-serum came prepared for the challenge. Made with a blend of five nutritious oils (marula, maize, camellia, argan, and procaxi oils), this serum adds moisture to even the thickest, dryest strands. The marula and maize oils work with hair to enhance shine and suppleness, while the camellia and procaxi oils leave your mane soft and manageable. Plus, the argan oil fortifies strands, making them less prone to breakage. On top of that, this serum does the dirty work of taming frizz, even in humidity. The outcome? Soft, shiny, and healthy hair.
This oil also has a luxurious fragrance that features notes of freesia and mandarin, as well as musk extract and sandalwood. While this serum is ideal for people with thick hair, it can also be used on thin hair, too. (For best results, apply this oil to thin hair prior to showering. Then, rinse it out before shampooing. You’ll be able to enjoy all the great benefits of this oil without it weighing down strands.) The only downside of this product is that the bottle doesn’t dispense a ton of serum, so you might need to use a few pumps (closer to three to five) if you have really thick or long hair.
Key Ingredients: Marula oil, camellia oil, argan oil, maize oil, procaxi oil | Size: 3.4 oz | Scented: Yes | Key Benefits: Adds shine, hydrates, tames frizz
Best for Curly Hair
Paul Mitchell Super Skinny Serum
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This serum helps speed up hair’s drying time.
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The pump can sometimes get jammed.
“The best hair serum for curly hair, in my opinion, is the Paul Mitchell Super Skinny Serum,” says hairstylist and Arey co-founder, Jay Small. “This product has the ability to fill in gaps in the hair strand, smooth the cuticle, and protect curls from humidity — and a little goes a long way.” This product also does a great job of taming frizz, ultimately helping to define curls.
Another impressive feature? It actually speeds up drying time, so hair experiences less heat damage overall. “I apply it to wet hair when air-styling natural curls (or after towel drying) to smooth curly hair,” explains Small. Aside from making curls look their best, this serum also makes them smell their best, too. Every time you apply this oil, you’ll notice hints of apples, berries, and sweet florals. The results speak for themselves, but the packaging could use a refresh: The pump has a tendency to get jammed, so you may need to unscrew the top and pour the serum into your hands after a few months.
Key Ingredients: Dimethiconol, cyclopentasiloxane | Size: 5.1 oz | Scented: Yes | Key Benefits: Adds shine, tames frizz, decreases drying time
Best for Textured Hair
Adwoa Baomint Protect & Shine Oil Blend
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This serum is made with more than 15 natural oils.
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Though refreshing, the scent is very strong and lingers like a perfume.
If you’re looking for a product that’ll bring your hair back to life, we have just the thing you need. This Adwoa bestseller is made with an innovative blend of powerhouse ingredients including soybean, grape seed, olive, and sweet almond oils, as well as pomegranate, spearmint, and prickly pear, which work together to make hair healthier, stronger, and more nourished. These nutritious ingredients also promote hair growth, add shine, and tame frizz. Plus, you can use this product as a finisher after styling hair or as a hot oil treatment if your strands really need some love.
“Formulated specifically for dry, textured hair, this serum promotes moisture and shine and is lightweight enough for daily use,” says Donovan. “It incorporates more than 15 oils and smells refreshing. It’s also promoted for head-to-toe use and can be used on the body!” Pro tip: Apply a light layer to extra dry areas, like cuticles, elbows, and knees.
While we adore the fresh fruity fragrance, it is very strong. So if you’re sensitive to scent, you may want to skip this.
Key Ingredients: Soybean oil, grape seed oil, olive oil, sweet almond oil | Size: 3.3 oz. | Scented: Yes | Key Benefits: Adds shine, hydrates, strengthens, promotes growth
Best for Damaged Hair
Olaplex Bonding Oil
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This hair oil enhances color vibrancy.
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It can weigh down fine hair if it is applied too close to the root.
