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Few things give away an overdue haircut faster than split ends, a.k.a. the scraggly strands that instantly make hair look rough and frizzy. The best split-end serums can make damaged hair look dramatically healthier, smoother, and shinier temporarily, though they won’t replace a fresh haircut (that’s the only true fix for frayed ends). “Once the strand has split and separated at the end, there's absolutely nothing that will bring it back together permanently,” says New Jersey-based stylist Michelle Cleveland.
Even though they may not be able to repair existing breakage and brittleness, split-end serums can still help “prevent more damage and further splitting of the hair,” says Los Angeles-based hairstylist Ashley Ruiz. “They help seal and coat the hair from UV heat and thermal styling.” So whether your frayed ends are the result of frequent heat styling, color appointments, rough brushing, or everyday wear and tear, these formulas are designed to smooth rough cuticles, soften brittle strands, and help minimize future breakage.
Our Top Split-End Serums
- Best Overall: Mise En Scene Perfect Serum, $19
- Best for Fine Hair: Roz Santa Lucia Styling Oil, $45
- Best In-Shower Treatment: Ouai Bond Repair Balm, $50
- Best Overnight Treatment: Innersense Overnight Repair Serum, $42
- Best Softening: Crown Affair Overnight Repair Serum, $58
Some split-end serums rely on lightweight silicones to temporarily seal and smooth frayed ends, while others are powered by nourishing oils that replenish lost moisture and boost shine. Stylists also recommend bond-building treatments to help strengthen weakened hair from within, as well as styling creams that double as heat protectants to defend against one of the biggest causes of split ends in the first place. Think of split-end serums as equal parts quick fix and preventative treatment: They won’t permanently repair a split end, but they can disguise existing damage while helping keep future fraying at bay. If your strands are rough, prone to breakage, or in need of some extra smoothing, these are the split-end serums truly worthy of a spot in your routine.
Frequently Asked QuestionsLargeChevron
- What is the biggest cause of split ends?
- Can you actually repair split ends?
- How can I make my split ends look better?
- Meet the experts
- How we test and review products
- Our staff and testers
Bottom line? No product can permanently repair your split ends, but these shine-boosting, heat-protecting formulas make them look significantly healthier until your next trim. Reach for one of these to help smooth current damage and prevent future damage.
Best Overall: Mise En Scene Perfect Serum
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Mise en Scene
Perfect Serum
Amazon
Olive Young
Allure commerce editor Sarah Han applying the Mise En Scene Perfect Serum
Sarah Han
Why we love it: Talk about a product that lives up to its name—Mise en Scène’s Perfect Serum is powered by Moroccan argan oil to hydrate and nourish dry, damaged strands and leave them silky, smooth, and dare we say almost perfect. What’s more: A blend of six more oils (including olive, coconut, and apricot) helps detangle, soften roughness, and minimize split ends. It doubles as a heat protectant up to 446 degrees Fahrenheit, so apply it after your shower to prep hair before styling. The light, fresh floral scent is a bonus, although it is also available in a rose-scented formula for those who want a more palpable aroma.
P.S. Other variations include the Watery Serum for thinner, easily weighed-down hair, and a Super Rich Serum for thicker, drier hair. There's something for everyone, which is why Mise en Scene's our top pick!
