This ‘One Pass’ Straightener Gave Me the Glossiest Hair of My Life and Is 20% Off

And it cut my styling time in half.

This ‘One Pass’ Straightener Gave Me the Glossiest Hair of My Life and Is 20% Off

Ask anyone who straightens their hair and they’ll tell you that the unicorn of tools is the “one-pass” flatiron. After 15 years of regular straightening without stumbling upon one, I too thought it was the stuff of hair legend—but then I got my hands on the Bio Ionic OnePass Styling Iron.

First, let me be clear: I don’t mean the “one pass” you’ve probably forced from a straightener at one point or another. Because we’ve all used our older sister’s or roommate’s flatiron, cranked up the heat to Thanksgiving-turkey levels, and sizzled and steamed our way to a pin-straight press. Not the case with this straightener. The difference with the Bio Ionic OnePass is that I can actually use it as a one-pass iron. And if you’ve got curly hair, you know that’s nothing short of a miracle.

Before: Curly, frizzy, and unblest by the OnePass
Shanna Shipin

I don’t generally use the hair typing system since I sit between a few, but my pattern has everything from 2Bs to 3Bs in it, with a solid amount of frizz. It’s relatively thick and medium-to-low porosity—meaning it doesn’t absorb moisture easily but it’s not particularly hard to style. In fact, heat truly loves my hair—which is part of the reason I’ve been a straightening fiend sinceI hit puberty. Another reason? When I straighten my hair, it stays straight—for days. And curly girls know, sometimes you just want an easy style to stay put without having to refresh it every morning. Bio Ionic does that for me, but takes it a step further by cutting down my styling time.

I’m a meticulous styler, so it usually takes me around an hour to straighten (and then wave) my hair—but with the Bio Ionic OnePass, it takes me 45 minutes max. That’s at least 15 more minutes to make coffee in the morning or, let’s be real, lie in bed and scroll through Instagram. And I don’t have short hair—it reaches down to the middle of my back.

When I first opened the Bio Ionic flatiron, I noticed the slightly matte finish on the outside and the pretty denim blue of the ceramic plates. It’s nice and light, and the plug fits into one outlet without blocking the other socket (this is not a performance point, but when you’re styling for longer than 20 minutes, you may as well charge your phone and play some music!). The iron leaves out the bells and whistles that most of the newly launched tools lean into—there are no special settings, touch screens, or fancy chimes to let you know when it’s ready for use. You just hit the “on” button, adjust the plus or minus sign to set your temperature, and you’re good to glide. It takes seconds to heat up the plates (which go up to 450 degrees), but the handle itself doesn’t get hot unless it’s on for at least 30 minutes.

Of course, the best part about the iron is its namesake one-pass ability. There’s no pulling, breaking, or denting—just sleek strands for days. Bio Ionic chalks it up to its patented silicone strips and natural minerals infused into the plates—a combination that’s supposed to give you smooth, glossy hair. And let me tell you, it delivers.

After: It straightens, it waves, it changes lives.
Shanna Shipin

Normally I have to run an iron through at least three times: the first to flatten out the curls, the second to seal the straighten, and then a third (albeit optional) to loosely wave the ends. Now it takes just one pass and I’m on my way to an Herbal Essences slow-mo hair toss. Plus, the straightener doubles as a curling iron, since it swivels super well. I love that I don’t need yet another tool to take up precious counter space in my bathroom.

In the short term, that’s less daily time spent styling, and in the long run, it means healthier hair. And what flatiron can promise that? At $199 you’re getting expert-level styling without shelling out an entire paycheck. They sure don’t make straighteners like they used to, and the Bio Ionic OnePass is proof.

Great news! You can score 20% off the Bio Ionic OnePass Styling Iron during Amazon Prime Day. Shop the styling tool below, then head here to check out all the other Amazon Prime Day sales happening this year.