Can Shampoo *Actually* Thicken Your Hair? We Asked 3 Experts

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As a beauty editor, working with celebrity hairstylists is all fun and games, until they so graciously tell you that you have some of the oiliest, finest hair they’ve ever worked on. Love that for lil ol’ me. Which is why my bathroom is now overflowing with hair-growth shampoos, volumizing hair products, scalp treatments, and even hair-growth vitamins (desperate times, okay?!), all in hopes of magically getting thicker, fuller hair. But the one product that’s surprisingly made the biggest difference? Hair-thickening shampoo. Stay with me.

Listen, no shampoo can make you grow longer hair or even thicker hair overnight. But hair-thickening shampoos can (1) moisturize and plump up your strands, leading to temporarily fuller-looking hair, and/or (2) break down scalp oils and product buildup that’s been making your hair look flat. But it took me lots of testing to find the formulas that actually worked for me, plus a bit of consulting with the experts—dermatologist Hysem Eldik, MD; trichologist Gretchen Friese; and hairstylist Andrés Melendez—to compile this full list of the best hair-thickening shampoos below. Lemme give you a peek:

✔️ P.S., This is new, up-to-date info, bb. We updated this article in July 2023 to add new hair-thickening shampoos our editors tested and loved, delete outdated oldies, and check in with new experts for the latest in hair loss and thinning, just for you.

Our top picks for the best thickening shampoos in 2023:

Keep reading for all of the best hair-thickening shampoos, as tested by moi (and two other Cosmo editors). Then, we’ll get into the nitty gritty, like does hair-thickening shampoo work and how to choose the right one for your needs.

Cleansing Volumizing Paste

Of everything I’ve tested to give me voluminous, Khloe-Kardashian hair, this hair-thickening shampoo does the best job at cleansing my scalp and giving my roots an ~oomph~. The formula is filled with a mix of exfoliating sugar crystals and Moroccan-lava clay—which soaks up the oils on my scalp and helps physically slough away buildup—turning the product into a paste rather than a creamy liquid.

I just scoop a dollop into my hand and quickly massage it together before smoothing it onto my scalp and massaging until it starts to foam. I’ll sometimes even buff a scalp massager in circular motions to really boost the lather and get the product into my roots. I spritz on a lightweight conditioner spray, rinse, and then load up on texturizing spray and blow dry—and I suddenly look like I have quadruple the number of hairs on my head. This stuff seriously gives my fine, oily hair a fluffy volume I never thought was possible.

• Key ingredients: Moroccan lava clay (soaks up oils and exfoliates), sugar crystals (exfoliates)

• Sulfate free? No

• Hair type: Oily/fine to normal hair

THE REVIEWS: According to a reviewer, “Adds more volume than any other product I've ever tried. Cleans hair really well but doesn't leave it dry or weighed down. I have thin, wavy, frizzy hair, for reference. You use a small amount, so it's a great value too.”

Peptide Prep Color-Safe Detox Clarifying Shampoo

Ever since I started shampooing with this once or twice a week, I’ve gotten hella compliments on how full my hair looks. It uses a combo of physical exfoliators (see: charcoal) and chemical exfoliants (salicylic acid) to slough off the dead skin, oils, and product build-up on my scalp, which immediately lifts my roots and makes my hair feel and look a bit thicker. Plus, it’s filled with strengthening peptides that help restore the bonds in my hair to hopefully help it grow longer with time too.

• Key ingredients: Charcoal (exfoliating), salicylic acid, peptides

• Sulfate free? Yes

• Hair type: All* (*but might be drying for coarse or dry hair if used too often)

THE REVIEWS: One tester writes, “This stuff is a miracle. My hair was dry, frizzy, overprocessed and a mess. The first time I used it was such a dramatic improvement, that my husband who's oblivious to everything, noticed a difference. Shiny, manageable and healthy. Buy it, buy it, buy it!”