Han before applying the Mise En Scene Perfect Serum
Sarah Han
Han after applying the Mise En Scene Perfect Serum
Sarah Han
Tester feedback from commerce editor Sarah Han
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“My hair’s number-one enemy is frizz and split ends (your girl does not get regular trims—I know, I know), and this is the one product that’s helped the most with both woes. While it doesn’t calm every individual strand, it makes such a noticeable difference in the finish of my hair—it’s the closest I’ve ever felt to having ‘commercial-worthy’ hair. The original version, surprisingly, isn’t too heavy for my fine (but dense) hair and really boosts the shine of my brittle, damaged hair. I focus on my mids-to-ends, but with whatever leftover product I have, I’ll quickly smooth it over the top portion of my hair—avoiding the roots, of course.” —Sarah Han, commerce editor
More to know
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- Key ingredients: Moroccan argan oil, olive oil, coconut oil, apricot oil
- Who it’s for: all hair types
Best for Fine Hair: Roz Santa Lucia Styling Oil
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RÔZ
Santa Lucia Styling Oil
Amazon
Nordstrom
Sephora
Allure director of partnerships Meg Kernahan applying the Roz Santa Lucia Styling Oil
Meg Kernahan
Why we love it: Finding a split-end serum for fine hair is a balancing act—it needs to offer plenty of nourishment, but not leave it looking greasy. Roz’s Santa Lucia Styling Oil was practically made to pull this off (though it works just as well on other hair textures). The versatile formula can be used on wet or dry hair, according to Ruiz, who loves that it’s not too heavy on strands. It blends nourishing argan, olive, and jojoba oils with Roman chamomile to soften brittle ends, smooth cuticles, and add healthy-looking shine without flattening or weighing down strands. Beyond considering it a split-end helper, it’s also a styling staple in its own right: A few drops also tame flyaways, reduce frizz, and provide heat protection up to 450 degrees Fahrenheit. Despite being an oil, it absorbs quickly into the hair. Oh, and if all that wasn’t enough, it’s also a 2022 Best of Beauty Award winner.
Kernahan before applying the Roz Santa Lucia Styling Oil
Meg Kernahan
Kernahan after applying the Roz Santa Lucia Styling Oil
Meg Kernahan
Tester feedback from partnerships director Meg Kernahan
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“This hair oil has become my ride or die! Just a pump or two leaves my wavy hair looking shiny and frizz-free without it looking greasy. I usually run it through my wet hair after I shower, and then use another pump before I style my hair with heat for added protection and shine. It works great for a blow-out and on air-dried hair. I love the lightly floral and citrus scent—it is so bright and sophisticated.” —Meg Kernahan, partnerships director
More to know
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- Key ingredients: argan, olive, and jojoba oils, Roman chamomile
- Who it’s for: all hair types
Best for Shine: Crown Affair Overnight Repair Serum
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Crown Affair
Overnight Repair Serum
Sephora
Allure senior commerce director Shanna Shipin applying the Crown Affair Overnight Repair Serum
Shanna Shipin
Why we love it: Crown Affair’s Overnight Repair Serum is a reset button for hair that looks and feels dull and brittle. The lightweight, quick-absorbing formula packs a punch with a blend of flaxseed and chia for repair, plus the brand’s Tsubaki Meadow blend—it features meadowfoam seed oil and camellia-derived tsubaki—to seal in hydration; even so you don’t have to worry about waking up with greasy hair. Together, these ingredients give your strands the nutrients they need, leaving them stronger, softer, and shinier by morning (no rinse necessary!). Pro tip: Even though it's meant for overnight use, we've found that it works just as well as a smoothing serum during the day, too.
Shipin before applying the Crown Affair Overnight Repair Serum
Shanna Shipin
Shipin after applying the Crown Affair Overnight Repair Serum
Shanna Shipin
Tester feedback from senior commerce director Shanna Shipin
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“I put my hair through the wringer—curly one day, blown out the next—so this serum is a lifesaver. It's weightless, leaves no residue on your fingers, and dries down quickly. No staining your pillowcase or getting hair mask on your cheeks. It's meant to be an overnight serum, but I love using it in the daytime, too, essentially whenever I'm brushing my hair smooth—it seals up my split ends so well! On top of all the benefits I see from using this serum, it also has the signature Crown Affair scent; a revelation for damaged ends.” —Shanna Shipin, senior commerce director
More to know
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- Key ingredients: flaxseed, chia seed, Tsubaki Meadow blend, rosemary
- Who it’s for: all hair types
Best In-Shower Treatment: Ouai Bond Repair Balm
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Ouai
Bond Repair Balm
Amazon
Ulta Beauty
Sephora
Why we love it: Whether your hair’s damage is the result of bleaching, hair color, heat styling, or all of the above, Ouai’s Bond Repair Balm offers a more intensive approach than your average hair mask. Designed to be used in the shower after shampooing and to replace conditioner, the treatment works in just three minutes to help repair broken bonds, strengthen weakened strands, and improve elasticity from the inside out. Powered by vegan silk protein, hyaluronic acid, and peptides from hydrolyzed rice protein, it helps repair dry and damaged hair. Ruiz is a fan, noting it’s “quick and effective” at repairing and sealing ends. Use it every wash for the first few washes, then use just as needed moving forward.
