Most whitening products work in one of two ways: they bleach the chromogen compounds inside the enamel using peroxide, or they physically abrade the stained surface layer using a fine grit. Both approaches work. Both also have limitations - sensitivity from peroxide, enamel micro-abrasion from aggressive polishing.
Bromelain offers a third mechanism, and it’s one that most people have never heard of.
What bromelain is
Bromelain is a protease enzyme - a protein-dissolving enzyme - extracted primarily from pineapple stem. It has a long history in food science and medicine (it’s used as a meat tenderiser, and in clinical settings for reducing inflammation and supporting wound healing). Its application in oral care is more recent, but the science behind it is straightforward.
How it whitens teeth
Tooth staining works roughly as follows. Your teeth are covered by a thin organic film called the pellicle - a layer of proteins, glycoproteins, and lipids that form naturally within minutes of brushing. This pellicle is what coloured compounds in food and drink - tannins in tea and wine, chlorogenic acid in coffee - bind to. Over time, these compounds penetrate deeper into the enamel surface, causing the staining that becomes increasingly resistant to mechanical removal.
Bromelain’s mechanism targets this process directly. As a protease, it cleaves the protein bonds in the pellicle that stain chromogens attach to - dissolving the stained surface layer rather than bleaching the compounds inside it or grinding the surface away. The result is stain removal without the sensitivity associated with peroxide and without enamel stress from aggressive abrasion.
How this compares to other whitening methods
Peroxide whitening
Hydrogen peroxide and carbamide peroxide are the active ingredients in most in-surgery and take-home whitening treatments, and in some whitening toothpastes. They work by oxidising the chromogen compounds inside the enamel, which is genuinely effective - but they also penetrate the dentinal tubules, which can trigger sensitivity, particularly with repeated use. Some research also suggests that peroxide has effects on the oral microbiome, though evidence here is still developing.
Abrasive whitening
Most whitening toothpastes achieve their effect primarily through abrasion - using higher concentrations of hydrated silica or other mild abrasives to polish stains off the tooth surface. This works for surface staining but raises enamel wear concerns with regular use over time, particularly if the Relative Dentine Abrasivity (RDA) value is high. Laro’s toothpaste is specifically formulated with a low-RDA profile: kaolin clay for gentle polishing, rather than aggressive silica.
Enzyme whitening
Bromelain works on the pellicle layer, not inside the enamel. This means it doesn’t cause the sensitivity associated with peroxide, and it doesn’t require abrasive grit to achieve results. It’s particularly well suited to people with sensitive teeth, enamel erosion concerns, or those who simply want to avoid more aggressive chemistry in their daily routine.
The published evidence
Clinical research on bromelain in oral care - including its combination with papain, another protease enzyme - has shown statistically significant improvements in tooth colour scores compared to control groups using standard toothpaste. Studies have also confirmed its safety for enamel and gum tissue at the concentrations used in toothpaste formulations. It’s not a substitute for professional cleaning, but as a daily whitening mechanism, the evidence base is solid.
One thing to set expectations on
Enzyme whitening works on extrinsic staining - the surface stains that come from food, drink, and lifestyle. It doesn’t change the intrinsic colour of your dentine (which determines the baseline shade of your teeth and is what peroxide treatments address). If you’re looking to noticeably lighten your natural tooth shade, a professional whitening treatment is the appropriate route. If you’re looking to keep your teeth as bright as their natural shade allows, and to do so gently and daily, bromelain is well suited to that job.
→ Laro’s Naturally Whitening Toothpaste contains bromelain alongside kaolin clay, hydroxyapatite, and xylitol - a complete gentle whitening system. Explore the range.