Brittle hair, be gone! The best protein treatments deserve a permanent spot in your routine—especially if your strands are feeling limp, brittle, or dull. No, these powerhouse formulas aren’t your average smoothing hair masks.

First and foremost, it’s essential to understand hair from a scientific POV. “Hair strands are literal protein threads; once they protrude out of the hair follicle, it becomes a fine fabric,” as trichologist Bridgette Hill explained in our guide to repairing damaged hair. That said, protein treatments are formulated to target the structural integrity of your lengths, by filling in weak spots along the hair shaft and reinforcing its natural strength. Not to mention, they can also smooth frizzy flyaways, prevent split ends, and tackle dryness.

Think of them as necessary TLC for lengths that have seen one too many chemical treatments and daily heat styling. The benefits of protein treatments accumulate with each use, transforming hair from fragile to fortified with consistent use (and yes, that means shinier and softer lengths, too). Unsurprisingly, protein treatments are also a specialized area of Korean haircare, having long been popular in Seoul, and only just gaining buzz stateside. Their popularity is largely due in part to K-beauty’s innovative approach to formulas, or as Landing International CEO Sarah Chung Park explained, “the same clinical rigor, layered actives, and fermentation technology that transformed the global skin-care world.”

Ahead, 9 Vogue-approved protein treatments worth weaving into your routine (and your compromised hair strands).

Best Overall: K18 Leave-In Molecular Repair Hair Mask

• Why We Love It: K18’s TikTok-famous hair mask is a Vogue editor-favorite that works in just four minutes to repair damaged strands through a blend of peptides and proteins. It’s a go-to of celebrity colorist Travis Olgetree, for it’s noticeably transformative results. Fellow celebrity colorist Aura Friedman agrees, adding that this pick keeps hair shinier and more manageable after consistent use. “The formula of this mask is essentially the molecular copy of the 18 peptides that make up keratin. This also lowers the pH of the hair, which keeps the cuticles tight, and maintains both color molecules and moisture. The results mean hair is shinier and more manageable,” Friedman previously told Vogue.
• Editor’s Experience: “One of my all-time favorite deep conditioning treatments, this has been in regular rotation in my hair-care routine for the past year and a half. I have very high porosity hair, I’m no stranger to using heat tools, and I’ve also spent many years experimenting with color. While I’m now loyal to my natural color, but can’t seem to put down my Dyson AirWrap, this lightweight mask makes my hair feel soft to the touch and heat-protected. Plus, I absolutely love that it’s a leave-in, because I hate having to dissociate in the shower while waiting for a traditional hair mask to run its course.” —Conçetta Ciarlo, beauty shopping writer
• Key Ingredients: K18Peptide, hydrolyzed wheat protein, wheat starch
• Type: Leave-in mask
• Texture: Lightweight lotion
• How to Use: Skip conditioner, after shampooing—then apply to freshly wash lengths. Wait four minutes before brushing, drying or styling. No rinsing required!
• More to Know: Cruelty-free, sulfate-free, safe for color treated hair
• Size: 0.5 oz, 1.7 oz

Best with Biotin: Briogeo Don’t Despair, Repair! Deep Conditioning Hair Mask

• Why We Love It: Celebrity hairstylist Bridget Brager describes this protein-rich hair mask as “a great deep-conditioning mask that works to lock in moisture and improve shine.” Free of sulfates, silicones, and parabens, this seeks to repair signs of damage across all hair types and textures. The formula is also loaded with rosehip oil, algae extract, almond oil, biotin and B vitamins to nourish strands and add shine. “This celebrated product offers the best of both worlds, combining strengthening proteins with rich moisturizers,” celebrity hairstyling Davey Matthew previously told Vogue. “It’s a great option for someone looking to boost and maintain their hair’s health.”
• Editor’s Experience: “If anyone ever asks me for a reliable hair mask, this one is my first recommendation. True to its name, it delivers moisture and repair to all hair types. There’s no reason not to love it.” —Kiana Murden, beauty shopping editor
• Key Ingredients: Rosehip oil, algae extract, almond oil, biotin, avocado oil, hydrolyzed corn and soy protein
• Type: Rinse-out hair mask
• Texture: Rich cream
• How to Use: Apply to freshly shampooed hair from mid lengths to ends. Leave for 10 minutes before rinsing and repeat weekly.
• More To Know: Cruelty-free, sulfate-free, color-safe
• Size: 2 oz, 8 oz, 12 oz, 32 oz