Allure senior director of creative programming and development Natalie Campbell applying the Ouai Bond Repair Balm
Natalie Campbell
Campbell after applying the Ouai Bond Repair Balm
Natalie Campbell
Tester feedback from senior director of creative programming and development Natalie Campbell
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“This product is now a staple within my wash day routine. My hair tends to skew frizzy and is prone to breakage due to color treatment. I noticed a difference in my hair’s consistency post my first wash and a continuous improvement in hair strength after multiple washes. The product really helps create an overall smoother look for my natural hair, and then lessens my need for other products for styling. I am already on my third bottle!” —Natalie Campbell, senior director of creative programming and development
More to know
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- Key ingredients: vegan silk protein, hyaluronic acid, peptides from hydrolyzed rice protein
- Who it’s for: damaged hair
Best for Frizz: Bumble and Bumble Hairdresser's Invisible Oil Long Last Styling Cream
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Bumble and Bumble
Hairdresser's Invisible Oil Long Last Styling Cream
Amazon
Nordstrom
Ulta Beauty
Former Allure commerce writer Lily Wohlner applying the Bumble and Bumble Hairdresser’s Invisible Oil Long Last Styling Cream
Lily Wohlner
Why we love it: Bumble and Bumble’s Hairdresser’s Invisible Oil Hair Styling Cream can turn a bad hair day into a spectacular one with just one pump. Packed with six nourishing oils—think coconut, argan, grapeseed, nangai, and more—that soften and smooth even the frizziest of strands, it gets to work on any and all flyaways. The lightweight formula won’t weigh down fine strands, but it’s still rich enough to hydrate thicker, curlier, or drier hair types and really tamp down errant hairs. Apply it to damp hair, style to your liking (it protects against heat up to 450 degrees!), and cue the silky, split end-free finish. And, if you’re into fruity-floral scents, you’ll love this cream even more.
Wohlner before applying the Bumble and Bumble Hairdresser’s Invisible Oil Long Last Styling Cream
Lily Wohlner
Wohlner after applying the Bumble and Bumble Hairdresser’s Invisible Oil Long Last Styling Cream and heat styling
Lily Wohlner
Tester feedback from former commerce writer Lily Wohlner
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“My hair is on the finer side, so I can tell immediately when a product is too heavy. This cream, though, is always featherlight. It never weighs my strands down (hello, volume!), but still delivers on moisture and hydration. It’s also a powerhouse when it comes to fighting frizz and humidity in the summer, which my hair is always in dire need of. Think of it as a frizz-fighting styling cream and smoothing hair oil rolled into one.” —Lily Wohlner, former commerce writer
More to know
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- Key ingredients: Coconut oil, argan oil, grapeseed oil, nangai oil
- Who it’s for: those with thick, frizzy hair
Best for Color-Treated Hair: Innersense Overnight Repair Serum
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Innersense
Overnight Repair Serum
Ulta Beauty
Credo Beauty
Han applying the Innersense Overnight Repair Serum
Sarah Han
Why we love it: No time for an in-shower mask? Let your split-end serum do the heavy lifting while you get your beauty sleep. Innersense’s Overnight Repair Serum is a no-rinse treatment that works overnight, helping repair weakened bonds, smooth rough cuticles, treat split ends, and lock in moisture so you wake up with softer, healthier-looking hair. Powered by hydrolyzed moringa olfeira seed protein, this naturally derived bond-building ingredient penetrates the hair’s strand and actually removes cysteic acid, which is formed when bonds break during chemical treatments and is a sign of hair damage. Alongside the hydrolyzed moringa olfeira seed protein, tamanu oil locks in moisture and lavandin extract adds shine, making the lightweight gel-serum a serious multitasker. And if you’re concerned about greasy residue, no need to worry—the formula is designed not to transfer to your pillow, so it couldn’t be easier to use while you sleep.
