I get canker sores whenever I am stressed. Right before a big presentation at work, or a trip I am nervous about — my mouth decides to grow a tiny painful crater on the inside of my lip. I have tried numbing gels, salt water rinses, avoiding acidic food. They all took about a week to work, which is about the length of time a canker sore takes to heal on its own anyway.

Why a Tea Bag Actually Works

Black tea contains tannins — the same compounds that give tea its bitterness and make your mouth feel dry. Tannins are astringent, meaning they contract tissue and reduce inflammation. They also have mild antibacterial properties.

When you press a moistened black tea bag directly on a canker sore, the tannins draw fluid out of the inflamed tissue, dry out the sore, and create a protective layer over the raw nerve endings. It is basically the same principle as those tiny medicated patches you buy at the drugstore, except a tea bag costs basically nothing.

How to Do It

1. Use a black tea bag. Not green tea, not herbal. Black tea — Lipton, Tetley, whatever. The darker the tea, the more tannins.
2. Steep the tea bag in hot water for about a minute, just like you are making tea. Then take it out and let it cool until it is warm but not hot enough to burn your mouth. Squeeze out the excess liquid.
3. Press the warm tea bag directly on the canker sore and hold it there for 5 to 10 minutes. Apply gentle but steady pressure. It will feel slightly astringent — like the sensation of drinking strong tea.
4. Do this right before bed. Do not rinse your mouth after. You want the tannins to stay on the sore overnight.

The first time I tried this, I woke up the next morning and the sore had shrunk by half. The raw nerve pain was mostly gone — it just felt like a regular spot in my mouth instead of a miniature open wound. By the second night it was barely noticeable.

What to Avoid While It Heals

Even with the tea bag trick, you have to stop irritating the sore. Avoid:

• Acidic foods and drinks: Orange juice, tomatoes, pineapple, soda. They burn on contact and slow healing.
• Spicy or salty foods: Chips, hot sauce, anything that stings.
• Sodium lauryl sulfate (SLS) toothpaste: Some people (including me) find that SLS triggers canker sores. Switching to an SLS-free toothpaste like Sensodyne made a noticeable difference in how often I get them.

I keep a box of black tea in my bathroom cabinet now. Not for drinking — I do not even like black tea. It is just there for the canker sores.