How to Make a Mustard Plaster (old-fashion heating pad)

Mustard plasters were used to treat many varied disorders in the days before modern medicine. Besides being used as a painkiller for backache, 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 being a source of nutrients that can be absorbed through the skin.

You will need:

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, nightie, or diaper/nappie. For a chest plaster, cut a piece about 12″ x 6″.

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 and gloves to hold on hands.
Long strips of cloth or an Ace elastic bandage for arms and legs
A towel warmed up in the dryer and folded up and put over the plaster if the person is lying down.
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 afterwards. I used a section of newspaper inside a plastic bag. You can also use waxed paper or a disposable underpad.


  • Mustard powder. (Either store-bought mustard powder or freshly-ground seeds)
  • White flour
  • Water
  • Measuring spoons
  • Something to spread the paste onto the cloth, such as a spatula
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.

1:4 Weak,- safe overnight
1:3 Mild  suitable for children, safe overnight for adult with normal skin.
1:2 Strong  Good for relieving chest congestion due to colds, use only during day or set alarm clock if using at night.
1:1 Very strong Adults only, not suitable for children. Check frequently for signs of redness.
When making and using a strong mustard plaster recipe, 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.
  2. Add warm water to make a thin paste, not quite as thick as pancake batter.
  3. Spread the paste onto the piece of cloth and then cover it with another piece of cloth.
  4. Cover area the cloth will be placed with a thin coating of olive oil.
  5. Place the cloth with the mustard plaster mi sandwiched in between  on the desired area.
  6. For additional warmth a warm towel can be placed on top of the mustard plaster cloth.
  7. Check frequently (every 5 minutes) to make sure there is no allergic reaction.
  8. Remove when skin begins to turn red, usually after 10-20 minutes using a 1:4 ratio. Do not leave on any longer than 30 minutes at a time.
  9. After removing the plaster rinse are with warm water.
  10. It is best if the person can remain in bed and rest for a couple hours after the treatment since the mustard plaster will typically bring congestion  and phlegm to the surface.

May be repeated after 2 hours, up to 3 times a day.

Tips for an Adult  chest plaster: 1 square foot. Cloth size 12″x24″, put 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 only for comfort purposes and is not necessary for the plaster to work.