Can brushing with a black toothpaste that contains activated charcoal—counterintuitively—whiten teeth? Will a “black” brushing routine give you a brighter smile?
What determines tooth color?
Tooth color is largely a reflection of the inner layer—dentin—together with the thickness, translucency, and shade of the outer layer—enamel.
Have you ever wondered why your canines look more yellow than your other front teeth? It is not just you. Dentin in the canines is thicker, so its reflection through the enamel appears yellower.
Beyond the tooth’s baseline shade, intrinsic (internal) staining may be present, and extrinsic staining that can be removed may also form (from smoking, coffee, tea, and more). Before whitening, start with a thorough professional cleaning with a dental hygienist, and treat stains according to their type. If you have front fillings, crowns, or porcelain veneers, their color will not change with whitening.
The internet is full of DIY whitening tips—strawberries, bananas, apples, activated charcoal—everything goes, and cheaply. A YouTube search for “home teeth whitening methods” returns more than 11,000 results. But what actually works?
Activated charcoal — not just for the grill
Some homemade whitening toothpaste recipes recommend activated charcoal as a whitening agent. What is activated charcoal, and how does it differ from ordinary charcoal?
Charcoal is usually made from wood or other plant material. To make it “activated,” it is processed at high temperature with a gas or other activating agent that greatly increases surface area and makes it porous—full of tiny pores that can adsorb toxins, gases, and other substances from the surroundings. In effect, the charcoal acts like a magnet, drawing unwanted materials into those pores and leaving its environment cleaner.
In the early 1900s the World Health Organization listed activated charcoal as an essential medicine for poisoning and overdose. Today its popularity is rising again—this time as a natural approach to binding toxins and chemicals. It is also used for intestinal gas, cholesterol support, hangover relief, and pregnancy-related bile issues. Popular uses include “internal cleansing,” weight management, skin health—and of course tooth whitening.
Home whitening — DIY?
Can a homemade charcoal toothpaste safely whiten teeth? The honest answer: there is no clear answer. There are no studies showing charcoal is effective for whitening. The concern with untested homemade products is that we cannot know how safe or effective they are for tooth structure and gum tissue. We know activated charcoal is effective and safe for toxin binding when taken as a swallowable tablet—but what happens when that tablet is crushed, mixed with water, and used as a paste? How abrasive is it? When online demonstrators want to prove their method works and saves money, they often brush vigorously for a long time on camera—that alone can explain the immediate improvement you see. Image editing is also frequently used to exaggerate results that are not real.
What we do know as of this writing is that only one charcoal-containing toothpaste on the market has been studied for whitening and stain removal: Black Is White toothpaste (Curaprox Inc.), sold in the U.S. and Europe for about $30 a tube. Its whitening effect comes partly from a blue shade that changes how light reflects from the teeth so they appear whiter. What sets it apart from homemade pastes is fluoride content (950 ppm) and nano-hydroxyapatite particles (nHAP). Electron-microscope studies have shown enamel-repair potential from hydroxyapatite particles. It also has a relatively low abrasivity (RDA 59 versus 70–90 for many commercial pastes) and contains no parabens or SLS.
In other words, a charcoal-based toothpaste may help remove stains, but it does not truly whiten the intrinsic tooth color. Prefer a paste with additional, proven benefits for oral health—and do not believe everything you see online.
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