6 Best Hair Straightening Brushes, Tested and Reviewed

The Good Housekeeping Institute Beauty Lab has tested multiple types of hair tools, including curling irons, hair dryers and flat irons. In this test, we evaluated 11 hair straightening brushes by using consumer and laboratory testing methodology. A total of 55 women (five women per product) with various hair types were recruited to test 11 hair straightening brushes (five for each tool).

They were instructed to use the product following the manufacturer's directions on at least two separate occasions. After the testing period, testers completed a questionnaire rating ease of use, performance and overall satisfaction with a total of 955 questions tallied. In the Lab, experts measured the weight, cord length and temperature (surface and plate) for 10 minutes of use for each product. About 12,078 temperature readings were taken in total.

To find the most effective hair straightening brush, take into consideration the following factors:

✔️ Material: Straightening brushes typically have ceramic and/or tourmaline bristles that heat up to straighten hair, notes Wnek.

✔️ Heat safety: While most heated hair brushes have cool-tip bristles, the GH Beauty Lab found that these types of brushes "should come with a heat protectant glove as many of our consumers indicated that they wanted to push hair into the bristles with a flat hand," says Wnek. "If the product you choose doesn’t contain a heat protectant glove, we encourage you to purchase one to keep hands safe from potential burns." Like flat iron plates, these bristles heat up to 300º or 400ºF or more, so take caution.

✔️ Voltage: Take a look at the voltage of your brush. Many are safe to use both at home and abroad, but always consult your instruction manual of the product you're using. "Standard voltage is 120V in the US and 220-240V in Europe," shares Wnek. "If you see a range like 110-220V in a product manual or on the product’s electricals, it indicates that it is dual voltage and can be used at home and abroad."

✔️ Auto shut-off: Consider shopping for hair straightening brushes that feature an automatic shut-off for safety. No need to second guess yourself trying to remember if you turned it off or unplugged it!

✔️ Multiple heat settings: Having multiple heat settings on your hair straightening brush is helpful depending on your hair type. Fine or thin hair types don't always need as much heat as thick hair.

Yes, though they may be best for touch-ups rather than initially straightening hair. "Thick and/or curly hair consumers might find that they need to blow dry hair straight before use to make it easier to brush through hair with these devices," says Wnek. "Because of the design of these tools, it is hard to get into roots — you may need to use a flat iron or blow dry roots straight first." Another thing to note: These tools can take a while to heat up compared to other hair styling tools.

It depends on the look you are going for. "You can achieve a sleeker pin-straight look with flat irons, and you can also get creative with looks like curling or flipping out the ends," says Wnek. Skilled users can even curl hair with a flat iron. Hair straightening brushes are more limited to the looks you can create. "Because they are a bit bulkier, consumers noted it was hard to get into roots and to flip or curl out ends," she explains.

Hair straightening brushes give hair a more natural, smooth look, are easy to use and save time by brushing hair as they straighten it. "The similarity with both tools is that you must use them on dry hair, and both can cause heat damage, so make sure to use heat protectant and keep the tool moving when in contact with hair."

As with any hot tool, there is potential for hair damage. To avoid this, apply a heat protectant spray before using the straightening brush, and try not to overuse it. "Exposing hair to excessive heat for long periods of time can cause damage to the structure of hair," according to Wnek.

"Hair straightening brushes are electric paddle brushes with ceramic and/or tourmaline bristles that heat up to straighten hair," explains Wnek. In simpler terms, these hot brushes are a paddle brush and flat iron in one. "Hot air brushes or hair dryer brushes, as we like to call this category in the Lab, are innovative styling tools that release warm/hot air through the circumferential surface of a round or oval brush," she says. Meaning, a hot air brush is an oval brush and hair dryer combined. "These brushes style and smooth hair by applying tension through the brush on the wet hair while evaporating the moisture from it to set it." They are a more user-friendly option for those who style their hair using a round brush and a hair dryer.

Since hot air brushes don't emit air through a concentrated point like hair dryers (but rather 360 degrees), they have a much weaker airflow than traditional hair dryers, which means they can take longer to dry hair. "The biggest difference of all is that hot air brushes can be used on damp hair while straightening brushes should only be used on dry hair," says Wnek.

First things first, prep hair. As we mentioned above, if your hair is thick or curly, you may need to blow dry it smooth first to get very straight results. "These tools are to be used only on dry hair along with a heat protectant," advises Wnek. Start at the lowest heat setting, increasing as needed.

“To give hair body, position the brush underneath each section of hair while styling,” she says. “For a smoother look, glide the brush over the top of each section.” Brush slowly and steadily down hair, avoiding lingering in one spot.

GH Contributing Beauty Editor Dori Price most recently updated this story, adding new information about testing, existing product picks and new picks. Dori has more than 15 years of experience researching and writing haircare and hairstyling stories, combining her knowledge with the expertise of top industry professionals such as hairstylists, hair colorists and trichologists. She is an expert in all hair product categories, from shampoos, conditioners, hair thickening products, styling products and tools to hair color, professional services and more.

Price worked with GH Beauty Lab Senior Chemist Danusia Wnek, who coordinated and conducted the Lab testing on hair straightening brushes and also contributed her expertise on choosing the right brush. Wnek has spent seven years researching and developing testing protocols for haircare products within the GH Institute, including flat irons and hair dryer brushes.

GH Beauty Assistant Catharine Malzahn works closely with our pros to help deliver fact-based, science-backed beauty coverage. Over the years, she has interviewed experts, written product reviews and tested hundreds of hair products, including professional hair treatments, hot tools, shampoos, conditioners, styling products and more. She wrote the original version of this guide.