Mustard Plaster

Mustard Plasters were used to treat many varied disorders in the days before modern medicine. Besides being used as a pain killer for backaches, they were also used to treat coughs and infections of the chest and lungs. A mustard plaster works by creating heat, drawing toxins out of the body and by providing nutrients that can be absorbed through the skin.

Assemble all the equipment beforehand.

Equipment List:

  • Pieces of thin cotton cloth. Preferably from old rags that you can throw away after using. You will need either 2 square pieces of cloth the size of the skin you want to cover, or 1 rectangular piece of cloth, double the size you want to cover, you can use flannelette from an old pair of pajamas or nightie. For a chest plaster, cut a piece about 12”x6”.
  • A means of holding the cloth against the skin: If you are putting the plaster on the chest, a tight-fitting old t-shirt would do. Old socks or gloves to hold on the hands. Long strips of cloth or a Tensor bandage for arms and legs. A towel warmed up in the dryer and folded up and put over the plaster if the person if lying down.
  • Measuring spoons
  • Something to spread the paste on the cloth
  • A disposable work surface, that is, something to put the cloth on while you are spreading the paste on it that can be thrown out afterward. I used a section of newspaper inside a plastic bag. You can also use waxed paper or a disposable under pad.

Mustard Plaster Ingredients:

  • Mustard powder. You can use either store-bought mustard powder or freshly ground seeds.
  • White Flour
  • Water

The ratio of mustard powder to flour will determine how much heat the plaster will give, and therefore how often it will need to be checked to make sure it is not burning the skin and whether or not it can be used overnight, on a child or on sensitive skin.

  • 1:8 very weak, safe for overnight (1/4 teaspoon mustard powder to 2 teaspoons flour)
  • 1:6 mild, suitable for children, safe overnight for an adult with normal skin (1/2 teaspoon of mustard seed powder with 1 tablespoon flour. Should cover a 6”x6” square area)
  • 1:4 strong. Good for relieving chest congestion due to colds, use only during the day or set and alarm clock if using at night.
  • 1:3 very strong. Adults only, not suitable for children. Check frequently for signs of redness.
  • When using a strong plaster, it is Ok for skin to turn pink, even red, but it should not turn raw or angry looking or blister. Remove plaster immediately if it shows any of these signs.


  1. Mix mustard and flour together. Add warm water to make a thin paste, not quite as thick as pancake batter.
  2. Spread the paste onto the pieces of cloth and then cover it with another piece of cloth.
  3. Making sure the skin is dry, place the plaster on the desired area.
  4. Check frequently to make sure there is no allergic reaction.
  5. Remove when skin begins to turn red, usually after 10-20 minutes using the 1:4 ratio.

Do not leave on longer than 30 minutes at a time. After removing the plaster it is best if the person can remain in bed and sleep for a couple hours. May be repeated after 2 hours, up to 3 times a day.

Adult chest plaster: 1 square foot. Cloth size 12”x24”, put the paste on half the cloth, and fold over the other half. 1 tablespoon mustard powder and 4 tablespoons flour. When making a chest plaster, you may want to have a hot ceramic plate nearby to put the plaster on briefly to warm it up before putting it on the skin. This is for comfort and is not necessary for the plaster to work.

Back of hand: 2 pieces of 4”x4” cloth, 1/8 teaspoon mustard powder, 1 teaspoon flour.

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