Magnesium hydroxide

Magnesium Hydroxide, also known as milk of magnesia or mineral brucite, is an inorganic compound with the chemical formula Mg(OH)2. In its raw material state, it appears as a fine, white, odourless powder, typically derived from seawater or naturally occurring magnesium minerals through a precipitation process.

In cosmetic formulation, it is primarily recognised for its alkaline nature and its ability to neutralise acidic compounds. Body odour develops when bacteria on the skin break down components of sweat into acidic, volatile compounds, and Magnesium Hydroxide works by raising the pH of the skin's surface, creating an environment less favourable to the bacteria responsible. This mechanism sets it apart from antiperspirants, since it does not block sweat glands or interfere with the body's natural ability to regulate temperature.

Beyond deodorant use, it also functions as a general pH adjuster and a mild absorbent ingredient, giving it a role in oil control products such as primers and clay masks. Its gentle profile and non gritty texture have made it a popular ingredient among formulators building natural, aluminium free personal care products.

Magnesium Hydroxide is a strong choice for formulators developing natural, aluminium free deodorants. Rather than blocking sweat glands like a traditional antiperspirant, it works by neutralising the acidic compounds that cause odour, giving customers a gentler alternative that still delivers noticeable freshness throughout the day.

Its gentle alkalinity also makes it a more comfortable option for sensitive skin compared with some other natural deodorant ingredients such as baking soda, which can be more irritating for certain skin types when used at higher concentrations. This makes Magnesium Hydroxide a useful ingredient for formulators wanting to serve a wider range of customers, including those with reactive or easily irritated underarm skin.

Beyond deodorant, its dual function as a pH adjuster gives formulators added flexibility, allowing it to be used to fine tune the overall pH of a wider formulation where needed. Its mild absorbent properties also support its use in oil control products such as mattifying primers and clay based masks.

Its fine, non gritty particle structure contributes to a smooth, silky texture in finished products, helping avoid the grainy feel that some mineral powders can introduce into a formulation, particularly in creams and solid deodorant sticks.

Magnesium Hydroxide is typically blended evenly into a formulation rather than dissolved, since it does not fully dissolve in water. In cream or solid deodorant recipes, it is commonly combined with ingredients such as shea butter, coconut oil and arrowroot powder, creating a smooth, effective base that helps manage both moisture and odour.

When formulating, it is important to disperse the powder thoroughly to avoid a gritty texture in the finished product, particularly in cream and stick formats where a smooth application is expected. Some formulators pair it with additional odour locking ingredients, such as zinc ricinoleate, for a more complete dual mechanism approach to odour control.

As a pH adjuster, it can also be added in smaller amounts to help bring a wider formulation to a desired alkalinity, though care should be taken not to raise the pH too high, since overly alkaline formulations can disrupt the skin's natural acid mantle and increase irritation potential.

As with any new ingredient, run a small patch test before wider use and check compatibility with your other chosen ingredients. Always refer to the technical documentation provided for full handling, dosage and storage guidance.

One of the main benefits of Magnesium Hydroxide is its ability to neutralise odour causing acids without blocking sweat glands, making it a genuine deodorant active rather than an antiperspirant. This appeals strongly to customers looking for a natural approach to freshness that still works with the body's normal function.

Its gentle profile is another significant advantage, particularly for sensitive skin formulations. Compared with baking soda, which can cause irritation for some users at higher concentrations, Magnesium Hydroxide tends to be better tolerated, widening the potential customer base for a finished deodorant product.

As a dual function ingredient, it also supports pH adjustment within a formulation, giving formulators flexibility to fine tune stability and skin compatibility without introducing an entirely separate raw material for that purpose.

Its fine, non gritty particle structure supports a smooth, pleasant finish in creams and solid sticks, avoiding the grainy texture that can sometimes come with mineral based powders. Combined with its aluminium free profile and general safety record in cosmetic use, Magnesium Hydroxide remains a dependable, versatile ingredient for natural deodorant and skincare formulation.

• Arrowroot Powder, a natural starch that improves texture and absorbency in deodorant formulations
• Shea Butter, a rich butter that forms a smooth, nourishing base for cream deodorants
• Zinc Ricinoleate, an odour locking ingredient that complements magnesium hydroxide for enhanced freshness
• Coconut Oil, Refined, a neutral oil that blends easily into solid deodorant stick formulations
• Kaolin Clay, a gentle absorbent clay that pairs well in mattifying and oil control products