There’s no other way to say it: This Olaplex favorite is like liquid gold. For starters, it works well on all hair types and textures, adding noticeable glossiness and hydration. On top of that, it also provides long-term benefits for the hair since it’s made with the brand's signature ingredient – bis-aminopropyl diglycol dimaleate – which is essentially a molecule that helps bond the hair's structure back together (read: Less frizz and split ends). Additionally, this oil adds vibrancy to hair color, overall making strands look healthier and shiner. Last but not least, it also protects hair from heat damage and temperatures up to 450 degrees Fahrenheit.
To get the best results from this oil, add a few drops to wet or dry hair before using a straightener, curling iron, or blow dryer. (Personally, I like to warm this liquid in my hands before applying it to my hair. I will say that as someone with fine hair, I really only use this product on my ends because it can sometimes weigh down my strands if I put it too close to my roots.) As for the cherry on top, this small but mighty bottle is designed to dispense a limited amount of product, which means you’ll never have to worry about too much coming out.
Key Ingredients: Bis-aminopropyl diglycol dimaleate, grape seed oil, sunflower seed oil | Size: 1 oz. | Scented: No | Key Benefits: Adds shine, strengthens, provides heat protection
Best for Dry Hair
Reverie Leave-In Nourishing Treatment
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This serum is made with a blend of 16 essential oils that work together to effectively hydrate hair.
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This serum can weigh down curls.
“The best hair serum for dry hair is the Reverie Milk Anti-Frizz Leave-In Nourishing Treatment,” says Small. “Typically, serums sit on the exterior surface of the hair strand, leaving a build-up on the hair, but this product works well to help retain moisture.”
Thanks to a complex blend of oils (including pracaxi seed, ginger root, rose flower, clove bud, and jasmine flower oils, among others), this serum works overtime, nourishing strands by holding onto moisture and locking it in. By doing so, this product also reduces the appearance of frizz and flyaways over time.
“The serum is also highly absorbent and can be applied to both wet and dry hair,” Small adds. And, because it’s so absorbent, it can be used multiple times a day for added hydration. We also adore the dreamy, fresh fragrance that revitalizes your senses as it soaks in. However, we will note that this product can weigh down curls, so be sure to use it sparingly if you have curly hair. (One to two pumps should be ideal.)
Key Ingredients: Pracaxi seed oil, shea nut butter, ginger root oil, rose flower oil | Size: 3.3 oz. | Scented: Yes | Key Benefits: Hydrates, smoothes, tames frizz
Best for Frizz
Living Proof No Frizz Smooth Styling Serum
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This lightweight serum keeps hair smooth and frizz-free for up to 96 hours.
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Using too much can make hair look greasy.
You can kiss frizz goodbye (really!) when you smooth this styling serum into your strands. Crafted by biotech scientists, the lightweight formula smoothes out each hair follicle and actually repels humidity with a proprietary smoothing technology.
All you need to do is apply the silky serum (which also lightly hydrates and adds shine) to damp hair and blow dry for a sleek style that lasts for up to 96 hours. You may be tempted to douse your hair in the serum after seeing results, but applying too much can actually make hair greasy. Stick to one to two pumps for the best results.
Key Ingredients: Proprietary smoothing technology, humectant polymer | Size: 1.7 oz. | Scented: Yes | Key Benefits: Reduces frizz, adds shine, lightly hydrates
Best for Thinning Hair
The Ordinary Multi-Peptide Serum
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Caffeine and castor oil work together to increase blood flow to the hair follicles, thus promoting hair growth.
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This oil has a weird smell that some people don’t like.
The Ordinary knows a thing or two about hair care, and this serum proves it. Made with a mix of caffeine, peptides, castor oil, and lactic acid, the formula works to promote hair growth by stimulating the scalp and increasing blood flow to the hair follicles. Plus, it makes hair look fuller after each use, thanks to the addition of xanthan gum, which clings onto hair strands and makes them appear thicker.
