Magnesium Sulphate: What Are the Benefits?

• Common Name: Magnesium sulphate (Epsom salt)

• Category: Mineral salt

• Origin: Natural or synthetic mineral

• Form: White crystalline powder, soluble in water

• INCI Name: Magnesium Sulphate

• For: Blemish-prone skin, tired skin, bodies undergoing muscle recovery

• Functions: Soothing, relaxing, gentle exfoliant, purifying

• Dosage for Homemade Cosmetics: The dosage depends on the intended use: approximately 10–30% for a bath, 5–30% in a body scrub or face mask

• Solubility: Soluble in water, insoluble in oil

Magnesium sulphate is an ionic chemical compound consisting of a magnesium cation (Mg²⁺) and a sulphate anion (SO₄²⁻), usually bound to seven water molecules (heptahydrate form: MgSO₄·7H₂O). It occurs naturally in certain groundwater sources and thermal springs, and can be extracted or obtained by evaporating mineral-rich brines.

Magnesium's Various Forms

• Anhydrous (water-free): Highly drying (highly hygroscopic, and therefore not well suited to direct application to the skin), rarely used in cosmetics

• Heptahydrate: The most commonly used form (the well-known Epsom salt)

What Are the Benefits for the sSkin?

When applied to the skin, it works by:

• Osmotic effect: It draws water to the skin’s surface, which helps to decongest and soften dead skin cells

• Magnesium Supply: This trace element is involved in over 300 enzymatic reactions, particularly those related to cellular energy (ATP) and the regulation of inflammation

• Contains Sulphur: With gentle keratolytic properties, useful for regulating sebum and purifying the skin

And What About a Magnesium Sulphate Treatment?

Magnesium sulphate is also used in certain natural treatments as a short-term treatment. This treatment is traditionally administered as a bath or poultice to promote overall remineralisation, reduce tension and improve digestive or joint comfort.

For external use, a course of treatment involves taking an Epsom salt bath 2 to 3 times a week for 2 to 3 weeks. 

Although some people take magnesium sulphate orally (particularly for its laxative effect), this method is strictly reserved for supervised medical use and has no place in a beauty or wellness routine without professional supervision.

Soothing and Relieving Discomfort

Magnesium sulphate is recognised for its soothing properties. It is particularly useful as part of a skincare routine following skin irritation or after physical exertion. Thanks to its relaxing effects, it helps restore comfort to the skin and muscles, while reducing feelings of discomfort. It is also useful in daily skincare to soothe reactions caused by environmental or mechanical stress.

• Relief from muscle tension

• This relief is particularly sought after by people suffering from physical stress, muscular disorders or chronic tension. It can also be incorporated into a post-exercise recovery routine, alongside relaxing essential oils such as lavandin or wintergreen

• Soothing irritated or inflamed skin

• It can be used after shaving, hair removal, or prolonged exposure to the sun, either as a warm compress or diluted in a hydrosol spray. It is valued for soothing temporary redness and discomfort in sensitive skin

Decongestant

• Reducing localised swelling

• Its osmotic effect helps to draw excess water out of the skin’s superficial tissues. It is therefore particularly effective at reducing minor oedema, bags under the eyes, or even relieving heavy legs during a foot bath. This makes it the perfect companion after a good walk!

Sebum Regulator

• Controlling shine and enlarged pores

• Magnesium and sulphur have a mild astringent effect which helps to mattify the skin, reduce the appearance of pores and minimise shine on oily areas of the face

Purifying

• Deep Cleansing: When used in combination with ingredients such as clay, magnesium sulphate purifies the skin by helping to remove impurities and dead skin cells. It is particularly useful in skincare products for combination to oily skin prone to spots or blackheads

Gentle Exfoliant

• Non-Irritating Mechanical Exfoliant: Although effective, magnesium sulphate crystals are water-soluble, which limits their abrasiveness. This makes them a gentle exfoliant suitable for sensitive skin, removing dead skin cells without causing micro-lesions

Occasional Remineralising Treatment

• Transdermal Mineral Replenishment: When used in a bath or as a compress, magnesium sulphate allows for the transdermal absorption of magnesium, which is beneficial for the skin barrier and helps reduce oxidative stress in the skin. It is an ideal occasional treatment for tired, dull, or lacklustre skin

Our Epsom salt: for baths, purifying treatments, face masks, and poultices.

Our Epsom salt is a versatile cosmetic ingredient recognised for its remineralising properties, providing the skin with all the benefits of magnesium and sulphur.

Thanks to its fine grain size, it provides a gentle yet invigorating exfoliation. It can also be used to stabilise rich ‘water-in-oil’ emulsions, enhancing their texture. We particularly recommend it for making remineralising bath salts, homemade body scrubs, and creams and balms rich in plant oils.

Magnesium sulphate is compatible with most natural ingredients:

Clays (green, white): To enhance the purifying action. This combination is based on their physico-chemical compatibility in an aqueous phase, as mentioned in the Cosmetic Ingredient Review (CIR) report.

Discover Fine-Grained Illite Green Clay

Tea Tree Hydrosol: Frequently used in natural recipes alongside Epsom salt, these hydrosols are compatible due to their mild pH and water solubility.

Discover Tea Tree Hydrosol

Organic Peppermint Hydrosol

Invigorating and refreshing, this active ingredient tightens pores and revitalises a dull complexion. It is also known to soothe skin discomfort and is used to treat excessive sweating.

Discover Organic Peppermint Hydrosol

Organic Fine Lavender Hydrosol from Provence

Refreshing and soothing, this hydrosol is used to formulate skincare products for delicate, tight, or uncomfortable skin. Astringent and purifying, it is also a key ingredient in skincare products for blemish-prone skin.

Discover Our Organic Fine Lavender Hydrosol from Provence

Please Note

However, it is not recommended to combine it with AHA/BHA acids in the same skincare product without taking precautions, in order to avoid any skin irritation or dryness. This precaution stems from the CIR report, which highlights the osmotic effect of magnesium and the risks of skin dryness when combined with chemical exfoliants. 

Magnesium sulphate is a hygroscopic ingredient: it absorbs moisture from the air. It is therefore essential to store it in an airtight container, away from moisture and heat. 

Shelf Life: 24 months under optimal conditions.

Do not leave the jar open for more than a few minutes when using it.

• For external use only: do not ingest without medical advice

• Do not apply to broken or irritated skin, or after sunburn

• Not recommended for use by pregnant or breastfeeding women without professional advice

• Avoid contact with the eyes

• Keep out of reach of children

At Aroma-Zone, we offer a wide range of homemade recipes based on Epsom salt.

Thanks to its remineralising, soothing, exfoliating, and relaxing properties, Epsom salt can be used in a wide range of formulations, provided, of course, that you follow the recommended dosages and usage guidelines!

Here are three practical examples of recipes with different functions and sensory qualities, to illustrate the versatility of this essential natural ingredient.

Delphine is a biological engineer specialising in cosmetology. Passionate about cosmetics for almost ten years, she began making her own skincare products with Aroma-Zone ingredients to address her skin concerns. She then trained as a cosmetologist before creating her own bespoke cosmetics brand to address each person’s individual skin concerns.