Alum is a hydrated aluminium potassium sulfate that possesses a specific crystal shape. It is non-toxic, dissolves easily in water, and reacts with various acids. The western desert of Egypt was the main source of alum substitutes in antiquity. It is the most natural hygiene measure in nature.
The alum stone has been used in cosmetics since ancient times. It has hypoallergenic, astringent, antiseptic and antiperspirant properties. Studies indicate that alum antioxidants fight metabolic damage and delay the ageing process, providing respite from the early signs of ageing, including wrinkles and dark spots. That is why alum powder is an essential ingredient in anti-ageing and anti-wrinkle creams.
Alum reduces the secretion of sweat and sebaceous glands. Therefore, it is widely used as a strong antiperspirant which eliminates unpleasant odours. It does not penetrate cells and does not impair sweat gland functions like aluminium compounds commonly used in deodorants. It dehydrates, and this kills the bacterial cells that are the source of the smelly odour. It does not cause allergies and can be used safely by asthmatics and pregnant women.
Besides, alum has other useful features; it reduces itching and swelling after mosquito and small fly bites. Also, you can use it in case of paradantosis and bleeding gums, because it stops bleeding. Due to the effects of astringent, it can be used after shaving to prevent skin irritation.