Our testers were big fans of pens and their added convenience: You can paint it on and then go.

Whitening results depend on the current shade of your exact amount of shades your teeth improve will depend on how white they are to start. Teeth whitening strips are technique sensitive, and our tester appreciated the curved design which molded more naturally to their teeth — Professional Effects uses a rectangular bar that doesn't fit as easily. But we didn't consider these flaws dealbreakers, because Go Smile still produced impressive results and it was easy to fit them into our morning and nightime routines at home.

Since releasing the gel Fitbeauty365.com requires you to snap" the vials with a little pressure, they're also not the best for on-the-go — you'll be at high risk of accidentally whitening the inside of your bag. Pretty speedy, considering the average time until full results for the products we tested was 13 days. While the AuraGlow and Go Smile pens were unsurprisingly not the most powerful whiteners, they were convenient and easy to carry around for a quick touch up after that afternoon coffee.

Instead of simply repeating our extensive testing of the same (or functionally the same) products for the same results, we would try to answer a new question — which whitening product is the easiest and most comfortable to use? From these findings, along with ratings from Consumer Reports and beauty sites such as , and Men's Health, we concluded that the higher the peroxide content, and the better the surface contact (think strips over pens), the whiter the teeth. Go Smile On The Go Teeth Whitening Pen.

AuraGlow Teeth Whitening Pen, 35% Carbamide Peroxide. Lumeeno Teeth Whitening Kit 5 Large 44% Carbamide Peroxide Gels. Cool Teeth At Home Professional Teeth Whitening Kit 44% Carbamide Peroxide.

And, all of our products had to be available without a visit to — or prescription from — a dentist, which eliminated popular whitening systems Opalescence and Philips Zoom right off the bat. For our initial review of teeth whiteners we interviewed dentists, reviewed the research, and conducted at-home tests with over 30 participants to find the products that lived up to their promise of brighter teeth. The strips take 14 days to get full results (compared to Go Smile's seven) and require 30 minutes of wear time once a day.

There is no big secret to what makes the best teeth whitening products. -Twist at the base of the pen to dispense whitening gel onto the brush-on applicator. We also use fluoride-free natural whitening that combines the protective benefits of pure essential organ oil and coconut oil, along with other natural ingredients that help strengthen teeth, reduce plaque and whiten teeth with gentle polishing agents.

Our teeth whitening serum safely penetrates deep to whiten teeth thoroughly, then dissolves cleanly away with a refreshing mint aftertaste left behind.