SmileDirectClub's $79 LED whitening kit worked exceptionally well - and it didn't cause me any teeth sensitivity

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• SmileDirectClub's $79 Teeth Whitening Kit is said to work three times faster than whitening strips. It uses the same safe, effective whitening agent as a dentist's office, but costs much less than a professional treatment.
• I used it, and after a few applications, my teeth were about three shades whiter - and the formula didn't cause any sensitivity.
• For more options to consider, read the Insider Picks Buying Guide to the best teeth whitening kits you can buy.

Whether it's coffee, smoking, red wine, soy sauce, or the inexorable compounding of time, your teeth take quite a beating from everyday life. Even if you brush and floss the recommended amount with the aid of whitening toothpaste, the simple act of being alive seems to be in constant opposition to a bright, white smile.

Unfortunately, your smile is one of the first things people notice. In the seconds it takes your brain to assemble its first impression, one's smile often lands the leading role. Thankfully, the availability of cheap, effective whitening kits has made white teeth both more common and more taken for granted. While still semi-cosmetic, the act of whitening has started to blend into a wider definition of oral hygiene.

Recently, the same startup known for online braces has released an at-home LED teeth whitening kit. Like its 3D-printed clear aligners, SmileDirectClub's $79 kit is supposed to deliver the advantages of a dentist's office at about 60% less cost. The LED kit is estimated to be three times faster than whitening strips.

To see if it's actually effective, I tested the $79 Whitening Kit myself. It comes with nine whitening pens (what the startup estimates as two full whitening treatments) and an LED mouthguard and storing case. It reminded me of the much more expensive but effective $220 Glo Brilliant Whitening Device, which also uses an LED mouthpiece to act as a catalyst for hydrogen peroxide.

To use, you twist one of the whitening pens to drive the gel to the applicator, apply it to your teeth evenly (avoiding gums), and pop in the mouthguard with its LED accelerator light. After five minutes, you remove the light and unplug it from your phone. Spit out the excess foam and use lukewarm water to rinse the mouthguard. Do this twice in the morning, and twice at night for a full four sessions. Avoid eating foods that can stain your teeth for 24 hours. According to SmileDirectClub, you should whiten for one week every six months.

In person, the device is well-designed and easy to use. The LED light mouthguard is hands-free and smart-phone powered (iPhone or Android), so you can be tethered to your phone rather than an outlet. It requires minimal battery power to run, and this solves any issues with needing to charge a device before using - a con of the Glo Brilliant device. SmileDirectClub says the nine whitening pens should equal two full treatments (plus a bonus pen), but I found their estimates to be extremely conservative - even with evenly coating my teeth in gel, I got about four times more use out of the pens than expected. Once you run out, a replacement of whitening pens is $29 for four.

You could technically just buy the whitening pens and use them without the mouthpiece to save money initially, but it's the LED light - and how the hydrogen peroxide reacts to it - that is likely to give you the best results. If you're not interested in the LED mouthguard, you may just want to stick to strips.

SmileDirectClub's formula is the same enamel-safe formula dentists use, but it's supposed to break down to about $40 per treatment (which, in my experience, was closer to $20). It's safe to use on crowns, veneers, and caps, and the formula is lactose-, soy-, and gluten-free, as well as vegan.

In short, SmileDirectClub's Whitening Kit does work. It made my teeth whiter after one day's worth of sessions and continued to make them more even and bright with ongoing use. After continual applications, my teeth were about two to three shades whiter. Since I didn't begin with intense discoloration, I mostly noticed an evening in tone - my teeth are brighter, and the white is more universal and intense. I didn't notice any increased sensitivity, and the process was easy, clean, and relatively intuitive. However, you do have to be willing to use it routinely.

All in all, it's a good option if you're considering it. SmileDirectClub is $79 and white strips are $30 on a good day, but it's far cheaper than another prominent LED system (Glo Science) and you can eek out more uses of the whitening pens than the company estimates. It's also faster to use, as four five minute sessions broken up feel a lot more bearable than one 30-minute session. It's even convenient to multitask with it in so you can fit it into a morning routine without much effort. And, most important to me aside from efficacy, it didn't make my gums tender or my teeth ache.

If you're looking for fast, noticeable results that are relatively easy to fit into your life, SmileDirectClub's whitening kit is worth checking out.

SmileDirectClub Teeth Whitening Kit, available on Amazon, $79