Lambdapil Hair Loss Shampoo

If you’re experiencing hair loss or thinning, first see a dermatologist (or try a telemed service, like Ro or Apostrophe) to get a good bill of health and determine the cause. But you should also make sure you’re washing your hair once a week or so with this anti-inflammatory-spiked formula from Isdin. Dermatologist Ife Rodney, MD, previously recommended this shampoo to Cosmo because it’s filled with niacinamide and zinc that may “help improve skin barrier function, which can potentially reduce inflammation that can lead to hair fall.” Just note it does contain sulfates, so if you have a drier hair type, limit your use to once a month and make sure to smooth on a deep conditioner afterward.

• Key ingredients: Niacinamide, zinc, hydrolyzed soy protein (strengthens)

• Sulfate free? No

• Hair type: “Normal,” fine

THE REVIEW: "So far, I’m really liking this shampoo,” one reviewer writes. “I guess I wasn’t expecting it to smell so good, but I love it. I also love the feeling of my hair after I use it. Just from a short use, I can see a difference in how my thin hair styles fuller. Something I haven’t found with other brands claiming to help thin hair.

Thickening Volume Shampoo

Contrary to the sulfates slander all over the internet, my ultra-oily roots love being sudsed up with this sulfate-filled shampoo once every two weeks to strip away product buildup and grease. I love that this formula isn’t chock-full of a bunch of heavy oils to try to offset the dryness (which ultimately just weighs my hair down), and instead uses a little aloe vera to help soothe irritation, along with panthenol to very-lightly hydrate. I just always follow it up with a moisturizing deep conditioner to give my ends some ~love~.

• Key ingredients: Sulfates (strong cleanser), aloe vera, panthenol

• Sulfate free? No

• Hair type: Fine, oily hair

THE REVIEWS: “I have medium-length. fine hair but quite a lot of it, so I find that typical shampoos eventually make my hair feel quite limp and it can get greasy/flat over the day. This shampoo has been amazing for my particular hair—it feels soft, manageable, voluminous and shiny."

Original Gold-Label Anti-Thinning Biotin Shampoo

Quickly search for hair-thickening shampoos on Amazon, and you’ll immediately be served up this biotin-spiked formula, thanks to its 20,700+ positive reviews. Testers rave about how soothing this shampoo feels on their scalp (hi, aloe vera, along with lactobacillus ferment, a calming probiotic), which helps create an ~optimal environment~ for healthy hair growth. And if you’re interested in the conditioner too, pick up this duo set, which also racked in a whopping 15,500+ five-star reviews.

• Key ingredients: Tea tree oil, aloe vera, lactobacillus ferment (probiotic)

• Sulfate free? Yes

• Hair type: All

THE REVIEWS: According to one tester, “This stuff is nothing short of miraculous. Within just a few weeks of use, I noticed a significant reduction in hair fall. My brush wasn't covered in strands of hair anymore, and I could run my fingers through my hair without feeling like I was losing half of it. This magical potion also thickened my hair. My once lackluster locks gained a newfound volume and bounce. It was like I had stepped out of a hair commercial every time I styled my hair.”

HoliRoots Hydrating Shampoo

If you want thicker, fuller hair but are afraid of a hair-thickening shampoo stripping away all of your moisture, lemme intro you to Fable and Mane’s HoliRoots Shampoo. It’s super frickin’ moisturizing (hello, coconut oil, sunflower-seed oil, murumuru-seed butter, and aloe vera—all of which make your hair look a little bit “plumper”) and uses only ultra-mild cleansers to clean your scalp. But my fav? It’s also formulated with centella asiatica, an anti-inflammatory extract that helps soothe irritation on your skin and scalp that could potentially stall hair growth.

• Key ingredients: Coconut oil, sunflower-seed oil, murumuru-seed butter, aloe vera, centella asiatica

• Sulfate free? Yes

• Hair type: “Normal,” coarse, dry, damaged hair

THE REVIEWS: “Loved this,” writes one reviewer. “It had a really pleasant scent to it. After use, my hair felt moisturized, smooth, and luscious. I would absolutely buy this product again.”

