Despite these downsides, the HSI Professional comes with plenty of positives, including extras not often found with other hair straighteners. Along with the straightener, you'll receive a carrying case, a heat-resistant glove for easier hair styling, a style guide, and a travel-size argan oil leave-in hair treatment serum to smooth and protect your hair. This is more than most high-end hair straighteners come with, all for a fraction of the price.
The type of heat you use to style your hair makes a big difference in how healthy it will be. Our Xtava Pro-Satin Infrared Ceramic Flat Iron for Hair uses infrared heating technology, which heats hair from the inside out. Infrared technology is a game-changer for styling your hair because it allows heat to penetrate directly into the inner part of the hair strand, not just the outside layer. Infrared heating to the middle of the hair strand provides a more effective heat for styling and decreases damage to the outside of your hair. Infrared technology also stimulates negative ions in your hair that draw oils from the hair shaft to the surface; this helps lock in moisture and lock in your look, even in humid weather. Better heat = better hair health. Guess that’s not much of a secret after all, is it?
“The temperature of the iron can determine the curl pattern on hair that tends to fall easily, as you might need a higher heat to lock in the pattern closer to the root,” she added. “The internal components of the irons also can determine the curl pattern, and that is why it is important to invest in custom, high-end tools that contain internal heaters that go the entire length of the barrel. The higher the heat, the stronger the curl will essentially be. Low heat will produce a softer finish.”
The Bio Ionic worked well on all of our testers’ hair, but it’s best on drier hair with a medium thickness. We spritzed testers’ hair with some keratin smoothing treatment, but the Bio Ionic did a lot of the heavy lifting to make our hair feel softer. The tool gets hot, but not too hot to grip, and it excels at creating the silky volume you want without making your hair pin-straight and flat. One tester put it perfectly: “[The Bio Ionic] is the Rumplestiltskin of hair straighteners. It’s turning straw into gold.”

Xtava’s two inch-wide plates are massive, making them perfect for people with thick or coarse hair. Aside from the plates, everything else about this flat iron is fairly standard. You can use it at a temperature range in between 265 and 445 degrees Fahrenheit, the plates are made with tourmaline and ceramic, and it takes less than two minutes for the tool to fully heat.

Straightening irons, straighteners, or flat irons work by breaking down the positive hydrogen bonds found in the hair's cortex, which cause hair to open, bend and become curly. Once the bonds are broken, hair is prevented from holding its original, natural form, though the hydrogen bonds can re-form if exposed to moisture.[2] Straightening irons use mainly ceramic material for their plates. Low-end straighteners use a single layer of ceramic coating on the plates, whereas high-end straighteners use multiple layers or even 100% ceramic material. Some straightening irons are fitted with an automatic shut off feature to prevent fire accidents.


An upgrade from their since discontinued Eclipse Styler, you won't be tempted to heat this flatiron up to 450 degrees, because the temperature dial is always stuck on one number: 365 (the ideal heat to mold hair without frying it, according to the scientists at GHD). Underneath each of those 365-degree plates are three fancy sensors that measure the density of the hair in the iron so that it can maintain consistent heat regardless of the chunk of hair you grab. The result? Silky, shiny hair with zero frizz.
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