14 Best At-Home Teeth Whitening Kits That Actually Work, According To Experts

“Hydrogen peroxide, the same enamel-safe ingredient dentists use for teeth whitening, is the main ingredient consumers should look for,” says Venneri. “For a teeth-whitening kit to be effective–meaning it attacks both extrinsic and intrinsic stains to bleach teeth beyond their natural color–it must contain one of two active ingredients: hydrogen peroxide (fast-acting, but increased sensitivity) or carbamide peroxide (slower-acting, but less sensitivity),” says Dr. Apa. You should also look for ingredients like peroxide droplets and potassium nitrate, which help to reduce sensitivity.

Kits with LED lights can help boost the results of the whitening formulas. “Blue light acts as a catalyst for the bleaching products,” says Dr. Lowenberg. “It increases the chemical reaction that hydrogen peroxide does.”

“I’ve seen teeth whitening have mental health benefits,” says Dr. Apa. “Think about it–when your teeth are whiter, you typically smile more, and studies show that smiling can have a positive impact on mood. You’re tricking your brain into happiness! Have you heard the saying, ‘when you smile on the phone, the other person can hear it?’ It’s something like that.”

Many kits recommend not eating or drinking for at least 30 minutes after whitening to avoid staining. Dr. Apa also suggests avoiding food or drinks with heavy coloring for 48 hours–think tomato sauce, red wine, berries, and coffee.

“The teeth can get temporarily sensitive,” says Dr. Lowenberg. “You don’t want to bleach if you have a cavity or decay, and you can’t bleach dental work, like crowns of porcelain veneers, because it won’t change color.”