Han before applying the Innersense Overnight Repair Serum
Sarah Han
Han after applying the Innersense Overnight Repair Serum
Sarah Han
Tester feedback from Han
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“My hair is dry and frizzy to begin with, but when you add bleach/color and factor in infrequent haircuts (sorry!), it’s a recipe for pronounced split ends. I use an in-shower hair mask once in a while—when I find myself patient enough to spend an extra 10 minutes in the shower, which is rare—which is why I love leave-in serums like this Innersense Overnight Repair Serum. (Hello, lazy girl approved!) After I rough-dry my hair to about 85%, I take run two pumps of the gel serum through my mid-lengths to ends, really massaging it into the latter. I wake up with noticeably softer, smoother hair and ends, and it’s a breeze to brush/manage/style. When I air-dry it with other products, my hair often becomes poofy the next morning, and there’s nothing like that with this serum. Bonus: Thanks to the lavender, it smells so relaxing (as all Innersense products do) and makes me extra ready for bed.” —Sarah Han, commerce editor
More to know
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- Key ingredients: hydrolyzed moringa olfeira seed protein, tamanu oil, lavandin extract
- Who it’s for: all hair types
Best for Thick Hair: K18 Molecular Repair Hair Oil
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K18
Molecular Repair Hair Oil
Amazon
Sephora
Shipin applying K18 Molecular Repair Hair Oil
Shanna Shipin
Why we love it: New York City-based hairstylist and colorist Lazaro Lambertucci says the K18 Molecular Repair Hair Oil is “weightless and amazing for all hair types,” and our editors fully agree. Just one pump (add more as you see fit if you have thicker hair) of the deep-conditioning blend of squalane, avocado oil, and sunflower oil smooths the look of splitting ends, frizzy hair, and flyaways while preventing heat-related hair damage at up to 450 degrees Fahrenheit. It also contains a blend of peptides that support and condition the hair shaft for a stronger feel and glossier finish. No wonder it's a 2023 Allure Best of Beauty Award winner.
Tester feedback from Shipin
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“My poor curly hair—after many years of continued heat-styling, it needs hair oil like it needs hydration. Which is to say: desperately! But because my hair is low porosity, I find that so many oils just sit on the top of the shaft—rather than penetrate the hair. K18, however, continues to prove itself as a mainstay in my routine, because this oil is simply built different. Not only does it leave your hair with a natural-looking shine, but it restores life, luster, and bounce. It's a K18 product, so of course it's going to repair the hair while tamping down on damage-induced frizz! A word of caution: A little goes a long, long way! It'll take trial and error, but I would not recommend overusing the product, otherwise, you will be left with greasy-looking strands. If you have finer hair, one drop could truly be all you need for your whole head; for my thick hair, I use two, sometimes three—but that's it! When I use it along with the K18 Leave-In? Compliments galore!” —Shanna Shipin, senior commerce director
More to know
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- Key ingredients: squalane, avocado oil, sunflower oil, peptides
- Who it's for: all hair types
Best for Shine: Kérastase Nutri Supplement Split-Ends Serum
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Kérastase
Nutri Supplement Split-Ends Serum
Amazon
Sephora
Why we love it: An antioxidant-infused hair oil made for all hair types, the Kérastase Nutritive Split Ends Serum injects life into dull strands. This conditioning treatment's star ingredient is niacinamide, also known as vitamin B3, which is known for its moisturizing and shine-boosting properties that'll have your hair feeling smoother and softer than ever. “It can also help support hair health by slowing shedding and providing antioxidant protection,” Chicago-based dermatologist Omer Ibrahim, MD, previously told Allure. To top things off, this formula features plant-based proteins, which retain moisture and nourish hair for that high-shine, just-left-the-salon finish.
