While deodorants and antiperspirants both help manage sweat they work differently. Here’s how:

• Deodorants usually do not contain aluminium, and they don’t stop you from sweating. 

• Deodorants help curb body odour and make sweat smell better by using fragrance or antibacterial compounds to reduce BO while antiperspirants make work to inhibit how much you sweat. 

• Antiperspirants usually contain aluminium, as do many deodorant-antiperspirants (which do the job of both an antiperspirant i.e. limiting how much you sweat plus the effects of a deodorant - making you smell fresh).

Antiperspirants work by blocking the sweat ducts which limits how much you sweat.

Aluminium salts, such as aluminium chloride, aluminium zirconium, and aluminium chlorohydrate are the most common ingredients in antiperspirants. These compounds form a temporary “plug” within the sweat duct that stops the flow of sweat to the skin's surface. These salts melt into your pores, creating a barrier and limiting the amount of sweat that comes out of them.

The aluminium in antiperspirants not only reduces wetness by blocking your underarm sweat ducts, they also help to reduce body odour by inhibiting the bacteria that feed on your sweat that produce the smell we know as BO.

Alum has been used for many years, as a deodorant, astringent and basic antiperspirant. Alum is found in crystal deodorants, a type of alternative deodorant in the form of potassium alum.

Crystal deodorant is usually available as a stone, roll-on, or spray. Often built as the alternative to conventional deodorant, alum still contains aluminium, often hydrated potassium aluminium sulfate, (otherwise known as potassium alum). There is no scientific evidence that suggests alum is not safe.