Saffron Rose Shampoo

If your thick or coarse hair tends to get weighed down and flat at your roots, try this moisturizing shampoo from Joon. It combines oils—camelina, pistachio, and argan oils—with a strong-ish surfactant to break down buildup on your scalp while sealing in moisture to offset dryness and irritation. And if you’re into a spa-like experience in the shower, you’ll love the sweet, pistachio-spiked scent of this shampoo—I’ve already emailed the brand to make an accompanying perfume because it smells so divine.

• Key ingredients: Argan oil, camelina oil, hydrolyzed pea protein (strengthening)

• Sulfate free? Yes* (*but contains other strong cleansers)

• Hair type: All* (*but some oily/fine hair types might have to pair with a weekly clarifier)

THE REVIEWS: One tester writes, “This is an absolutely beautiful shampoo! I recently discovered this, and my husband and I both love it! It’s luxurious, smells divine, lathers well, gently cleans my hair, and makes my hair silky and lovely. So happy!”

Thick & Full + Biotin & Collagen Volumizing Shampoo

Heat, bleach, chemical relaxers, mechanical damage—whatever hair sins you’ve committed in the past, trust that this hair-thickening shampoo will make your hair look and feel a little bit thicker and stronger. It actually helps repair some of the damage in your hair with strengthening hydrolyzed wheat proteins, which helps fill in all the little cracks in your hair strands. Biotin and hydrolyzed collagen also gently moisturize, making your hair feel softer and less brittle over time.

• Key ingredients: Biotin, hydrolyzed collagen, wheat proteins

• Sulfate free? Yes* (*but contains other strong surfactants)

• Hair type: All

THE REVIEWS: “It made my hair feel and smell so clean—it was extremely soft and felt really healthy after washing," reads one review.

Volu Shampoo

Cosmo associate editor Siena Gagliano swears by this hair-thickening shampoo from Davines for her long, super-fine hair. It uses a mix of light hydrators (sodium PCA, glycerin, and panthenol), along with a handful of medium-to-strong cleansers to break down oils and buildup on her scalp. “If I'm doing a style where I want lots of body, like beach waves or a classic blowout, I always wash with this shampoo first—it cleanses without adding any unwanted weight,” she says.

• Key ingredients: Sodium PCA, glycerin, panthenol

• Sulfate free? No* (*but contains other strong surfactants)

• Hair type: Oily-to-normal hair

THE REVIEWS: One review reads, “This is the best shampoo I’ve found yet. My hair was not flat, had volume, and felt amazing and has lasted me a few days now. I’m beyond happy.”

Briogeo Scalp Revival Charcoal + Coconut Oil Micro-exfoliating Scalp Scrub Shampoo

In order to have healthy hair-growth, you have to start from the root up, which is why you should def be incorporating this scalp-scrub/hair-thickening shampoo hybrid into your routine. Charcoal powder helps lift off dirt and product buildup (hi, dry shampoo!), while tea-tree oil acts as an antibacterial to help fight off zits and inflammation—all of which can potentially stunt hair growth. And as an added bonus, it’s also combined with a bunch of sealers to lock in moisture, like castor oil and coconut oil.

• Key ingredients: Charcoal (exfoliating), tea tree oil, castor oil, coconut oil

• Sulfate free? Yes

• Hair type: All

THE REVIEW: "WOW am I surprised,” reads one tester’s review. “I have a very sensitive scalp and my hair tends to get oily super fast...my hair/scalp feels clean and simply amazing!"

Thickening Shampoo

Where this hair-thickening shampoo stands out is actually all of the ingredients it doesn’t have. We’re talkin’ no synthetic fragrances, artificial colors, sulfates, or parabens (if you’re not into them). What it does have though? A blend of moisturizing biotin, aloe vera, rosemary oil, and vitamin E that help plump up your strands and make ‘em look a lil bit thicker.

• Key ingredients: Aloe vera, biotin, vitamin E, rosemary oil

• Sulfate free? Yes

• Hair type: All* (*might be too moisturizing for some extra-oily hair types)

THE REVIEW: "My hair is extremely fine and straight, I also have very sensitive skin, and I have had difficulty finding a shampoo that did not irritate my scalp or make my hair oily or flat. With this, so far my hair looks better and my scalp feels wonderful," reads one customer's review.

