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.”
This feature is particularly helpful if you have textured hair with waves or curls, which can become damaged so easily by heated styling tools. That said, it is not clear which heat setting is ideal for users with thick or somewhat straight hair. This may make this slightly more difficult if you are using a flat iron for curling purposes or if you need to straighten an especially thick head of hair each day! However, we are confident that a little tinkering is all it takes to find the perfect heat setting for these different hair types and styles, so you can rest assured that this hair straightener can still meet all your hair styling needs!
At $230, the Bio Ionic is pricier than any of our top picks. But you get what you pay for. You can truly do with your hair whatever you desire — straight or curled — in one pass. And, if you’re worried about it breaking a few years after purchase, the Bio Ionic comes with a five-year warranty. By investing in a better-quality tool up front, you won’t have to replace your flat iron every couple of years. Plus, the Bio Ionic goes on sale every now and then, so it’s worth keeping your eye out for deals.
Available with either ceramic plates (good for all hair types) or titanium ones (choice for curly, thick, and coarse textures), this innovative styler features touch sensor technology that lowers the heat when it's not being used, then automatically brings it back up to temp as soon as it's touched. Translation: No more waiting for your iron to heat up in between passes. Use it for smooth and sleek styles, or take advantage of the round brush-esque attachments to create more of a bouncy blowout effect.