Like most millennials, my coworker Brittany and I love taking selfies and flashing our pearly whites on Instagram.
teeth whitener drugstore vs. sephora
photo: Revelist/Jessica Torres/ Brittany Fowler

Because we both want smiles shinier than the Chrysler Building, we decided to try two different 10-day teeth whitening kits at both high and low price points. 

See whose smile came out on top below...

Brittany already has a bright smile, but she was excited to try and make her teeth even whiter.

drugstore vs. sephora teeth whitener
photo: Revelist/Jessica Torres

"Yes, my teeth are already on the white side — I’m calling myself out before you do it for me. I brush my teeth twice a day and floss maybe once a year, but I wanted whiter teeth, because why not?" said Brittany. 

For this test, she'll be giving these $18 Crest 3D Whitestrips a try.

drugstore vs. sephora teeth whitener
photo: Revelist/Brittany Fowler
The box includes enough strips for 10 treatments of your top and bottom teeth. 

>>Click to buy 

Being the perfectionist that she is, Brittany made sure to read the instructions before getting her hands dirty.

drugstore vs. sephora teeth whitener
photo: Revelist/Jessica Torres

The longer strip is meant for your top teeth and the shorter strip is for your bottom teeth. The directions tell you to wear them for 30 minutes once a day, or an hour if you want to be extra.

When your time is up, remove and dispose of the strips. "I often had a gel-like residue on my teeth that I rinsed out with a few swigs of water," said Brittany. 

Nothing about the process is glamorous. 

drugstore vs. sephora teeth whitener
photo: Revelist/Jessica Torres

You peel off the strip, align it with your teeth, and then fold it over to keep it in place. Sounds easy, but there’s a lot of lip action involved trying to get the damn things in your mouth.

"There is a taste, but it won’t trigger your gag reflex," said Brittany. "After 10 minutes, I wanted to take them off, but Jess stopped me in the name of science."

Now let's talk about how my teeth looked before.

drugstore vs. sephora teeth whitener
photo: Revelist/Brittany Fowler

My teeth aren't yellow, but they definitely aren't as white as I would love them to be. So when our editor asked us to try cheap vs. expensive whitening products, I jumped on the expensive one. Plus, I'd tried a drugstore teeth whitener before and it irritated my sensitive teeth.

I tried the 10-day Glo Science kit, which is sold at Sephora for $75

drugstore vs. sephora teeth whitener
photo: Revelist/ Jessica Torres

The kit includes 10 individual tubes (which reminded me of Kool-Aid tops) and a shiny lip balm.

>>Click to buy

Luckily, Glo Science is made for sensitive teeth. It's also supposed to be less messy. 

drugstore vs. sephora teeth whitener
photo: Revelist/Brittany Fowler

Based on the instructions, each tube lasts for three uses a day — one in the morning, afternoon, and night. It was up to me to use an equal amount each time. 

I curled my lips to avoid contact with the gel and applied it in circular motions.

drugstore vs. sephora teeth whitener
photo: Revelist/ Brittany Fowler

I first applied the included lip treatment, which was surprisingly pleasant and not too sticky or thick. After rubbing the whitening gel into a nice foam, I let it dissolve on its own. 

The vegan teeth whitener was safe to swallow, but it grossed me out. 

photo: giphy

The gel and my saliva made the most disgusting combo, which I had to spit out after. I later learned to apply the gel while tilting my head to avoid too much drool. 

Once we got the hang of our products, we were ready to see results.

drugstore vs. sephora teeth whitener
photo: Revelist/Brittany Fowler, Jessica Torres

Brittany: LOL, did you really think I’d see a noticeable difference after one treatment? Nah. If all it took was one treatment, I’d do this every month!

Jess: I live for instant gratification, so I was really expecting to see a difference. I was wrong.

drugstore vs. sephora teeth whitener
photo: Revelist/ Brittany Fowler, Jessica Torres

Brittany: Here, my teeth have gone from off white to cake frosting white. I will say I’m glad I only have to do this once a day, unlike my partner in crime, Jess, who’s committed to three times per day.  
Jess: I saw no visible difference on the third day, and I was annoyed that I had to take off my lipstick to apply the treatment three times a day.

drugstore vs. sephora teeth whitener
photo: Revelist/Brittany Fowler/ Jessica Torres

Brittany: Helloooooooo sensitivity! I woke up after the sixth treatment and knew my journey was over. Every time I breathed in the frigid winter air my bottom teeth felt it down to the root. By this time, I'd started to see a slight difference, but those last four treatments are definitely necessary for other people to notice. Too bad my teeth bailed, it looks like I could’ve won this teeth-whitening competition!

Jess: On the sixth day, I learned a very important lesson: If they tell you to wear a generous amount of the moisturizer on your lips before applying the treatment, DO IT! I completely forgot to apply the lip treatment and my lips began to burn like they had hot sauce on them.

Since day 6 was Brittany's last treatment, here are her final results.

drugstore vs. sephora teeth whitener
photo: Revelist/Brittany Fowler

Days 7-9 had me starring at my reflection nonstop, but I couldn't see dramatic results. 

photo: Giphy

Being so close to the end but not seeing results was frustrating. I had to set alarms on my phone to remind myself to whiten my teeth three times a day.

Here are my final results. 

drugstore vs. sephora teeth whitener
photo: Revelist/Brittany Fowler

Even though I was having a hard time seeing results on a daily basis, I saw a decent change in the final photos. When I saw the side-by-side of my teeth from day 1 to 10, they appeared a couple shades whiter. 

WINNER: Based on cost, convenience, and results, Crest is our winner. 

If Brittany hadn't become sensitive to the strips, she would have definitely won. 

Our results weren't vastly different, and Crest was much more convenient (once per day vs. three times) and cost effective. I had trouble getting three full uses out of one Glo Science ampoule; it takes a bit of measuring to get the right amount every time. Plus, I used mine for 10 days and she only used hers for six and she still saw results. 

As for the sensitivity, Brittany has tried Crest Whitestrips before and had no problem. "I'll chalk the sensitivity I had this time up to aging, right along with hangovers after two glasses of wine," she said. 

Check out a video recap below.