Volume Boost Anti-Dandruff Shampoo

Dealing with an itchy, dry scalp? Try this two-in-one hair thickening shampoo and conditioner duo. The formula kills dandruff with MVP-level antifungal pyrithione zinc, all while breaking down oils and product buildup that leads to limp hair with strong cleansers. FYI, though, it can be a bit drying, so limit use to once a week and coat your ends in a rich conditioner and leave-in product afterward.

• Key ingredients: Pyrithione zinc (kills dandruff), sulfates (breaks down oils)

• Sulfate free? No

• Hair type: Oily, "normal"

THE REVIEWS: “This smells so good, and it works wonders,” writes one reviewer. “Helps keep dandruff at bay and gives all-day volume!"

Shampoo for Magnificent Volume

This sulfate-free hair-thickening shampoo is filled with gentle cleansers that help lift away some dirt from your scalp without stripping your color with every wash. But it’s shockingly volumizing, thanks to a slew of polymers that expand the hair shaft, making each strand appear a little thicker, along with strengthening proteins that, over time, help reduce breakage.

• Key ingredients: Polymers (can make hair look slightly thicker), hydrolyzed vegetable protein (strengthening)

• Sulfate free? Yes

• Hair type: All

THE REVIEWS: “I have ultra-fine hair, and I have tried many, many products over the years—none have worked,” writes one reviewer. “Oribe hair products have been a miracle for me. My hair has never looked better!"

Sulfate-Free Volume Shampoo

This was the only shampoo I used for a year straight in college because it was inexpensive and made my thin hair look actually voluminous. It actually helps chemically exfoliate my scalp a little bit with salicylic acid, which dissolves some of the oils on my scalp that makes it look greasy and flat. Plus, it leaves my scalp lightly hydrated with some rosemary oil and vitamin E.

• Key ingredients: Salicylic acid, rosemary oil, vitamin E

• Sulfate free? Yes

• Hair type: Oily, "normal"

THE REVIEWS: “My hair is really silky, straight with no texture, so even though it's thick, it goes really flat without a good volumizing shampoo,” writes one tester. “I've tried so many, and this is my favorite by far in terms of performance. I don't think I have repurchased the same shampoo in years except for this one—it's the only one I buy now.”

Do hair thickening shampoos actually work?

Hair-thickening shampoos can’t make your hair grow or become denser, necessarily, because they cannot alter the chemical structure of the hair, and as a result, the thickness of the hair cannot be changed. Tbh, “the thickness of the hair most often is determined by the size of the hair follicle,” trichologist Gretchen Friese previously told Cosmo. If you really want to change the thickness—or regrow lost hair—you’ll need to see a dermatologist who can identify the cause and prescribe you a prescription-strength or in-office treatment plan unique to your hair loss situation.

However, thickening shampoo can give the illusion of thicker hair. Some formulas (like the Davines Volu Shampoo) can temporarily make your hair look fuller by using polymers or light hydrators that cling to your hair strands and make them swell and look thicker until you wash them out. Others (like the Cristophe Robin Cleansing Volumizing Paste) use physical and/or chemical exfoliants, as well as strong surfactants, to deeply clean your scalp, thus making your roots look lifted.

Why is my hair thinning?

Your hair might be thinning for a variety of reasons, most likely “a combination of genetics and hormonal changes that predispose your hair and scalp to a process called miniaturization,” says dermatologist Hysem Eldik, MD, “which involves your hair strands getting skinnier, thinner, and finer, eventually leading to fall out.” But it also can occur due to age, Friese previously told Cosmo. "As we age, the size and shape of the follicle changes and can shrink, which results in thinner hair,” she explained.

If you've recently undergone a stressful event (i.e., moving, stress, loss of a job, a breakup, etc.), or have an underlying medical issue (like a virus, vitamin deficiency, thyroid issue, anemia, or hormonal changes) and are noticing hair loss or thinning, you could be suffering from telogen effluvium—a form of temporary hair loss that can be reversed if the underlying issue is treated. Which is why it’s so important to see a dermatologist for a diagnosis, which leads us to…

When should I go to the doctor for thinning hair?

