Messi Biology indicates that magnesium hydroxide (Mg(OH)₂), as a natural mineral ingredient, has been increasingly used in antiperspirants in recent years. Its antiperspirant mechanism differs from traditional antiperspirant ingredients (such as aluminum salts). Magnesium hydroxide controls sweat and body odor through a series of physical and chemical actions. The antiperspirant mechanism of magnesium hydroxide will be elaborated on below.
1. Hygroscopic Action (Moisture Absorption)
Magnesium hydroxide itself has a certain hygroscopic property. It can effectively absorb and lock in the moisture in sweat, reducing the time sweat remains on the skin surface. Through moisture absorption, magnesium hydroxide helps keep the skin dry, reduces discomfort caused by humidity, and prevents moisture from providing a suitable environment for bacterial growth. Humid environments usually exacerbate bacterial reproduction, leading to odor production, so reducing moisture accumulation helps prevent body odor.
2. Neutralizing Acidic Components in Sweat
Sweat is weakly acidic, mainly composed of water, salts, urea, amino acids, and fatty acids. When sweat comes into contact with bacteria on the skin surface, these organic components may be broken down by bacteria, releasing odorous substances (such as fatty acids, ammonia, etc.). Magnesium hydroxide is alkaline and can react chemically with these acidic components, neutralizing them and reducing the acidity of sweat. This neutralization helps reduce body odor caused by sweat decomposition, especially reducing the production of ammonia and fatty acids.
For example, ammonia (NH₃) is a common source of body odor. It reacts with magnesium hydroxide to form ammonium chloride (NH₄Cl), effectively reducing odor release.
3. Inhibiting Bacterial Growth
Bacteria are a significant source of body odor, especially in areas with high sweat production, such as the armpits. Bacteria break down organic matter in sweat, producing odor. Although magnesium hydroxide does not have strong antibacterial properties, it can, to some extent, inhibit bacterial growth. This is because the alkaline environment of magnesium hydroxide is not conducive to bacterial growth, especially some anaerobic bacteria that cause body odor, which reproduce poorly in alkaline environments. Therefore, magnesium hydroxide can indirectly control body odor production by reducing bacterial growth.
4. Regulating Skin pH
The skin surface usually has a natural acidic protective layer, which helps inhibit the invasion of pathogens. When sweating, this acidic protective layer may be altered by the components in sweat. Magnesium hydroxide, as an alkaline substance, can help regulate the pH of the skin, maintaining it within a suitable range. By maintaining the balance of skin pH, magnesium hydroxide avoids skin irritation, dryness, or inflammation caused by pH imbalance, thereby creating unfavorable conditions for bacterial growth.
5. Mildness and Skin Compatibility
Compared to many traditional antiperspirant ingredients (such as aluminum salts), magnesium hydroxide is less irritating to the skin. It is less likely to cause skin allergies, redness, or dryness, making it suitable for people with sensitive skin. Furthermore, the mildness of magnesium hydroxide also means that it does not cause pore clogging or burden the skin like aluminum salts. This makes magnesium hydroxide a safer antiperspirant, especially suitable for consumers who are sensitive to chemical ingredients or seeking natural ingredients.
6. Persistence and Usage Effectiveness
Magnesium hydroxide not only provides immediate moisture absorption and neutralization of acidic components in sweat, but also, due to its stability, its effects can usually last for a long time. Through long-lasting moisture absorption and neutralization, magnesium hydroxide can maintain skin dryness and freshness throughout the day. In addition, due to its mildness, there is no feeling of discomfort or stickiness after use, which makes it an ideal choice for daily use.