Ingredient
Hydrogen Peroxide
The most-studied active in tooth whitening.
How it works. Diffuses through enamel into the dentin, breaking down the large chromogen molecules that trap stain color into smaller, lighter fragments.
Advantages
- Fastest visible cosmetic change
- Deep, intrinsic whitening
- Backed by decades of clinical research
Potential disadvantages
- Transient sensitivity
- Can irritate gums at high strengths
Common concentrations. OTC strips typically 6-14%. Professional in-office up to 40%.
Safety. Safe when used per label. Avoid on cracked enamel and existing dental work.
Evidence strength. Strong