It does more than promote hair growth, though. The all-in-one serum also smoothes hair and makes it more manageable thanks to butylene glycol, which acts as a conditioning agent and increases moisture retention. For the best results, apply a few drops of this serum to a clean scalp. (It’s recommended to use it before bed.) Then, massage it in. Since this oil is essentially a leave-on treatment, don’t wash it out until morning. If the smell starts to bother you (it isn’t the most pleasant) washing it out after two or three hours will still give you noteworthy results.
Key Ingredients: Caffeine, peptides, castor oil | Size: 1 oz. | Scented: Yes | Key Benefits: Hydrates, thickens, smoothes
Best for Hair Growth
Nécessaire The Scalp Serum
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This serum is hypoallergenic and non-comedogenic, which means it’s safe for the scalp and won’t clog pores.
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It takes about 90 days to see results.
Though Nécessaire is known for its bath and body products, its hair care also deserves recognition. This scalp serum, in particular, stands out for its ability to make hair thicker, fuller, and lusher. Made with a five-percent biomimetic peptide blend that makes hair both healthier and stronger, as well as hyaluronic acid, the nourishing serum transforms the ecosystem of the scalp, hydrating and nourishing it and promoting hair growth. Plus, niacinamide supports the scalp's overall protective barrier.
Aside from its game-changing ingredients, this serum is super lightweight and easily absorbs into strands. It’s also color- and keratin-safe as well as hypoallergenic and non-comedogenic. Not to mention, it’s vegan, gluten- and cruelty-free, and comes in recyclable packaging. We will note that it’ll take about 90 days for you to see new hair growth appear, so just use it religiously and your patience will pay off big time.
Key Ingredients: Peptides, hyaluronic acid, niacinamide | Size: 2 oz | Scented: No | Key Benefits: Hydrates, thickens
Best for Flaky Scalps
MFLORENS No. 1 Scalp Serum for Hair
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This hair serum is infused with over 50 botanicals.
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It’s recommended to wash this serum out after 30 minutes, so you won’t want to use this if you’re in a hurry.
“For flaky scalps, hands down my favorite serum is MFLORENS No. 1 Exfoliate & Revitalize Scalp and Hair Serum,” says celebrity colorist Bianca Hillier, whose clients include Becky G, influencer and model Rocky Barnes, and comedian Lauren Lapkus. “Not all serums are supposed to be applied to the scalp, but in this case, this product has been created for scalp health, delivering extremely natural ingredients and nutrients to the scalp and strands.”
And, the term ‘extremely natural ingredients’ is right – this serum is made with over 50 botanicals, including flowers, trees, fruits, vegetables, and herbs. It works by gently exfoliating the scalp, removing everything from product build-up to dead skin. Then, it nourishes the scalp, adding deep hydration and fortifying vitamins. To get the most out of it, be sure to massage it deeply into your head. Just note that the brand recommends washing it out after 30 minutes (although you can leave it in for up to four hours), but be sure to rinse it out before going to sleep.
Key Ingredients: Castor oil, grape seed oil, rosemary, eucalyptus | Size: 2 oz | Scented: Yes | Key Benefits: Exfoliates, strengthens, hydrates
What to Keep in Mind
Hair Type
“When buying a hair serum, you should consider what issue you would like that serum to fix, along with what type of hair you have,” explains Small. “Every time I work with a client, I evaluate their [hair’s] texture, density, and lifestyle – each of these will need to be factored in when choosing the best product for each person.” By determining what hair concern you’re aiming to address (dryness, breakage, frizz, etc.) as well as knowing your hair’s texture (fine, medium, or thick), you’ll be able to find a serum that doesn’t weigh down your strands.
To give you a better understanding of how this relates to each hair concern and hair texture, Donovan notes, “Lightweight serums [like Kristin Ess Weightless Shine Working Serum, Moroccanoil Moroccanoil Treatment Light Hair Oil, Adwoa Baomint Protect & Shine Oil Blend, or Living Proof No Frizz Vanishing Oil] are best for fine hair and/or adding shine so as not to weigh hair down."
