Making an Epsom salt paste takes about two minutes: mix Epsom salt with just enough warm water to form a thick, spreadable consistency. The ratio is roughly two parts Epsom salt to one part water. That simple paste can then be applied to the skin to help draw out splinters, ease minor swelling, or soften the skin around boils.
Basic Paste Recipe
Start with two tablespoons of Epsom salt (magnesium sulfate) in a small bowl. Add one tablespoon of warm water and stir. The warm water dissolves some of the crystals while leaving enough undissolved salt to create a thick, grainy texture. You want something that holds its shape on your skin without dripping. If it’s too runny, add more salt. If it’s too dry and crumbly, add water a few drops at a time.
For a smoother paste that stays moist longer, mix in a small amount of glycerin, about half a teaspoon per two tablespoons of salt. Glycerin acts as a humectant, keeping the paste from drying out and crumbling off your skin within minutes. This is closer to how commercial drawing pastes are formulated. Pharmaceutical-grade magnesium sulfate paste, for example, contains 38.5% dried magnesium sulfate blended with glycerin to maintain a smooth, spreadable consistency.
How to Apply It
Spread the paste in a thick layer directly over the affected area. Cover it with a bandage, gauze pad, or adhesive strip to keep the paste in contact with your skin and prevent it from smearing onto clothing. Leave it on for about 30 minutes per session, up to three times per day. After each application, rinse the area with clean water and pat dry before reapplying fresh paste.
For splinters or small embedded debris, many people find it helpful to apply the paste at bedtime, wrap it with a bandage, and leave it overnight. The extended contact time gives the paste more opportunity to soften the surrounding skin and work the object closer to the surface. Check in the morning to see if the splinter has become visible enough to remove with clean tweezers.
Why the Paste Works
The paste relies on a simple principle: high concentrations of salt pull water toward them. When you pack a dense layer of magnesium sulfate against your skin, it creates an osmotic gradient. Fluid in the tissue beneath moves toward the saltier environment on the surface. This gentle drawing action can reduce minor swelling around a splinter, soften the skin enough to release a shallow foreign body, or help bring a boil closer to the surface where it can drain.
This is the same mechanism that makes Epsom salt effective as a soak, but a paste delivers a much higher concentration of magnesium sulfate directly to one spot. A typical bath dissolves a cup or two of salt in an entire tub of water. A paste puts nearly undiluted salt right where you need it.
Optional Additions
If you’re using the paste on a boil or an area that looks mildly inflamed, adding a drop of tea tree oil to the mixture can provide mild antibacterial properties. Tea tree oil has been shown to reduce inflammation and act against certain bacteria. Use only one or two drops per batch, as tea tree oil is potent and can irritate skin at higher concentrations. Never apply undiluted tea tree oil directly to broken skin.
Some people add a small amount of baking soda (about half a teaspoon) to the paste for additional drawing effect, especially for splinters. There is less clinical evidence behind this addition, but it does help create a finer-textured paste that spreads more evenly.
When a Paste Works Best
Epsom salt paste is most useful for shallow splinters that are visible but hard to grip, minor swelling around a small wound, or boils that are forming but haven’t yet come to a head. It works on the surface layers of skin, so deep splinters, large abscesses, or anything involving significant redness, heat, or streaking beyond the immediate area are beyond what a paste can address.
Avoid applying the paste to severely irritated skin or open wounds. The high salt concentration can sting and may further irritate damaged tissue. For children, plain Epsom salt without added fragrances or essential oils is the safest choice, as scented products are more likely to cause skin irritation.
Storage and Shelf Life
Epsom salt paste is best made fresh for each use. A pre-mixed batch without glycerin dries out within hours, and a batch with glycerin can develop bacterial growth if stored at room temperature for more than a day. Since the ingredients are inexpensive and mixing takes seconds, there’s little reason to make it in advance. Dry Epsom salt, on the other hand, stores indefinitely in a sealed container.