Best for Fine Hair: Ouai Treatment Mask for Fine and Medium Hair

• Why We Love It: Fine hair needs TLC too, particularly from products that won’t weigh their hair down. Ouai’s mask does exactly that. “This is one of those tried-and-trusted products that you can turn to when you need instant results,” Hairstylist Justin Toves-Vincilione previously told Vogue, saying this pick’s ingredient list is heaven-sent. “It immediately penetrates the hair strands, propelling in shea butter, tamarind seed extract, and hydrolyzed keratin.”
• Key Ingredients: Hydrolyzed keratin, panthenol, shea butter, coconut water, ginger-root extract
• Type: Rinse out hair mask
• Texture: Creamy
• How to Use: After shampooing your hair, remove excess water from your lengths. Apply a quarter sized amount from ends to mid lengths. Rinse with cool water after five minutes.
• More to Know: Cruelty-free, color-safe, reef-safe
• Size: 8 oz

Best Affordable: Elizavecca Milky Piggy CER-100 Collagen Ceramide Coating Protein Treatment

• Why We Love It: Elizavecca’s protein-rich treatment the very first K-hair product that Michelle Lee, K-Beauty World CMO and former Allure EIC, tried. “The herbal extracts work alongside the silk amino acids to relieve stress and stimulate the scalp, improving hair elasticity and softness,” Lee told Vogue in our Korean hair masks guide. Plus, a blend of collagen, glycerin, and five protein types help to further hydrate and seal damaged hair cuticles—all while coming it at a wildly affordable price point. $7? What a steal!
• Editor’s Experience: “As my coworkers know, I hate spending money on hair care, so most of the shampoos and conditioners I use come from my fellow beauty colleagues at Vogue. But the one thing I will shell out on is the Elizavecca hair treatment. Luckily for me, it’s also very affordable and leaves your hair super soft and untangled. I love the whole line from Elizavecca, and I use their collagen spray on my hair afterward, which I’m convinced is why my hair grows so quickly. You can get it almost anywhere these days (thank god!).”—Irene Kim, production and editorial associate
• Key Ingredients: Dimethicone, glycerin, hydrolyzed silk, hydrolyzed collagen, hydrolyzed keratin, oat kernel extract, hydrolyzed wheat protein, hydrolyzed soy protein, hydrolyzed corn protein
• Type: Rinse out treatment
• Texture: Lotion
• How to Use: Apply to clean, towel-dried hair, with special attention to mid-lengths and ends. Let the product sit for 5-20 minutes before rinsing out.
• More to Know: Free from sulfates, parabens, and mineral oils
• Size: 50 ml

Best for High-Shine: Color Wow Money Masque

• Why We Love It: If there’s one thing that celebrity hair stylist Chris Appleton is known for, it’s ultra shiny hair—and you can spot those luminous lengths on his celebrity clientele from Christina Aguilera to Kim Kardashian. His collaboration with Color Wow delivered a mask that maximizes shine with a unique texture. Unlike other deep conditioning masks, this one has a featherlight, gel-like feel that won’t weigh down hair follicles. A powerful blend of blue sea kale, kelp, algae, and a hydrolyzed vegetable protein complex work together here to nourish even the most chemically processed hair. “This mask is a great option if your hair is feeling dull,” hair stylist Raven Hurtado told Vogue. “It provides shine, strengthens hair, and helps moisturize a dry and flaky scalp. It also works on all hair types to create healthy, shiny hair.”
• Editor’s Experience: “I’m a big fan of Color Wow’s shine-boosting products, from the heat protectant to this mask, they all help to fake an at home gloss. This was a long-standing go-to of mine when my hair was longer, for the instantly shinier results it imparts. I particularly like its gel-like texture that doesn’t feel heavy when applied. And yes, I like it enough to break my rule of hating waiting for rinse-out hair masks to set.” —Conçetta Ciarlo, beauty shopping writer
• Key Ingredients: Blue sea kale, sea kelp, algae, hydrolyzed vegetable protein complex
• Type: Rinse out hair mask
• Texture: Whipped, gel-cream
• How to Use: Apply the mask generously to freshly shampooed hair from mid-lengths to ends. Comb through to distribute evenly, and let sit for five to 20 minutes before rinsing.
• More to Know: color-safe, cruelty-free
• Size: 7.5 oz