More to know
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- Key ingredients: niacinamide, plant proteins
- Who it's for: any hair type looking to repair damage and restore shine
Frequently Asked Questions
What is the biggest cause of split ends?
If you’re dealing with split ends, your hot tools are likely the first to blame. (Sorry!) While chemical treatments, environmental stressors, extended time between haircuts, and rough brushing can all contribute to split ends, “the biggest cause of split ends is thermal styling, blow-drying and the constant use of hot tools,” Ruiz says. That’s why using split-end serums, leave-in conditioners, and heat protectants is so important to protect hair while styling, she adds.
While no product can permanently mend a split end once it forms, it’s possible to prevent them. Start by using products that offer heat protection alongside nourishing ingredients (and remembering to use a heat protectant every single time you reach for a blow-dryer, curling iron, or flat iron). That can keep your ends looking healthier for a longer time in between trims.
Can you actually repair split ends?
For hair that's already in Splitsville, it may be too late to actually fix the hair strand, but that doesn't mean you can't help improve how your hair looks. "Any product on the market for split-end repair is targeted more to the appearance of split ends," says Cleveland. Translation: It makes them less noticeable by giving the hair a sleeker, healthier look. The only true fix for split ends is snipping them off right at the start of the split.
How can I make my split ends look better?
Luckily, there are steps you can take to prevent split ends, according to Campos. "Little trims keep your hair shaft healthy and from continuing to split," she tells Allure, urging those reluctant to let scissors near their hair to take a chance on taking off the last inch or two every now and then.
If you absolutely refuse to get a trim (and even if you don't), you can help prevent fraying by brushing correctly when you're detangling strands. "Remember to start from the bottom and work your way up slowly," she says.
Another rule of thumb: Reduce how often you use heated styling tools in your hair-care routine, as they can dry hair out and diminish its natural proteins.
Meet the experts
- Ashley Ruiz, a hairstylist at Flore Los Angeles
- Lazaro Lambertucci, a New York City-based hairstylist and colorist
- Matilde Campos, a Los Angeles-based hairstylist
- Michelle Cleveland, a New Jersey-based hair stylist
- Omer Ibrahim, MD, a Chicago-based dermatologist
How we test and review products
We always enlist a range of testers for our makeup vertical, but hair-care products and tools are another story. While certain products can be used across different hair textures, lengths, curl patterns, thicknesses, colors (natural and unnatural), and needs, hair products are often created with specific consumers in mind. Many are created to address a concern (dandruff, breakage, brittleness) or to work most effectively for a specific hair type (4C curls, wavy hair, gray hair). You wouldn’t want to pick up a purple shampoo that’s only been reviewed by someone with, say, auburn hair, or a diffuser that’s never been tested by anyone with curls — right?
For our review of the best split end treatments, we enlisted the help of multiple editors, writers, contributors, and hair stylists with varying hair types, concerns, and desired outcomes (i.e., want shinier hair). Testers considered performance across four primary categories: efficacy, texture and experience, fragrance, and packaging. For more on what's involved in our reporting, check out our complete reviews process and methodology page.
Our staff and testers
A beauty product is a personal purchase. You might be searching for a face cream to address persistent dryness or a new nail product to add to your Sunday self-care routine; you may simply be browsing around for the latest launches to hit the hair market. No matter what you seek or your individual needs and concerns, Allure wants to ensure that you love anything we recommend in our stories. We believe that having a diverse team of writers and editors — in addition to the wide range of outside testers and industry experts we regularly call upon — is essential to reaching that goal.
After all, can we really say a skin-care product is the “best” for people over 50 if the only testers we’ve solicited opinions from folks who have yet to hit 30? Can we honestly deem a high-end diffuser worthy of your hard-earned cash if it’s never been tested on curls? We’re proud that our staff spans a wide range of ages, skin tones, hair textures, genders, and backgrounds, which means that we are able to fairly assess any beauty product that comes into the beauty closet.