"If you have thick or curly hair, a heavier serum [like Kérastase Elixir Ultime Hydrating Hair Oil Serum or Paul Mitchell Super Skinny Serum] can help in taming frizz," Donovan adds. "And, if you are seeking a serum to help with hair health and volume, you will want to seek out another type of serum entirely – one that addresses scalp health as well as hair appearance [such as Nécessaire The Scalp Serum with 5% Biomimetic Peptide Blend For Hair Growth or The Ordinary Multi-Peptide Serum For Hair Density].”
Ingredients
When choosing a hair serum, it’s important to take a look at the ingredient list to know if the product is safe for your strands. Some ingredients like sulfates, mineral oil, and parabens can dry out hair, causing breakage down the line. To avoid this, it’s equally important to know what ingredients to look for, aside from just what to avoid
“I personally love a serum with hair vitamins and peptides (like vitamins B3 and E, copper, peptides, and tripeptides) for thicker-looking hair and a healthy scalp,” says Donovan. “An oil – coconut, argan, or moringa – will keep hair hydrated and smooth. Also, make sure your serum contains some form of antioxidants to help protect from environmental damage.” These antioxidants can include vitamin C (spoiler: It’s not just good for your face!) as well as selenium and polyphenols.
Frequency of Use
Wondering how often you can use your favorite hair serum? “Daily!” says Donovan. “The right hair serum can help protect your hair from damage caused by heat styling, environmental factors, and even detangling or tension caused by too-tight hairstyles.”
However, if you have fine hair and don’t want to use hair serum every day, you can change your frequency to better fit your needs. “Anytime you wash your hair or are going to apply heat to your hair is a great time to use a hair serum for protection,” says Hillier.
Your Questions, Answered
What is hair serum?
“Traditionally, a hair serum is a product that helps to smooth, tame, and protect hair from styling or environmental damage,” explains Small. “Serums are liquid-based formulations that contain ingredients that absorb into and coat the hair strand, helping to enhance density and control frizz. Serums have now evolved and are being used on the scalp to help with hair growth and pigment, too.”
How do you use hair serum?
“Hair serums can be used on both wet or dry hair,” says Small. “If applying to wet hair, I would always start with less product than you think you need – once hair has dried, you can add more if necessary. If hair has dried and still has frizz, I would apply a small amount from mid-shaft to ends, working away from the scalp.”
Generally, the rule of thumb is to use a nickel-size amount of product. From there, apply it to the tips of your hair and work your way up to the mid-shaft and root.
Are hair serums good for hair?
Yes, hair serums are good for hair. “Hair serums are a great way to protect your hair from heat, frizz, and environmental pollutants while giving you a beautiful style that will not weigh the hair down,” says Hillier. “Some serums will even have a flexible hold for a longer-lasting blowout.” For best results, be sure you’re using the right serum for your hair type.
Why Shop With Us
Lauren Harano has over seven years of experience in the beauty industry, previously holding editorial positions at Cosmopolitan, Seventeen, POPSUGAR, and NBCUniversal; and writing beauty pieces for InStyle since August 2022. She is knowledgeable in skincare, makeup, and hair care, and has tested hundreds of products during her career. For this article, Lauren interviewed four hair experts: hairstylist and Arey co-founder, Jay Small; Director of Client Services at Barber Surgeons Guild, Alexia Donovan; and celebrity colorist Bianca Hillier. Each expert lent their expertise and shared their favorite hair serums for different hair types and textures. Additionally, Lauren researched top-rated products to find the best ones that can effectively nourish hair, add shine, and protect strands from breakage. Before making her final selections, Lauren looked at the reviews, key specs, and ingredient lists to narrow down which hair serums were both safe and effective.