15 Best Hair-Thickening Products to Transform Fine, Flat Strands

If you're looking for a product that helps downplay thinning hair, but also looks ~real~, you need to try this cult-favorite tinted powder. Just shake it throughout your roots, massage it in with your fingers, and the formula’s itty-bitty keratin fibers (the same protein in your hair) will cling to your strands to make them look seriously thick and full until you hop in the shower.

THE REVIEWS: “I am soooo happy with Toppik Hair Building Fibers!” writes one reviewer. “I am very self-conscious about my thinning hair, and I have tried everything. This is the best product for making my hair look thicker.”

This volumizing spray helps to not only protect my hair from heat damage while blow-drying, but to also leave it looking majorly full and amped-up by the end. How? Because of the formula’s PVP, a polymer that coats your strands to make them look thicker, along with watermelon fruit extract, an antioxidant that helps to protect hair from heat.

THE REVIEWS: “I have thin/flat hair and have tried MANY different products that promise volume/body and life!” reads one tester’s review. “They’ve all left my hair greasy, and even flatter than before. But not this stuff! It smells awesome, it gives my hair so much volume and it lasts! Two days later, and it’s still got some life! Love this product!”

This water-based serum is packed with moisturizing peptides and your early morning savior: caffeine. Caffeine, as a reminder, is rich in the type of antioxidants that can help reduce inflammation (a potential reason for stunted hair growth). Before bed, just massage a few drops of the serum throughout your scalp to help repair your moisture barrier, and, hopefully, get thicker, fuller hair over time.

THE REVIEWS: “I have been using this serum every time I wash my hair—one to two times a week—for a little over a month now,” writes one reviewer. “I section my hair to ensure even coverage of the scalp, and I take time to massage it in. I have noticed a HUGE difference in the thickness of my hair at the root, as well as hair loss.”

If you have curly hair or 4c hair, you probably already know the magic of this hair oil. But the hype is real, y’all, because it's loaded with sealing oils, like rosemary oil, castor oil, and jojoba oil that coat your hair and scalp to protect against water loss that can lead to dry, irritated scalp.

THE REVIEWS: “This is so good!!” one tester writes. “I've struggled with thin, very fine hair pretty much all of my life and I've searched for something to help even a little bit and this made my hair much thicker, healthier, and longer!! Definitely recommend!”

So you loaded up on thickening creams and mousses, but your style still falls flat in a few hours (a story I know all too well). Spritz on this highly rated, strong-hold hairspray to keep your roots lifted without weighing them down or leaving your hair feeling stiff and crunchy. And beyond its major hold, the formula also contains polymers that wrap around each strand to make your hair look a little thicker overall too.

THE REVIEWS: “If you want a spray that doesn't just coat the outside of your hair, but gives it body, shape and adds thickness, BUY THIS PRODUCT!,” writes one reviewer.

As much as I love dry shampoos and root powders for volumizing my hair, I don’t love how they leave my roots gunked up with product. Enter: This caffeine-based shampoo that improves the appearance of fine and thin hair to look bouncier and fuller-bodied. Its formulation also promotes both hair growth and strength.

THE REVIEWS: "I have fine hair but a good amount of it and it gets oily at my roots very quickly," writes one reviewer. "I use mousse, blow drying, and dry shampoo as much as possible to try to combat this. Now that I've started using this shampoo, my hair has never been more manageable. It feels so soft and has some texture while my roots stay lifted for around three days!!!! My hair has never gone this long without needing a wash or five pounds of dry shampoo. Also, the scent is a huge bonus, it smells like a bougie salon."

A spray...lotion? Yup! This v-affordable formula is ultra light, almost like water, and unlike any type of lotion you’re probably used to. It uses copolymers that coat your cuticles in a film to temporarily thicken your hair, says trichologist Evan Zhao. For best results, spritz it onto your towel-dried hair from the middle to the ends, then style your hair as usual.

THE REVIEWS: “Why has no one told me about this miracle potion?!?!” writes a tester in a review. “My hair is very fine, and it thinned after a major surgery. This product is amazing at giving thickness and volume. I’m now a customer for life.”

A greasy scalp is basically the antithesis to volumized hair. Which is why you should absolutely be dusting this powder through your roots when you want some body. The formula uses four types of starches to soak up oil and coat your individual strands to create the illusion of volume. Just shake the powder onto your dry roots and massage it in with your fingers, or sprinkle it on your hands and scrunch it into your hair for a lil extra body and texture.

THE REVIEWS: “This has become my go-to solution for next-day hair,” one reviewer writes. “I use just a little about an inch from where I normally part my hair and use my fingers to give the roots a nice boost. It works! My fine, thin hair looks full and like I washed it and blow-dried it with a round brush.”

The MVI (Most Valuable Ingredient) in this conditioner? Copolymers that temporarily plump up your hair strands to leave them looking thicker and denser. And unlike some conditioners that are filled with heavy oils, this one uses a mix of peptides and biotin to lightly moisturize without weighing you down.

THE REVIEWS: “I have a lot of hair, but it is very fine and limp, so I tried the OGX Thick and Full conditioner,” writes a tester. “I've noticed a great difference! I don't blow dry, just let it air dry. My hair is thicker and has more body instead of being so limp.”

If you can’t be bothered with a 10-step hair routine, try this hair-thickening spray, which volumizes with corn starch, strengthens with wheat protein, and moisturizes with castor-seed oil. Just spritz it through your towel-dried ends from root to tip, massage it through your hair, and blow-dry or air-dry for a smooth, volumized finish.

THE REVIEWS: “I have thinning, baby fine hair, and every time I use this I get compliments on how pretty and voluminous my hair looks,” one reviewer writes. “This is the only thickening product I've tried over the last 10 years that actually does what it says without weighing my hair down.”

I've been burned by mousse in the past that has left my hair feeling crunchy and heavy. But now, several years later, this ultra-light mousse exists, and it's nothing like the stuff from the early aughts. It coats my strands with polymers that help thicken up my hair while locking my hairstyle into place, yet doesn’t feel stiff or crunchy.

THE REVIEWS: “I have the thinnest, flattest hair, and this product makes my hair feel three to four times thicker,” writes one tester. “I have tried so many products over the years, and this has by far given me the best results.”

FYI: Trichologist Isfahan Chambers-Harris developed this hair-thickening treatment for moisturizing and soothing your scalp, which can inadvertently lead to fuller-looking hair and potential growth (remember: an inflamed scalp prob won’t produce denser hair). It uses a host of botanical extracts—like saw palmetto, lavender, and green tea—along with sealing rosemary, pumpkin, and safflower oils to coat your hair and reduce moisture loss.

THE REVIEWS: “A must have,” writes one reviewer. “I have never seen my daughter's 3c-hair respond to products like the ones available in this line. INCREDIBLE!!!”

My secret weapon for fuller-looking roots? This cover-up powder. I just dab it onto the sparse areas around my hairline and through my part with a dense makeup brush and blend it in—et voilà, my hair suddenly looks as thick as it did before I started bleaching it in middle school.

THE REVIEWS: According to one tester, “This hairline powder is a miracle. It works so incredibly well and looks natural. You would have to be inches from my scalp and know what to look for to realize that it wasn’t just my own hair. I’m so happy with this product, and I wish that I had found it years ago.”