You should go to the doctor for thinning hair or loss as soon as you start to notice it, says Dr. Eldik. Hair loss can be a sign of an underlying condition that requires professional treatment, like hormones, stress, certain medications, and nutritional deficiencies (like low iron or zinc). Hair loss requires a holistic approach, which is where a dermatologist can come in to help, from prescription-strength medications and topicals to lifestyle habits and support.

How to choose the best hair-thickening shampoo:

Consider your goals

Are you just trying to make your hair look temporarily thicker or are you experiencing thinning and want to boost hair growth? "Thickening shampoos usually contain ingredients, like polymers, that wrap around each individual strand, thus giving the effect or feel of thicker or more dense hair," says hair colorist Andrés Melendez. In this case, try a formula like Oribe Shampoo for Magnificent Volume, which reviewers loved for thickening up their hair and adding volume to their roots.

But if you want to encourage hair growth or minimize shedding, look for anti-inflammatory ingredients, like the zinc and niacinamide in Isdin’s Lambdapil Hair-Loss Shampoo. They’ll help soothe irritation on your scalp, which can be a common cause for stagnant hair growth. Keep in mind: No shampoo alone will make your hair grow, but it can make your scalp healthier, which is a great place to start. You can also try a moisturizing and strengthening shampoo, like OGX’s Thick & Full + Biotin & Collagen Volumizing Shampoo, which will help repair damage and—hopefully, with time—reduce some hair fall.

Determine your moisture levels

If you have fine hair that’s prone to getting weighed down, opt for a clarifying shampoo like K18 Peptide Prep Clarifying Shampoo. It’ll help “break down buildup and oils that may be making your roots greasy and flat, giving it a much bouncier feel,” says Melendez. But if you have dry hair that just looks dull and limp, load up on moisture instead by choosing a rich shampoo that’s filled with sealing oils (Joon Saffron Rose Shampoo was a favorite amongst testers, fyi) to lock in moisture while still getting your roots gently clean.

Meet the experts:

• Hysem Eldik, MD, is a dermatologist at Marmur Medical in New York, NY, and assistant professor at Mount Sinai. Eldik specializes in general and cosmetic dermatology.

• Andrés Melendez is the lead colorist at The Knowlton in Bridgeport, CT, and a colorist at the Benjamin Salon in New York, NY. Melendez splits his time accommodating clientele along the East Coast, NY, CT, and FL.

• Gretchen Friese is a certified trichologist consultant at BosleyMD, and the salon director and hairstylist at Foushee Salon Spa in Littleton, CO. Friese recently spoke to Cosmo about hacks for fuller hair.

• Ife Rodney, MD, is a board-certified dermatologist in Fulton, MD, where she runs her own practice, Eternal Dermatology and Aesthetic Center. She specializes in hair loss and hair growth treatments and previously was interviewed about hair-growth shampoos.

Why trust 'Cosmopolitan'?

Beth Gillette is the beauty editor at Cosmopolitan, where she’s been writing about hair, skin, and nails for the past year, including curly hair products and dry-scalp treatments. In total, she has five years of experience researching, writing, and editing hair stories, which is how she’s become an expert in hair-thickening shampoos from trying legit hundreds of shampoos on her baby-fine, ultra-oily hair. Plus, she’s constantly interviewing dermatologists and hairstylists on hair-thickening shampoo formulas (tbh, selfishly).

Siena Gagliano is an associate editor at Cosmopolitan and has two years of experience writing about beauty, fashion, and lifestyle news. She’s an expert at researching and writing hair and skin stories, like the best shampoos for thinning hair and the best hair-growth oils, and feels especially knowledgeable in thickening shampoos thanks to her own struggles with—what she believes—was post-Covid-19 related hair loss. She regularly tests and analyzes thickening shampoos and hair products on her own hair for efficacy, while working with the industry’s top dermatologists, cosmetic chemists, and trichologists to assess new formulas and brands.

Lauren Balsamo is the deputy beauty director at Cosmopolitan with 10 years of experience researching, writing, and editing hair stories that range from the best hair detanglers to the best blue shampoos for brunettes. Her thickening shampoo picks were based on expert interviews and product testing.

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