Best with Keratin: Unove Deep Damage Repair Hair Mask

• Why We Love It: Unove’s Deep Damage Treatment K-hair treatment is a pick that Lee and Chung Park spotlight as a favorite in Seoul. Now, it’s becoming increasingly popular on Western beauty shelves. The treatment mask delivers a concentrated blend of keratin, hydrolyzed plant-based proteins, and conditioning ingredients to smooth and seal the cuticles of compromised strands.
• Key Ingredients: Glycerin, tocopheryl acetate, hydrolyzed silk, silk amino acids, hydrolyzed keratin, olive fruit oil, sunflower seed oil, hydrolyzed corn protein, hydrolyzed wheat protein, hydrolyzed soy protein
• Type: Rinse out treatment
• Texture: Rich gel-cream
• How to Use: Apply a quarter-sized amount to freshly washed, towel-dried hair. Avoid the scalp, focusing only on the mid-lengths and ends. Rinse thoroughly after one to three minutes.
• More to Know: Cruelty-free, paraben-free, phthalates-free
• Size: 7.5 oz

Best Bio-Identical Keratin: Virtue Restorative Treatment Mask

• Why We Love It: As with all Virtue products, their signature signature ingredient: Alpha Keratin 60ku, a bio-identical keratin that helps fill in cracks in the hair cuticle. This super-rich treatment mask moisturizes, repairs, and boosts shine. Board-certified dermatologist Kristina Collins cosigns the formula, noting that regular use promotes healthier and stronger hair over time. The formula is particularly beneficial for colored or chemically treated hair.
• Key Ingredients: Alpha Keratin 60ku, brown algae extract, baobab seed oil, plant-based protein, artichoke leaf extract
• Type: Rinse out hair mask
• Texture: Dense cream
• How to Use: After shampooing, distribute the product evenly throughout the hair; let it sit for two to three minutes before rinsing it out. The brand recommends using the product once a week.
• More to Know: Sulfate-free, color-safe, keratin-safe
• Size: 1.7 oz., 3.4 oz.

Best for Coily Hair: Cécred Reconstructing Treatment Mask

• Why We Love It: Clinically proven to repair damaged hair while enhancing shine and strength, Cécred’s formula is powered by its patent-pending Bioactive Keratin Ferment. Infused with scalp-nourishing antioxidants—like vitamin E—and a carefully curated blend of oils, it works to seal split cuticles and leave hair noticeably smoother, stronger, and radiant. Toves-Vincilione considers this pick ideal for weakened curls and coils. “Many people experience periods of limp and lifeless hair, whether it be from heat damage, relaxer damage, protein overload, or lightening processes. Cécred formulated this mask to get in there and get the job done with noticeable results after just one use,” he previously told Vogue.
• Editor’s Experience: “Beyoncé…Miss Tina…what did you put in this hair mask? Cécred’s Reconstructing formula is honestly incredible. Immediately after use, my hair feels stronger. Because of its ability to quickly transform damaged strands, it’s my go-to after braids or sew-ins when my hair is in desperate need of some tender care.” —K.M.
• Key ingredients: Bioactive keratin ferment, hydrolyzed rice, sea buckhorn oil, squalane
• Type: Rinse out hair mask
• Texture: Dense cream
• How to Use: After shampooing, distribute the product evenly throughout the hair; let it sit for up to 20 minutes before rinsing it out.
• More to Know: Cruelty-free, color-safe
• Size: 2.5 oz, 10 oz

Best for Over-Processed Hair: Healingbird Revive Protein Treatment

• Why We Love It: Another K-hair pick highly-recommended by Chung Park is Healingbird’s protein treatment. It’s especially good for anyone with heavily chemically-processed hair, because as explained in our best Korean hair masks guide, this treatment “simply out-proteins the competition.” That’s thanks to a blend of 30 proteins, 20 amino acids, and a dose of keratin that’s 5% of the overall formula. Conditioning and reparative, Chung Park noted that proteins from rice, corn, soy, potato, silk, and milk “target a different layer of damage simultaneously.”
• Key Ingredients: Amino acid blend, protein blend, hydrolyzed keratin, hydrolyzed silk, hydrolyzed vegetable protein, hydrolyzed corn protein, hydrolyzed soy protein hydrolyzed rice protein, argan oil, milk protein extract, hydrolyzed potato protein
• Type: Rinse out treatment
• Texture: Buttery
• How to Use: Apply to towel-dried, clean hair, leaving on for 3-10 minutes before rinsing thoroughly with lukewarm water.
• More to Know: Vegan, cruelty-free, sulfate-free, silicone-free
• Size: 200 ml