Matcha May Cause Surface Stains, but Direct Evidence Is Limited

Matcha may gradually contribute to surface staining, particularly if you drink it frequently. However, direct clinical research measuring matcha stains on human teeth is limited. Claims that matcha stains more—or less—than coffee or black tea are therefore not well established.

The likely change is extrinsic discoloration: colored compounds collect on the outside of enamel rather than changing the tooth from within. The American Dental Association (ADA) lists tea among the drinks associated with extrinsic stains and notes that frequent consumption and poor oral hygiene can make this discoloration more noticeable (ADA).

What the evidence shows

Matcha is powdered green tea. It contains catechins, a group of plant compounds also found in other green teas, while chlorophyll gives matcha its vivid green color (review of matcha composition). This composition makes staining plausible, but it does not establish how much matcha stains teeth during ordinary drinking.

A 2024 laboratory study provides indirect evidence. Researchers immersed polished bovine enamel in two green teas, two black teas and two coffees for up to 72 cumulative hours. Every drink caused measurable discoloration, with black tea producing the largest change. The two green teas also discolored enamel, but the study did not test matcha (Italian Journal of Food Science).

That experiment also cannot reproduce everyday drinking. Teeth are not continuously submerged in tea, and saliva, oral hygiene, preparation, additives and differences in enamel can all affect the result. The most defensible conclusion is that matcha may cause gradual surface stains, not that it has a reliable place in a stain ranking against coffee or other teas.

A stain is not the same as decay or erosion

A matcha stain is a color change on the tooth surface. Pigment alone does not mean that enamel has been destroyed or that a cavity has formed.

Sweetened matcha drinks raise a separate issue. Plaque bacteria use sugars to produce acids, and frequent acid attacks can cause ongoing mineral loss and eventually a cavity (NIDCR). Unsweetened matcha does not provide the same added-sugar exposure. Sugar, sweetened milk and flavored syrups change the calculation, especially when a drink is sipped over several hours.

How to limit staining

You do not necessarily need to stop drinking matcha. These steps address staining without creating a new problem:

• Drink some water afterward. Water can help rinse away drink residue. The ADA recommends water and minimizing sweet add-ons when drinking tea or coffee (MouthHealthy).
• Finish sweetened matcha rather than sipping it for hours. This matters mainly because it reduces repeated sugar exposure, not because one sitting guarantees less staining (MouthHealthy).
• Keep to normal, thorough cleaning. Brush twice daily for about two minutes with fluoride toothpaste and clean between the teeth. The NHS advises spitting after brushing without immediately rinsing away the fluoride (NHS).
• Do not scrub harder or use lemon juice to remove color. More force can irritate gums and wear exposed tooth surfaces, while frequent exposure to acidic citrus can erode enamel.

Can matcha stains be removed?

Mild surface discoloration may improve with normal cleaning or a stain-removal toothpaste. Whitening toothpastes mainly polish away external stains; they do not bleach the tooth’s internal color. The ADA recommends choosing a stain-removal toothpaste with its Seal of Acceptance and using it as directed (MouthHealthy).

If discoloration remains, a professional dental cleaning may remove deposits and surface stains that home brushing cannot. Bleaching is different: it lightens natural teeth but does not change the color of crowns, veneers or tooth-colored fillings. The appropriate approach depends on the cause, as explained in this comparison of whitening options for different kinds of discoloration.

Do not assume every dark area is a matcha stain. Arrange a dental assessment for a new spot that does not clean away, a visible hole or rough area, pain, or one tooth that turns gray or dark. A single discolored tooth can reflect decay or a past injury rather than ordinary surface staining (Cleveland Clinic).