The four million sweat glands in our body pump out several litres of sweat every day, which probably explains why many of us report that sweating can be a problem.

More than a million people in England alone are believed to suffer from excessive sweating or, as it’s known in the medical world, hyperhidrosis.

Deodrants work by covering the smell of sweat with a fragrance. Antiperspirants are the main defence against excessive sweating, but how well a product works for you depends on many factors including its ingredients, the strength of those ingredients, how much you perspire and even when you apply it.

Antiperspirant tips

Antiperspirants come in different types, including aerosol, sticks and roll-ons.

Make sure your underarms are as dry as possible so that the antiperspirant’s active ingredients have a chance to do their job by seeping into pores and plugging sweat ducts.

If your armpits are damp - as they are after you towel off from a shower - the antiperspirant will mix with that wetness and slide off your skin instead of into the sweat ducts where you need it most.

Some antiperspirants are best applied at bedtime, when your underarms are dry and you’ve got about eight hours of relatively sweat-free slumber to allow the ingredients to go to work.

What's in antiperspirant?

The safety of antiperspirants and their ingredients are regulated by the EU Cosmetics Directive. Manufacturers have to make sure products are safe to use and have to keep information available on the formula, safety and stability of products.

Here’s the information on the key antiperspirant ingredients you need to combat excessive sweating and feel fresh all day.

Aluminium salts, zirconium salts and aluminium chloride. Aluminium chloride is found in more powerful products and those available on prescription. It effectively plugs up sweat ducts to temporarily stop the flow of moisture to the skin. Over-the-counter, clinical-strength antiperspirants contain higher concentrations of aluminium chloride.

Aluminium chloride antiperspirant needs to be applied before bedtime and washed off in the morning.

If it is used on the face, it must be kept out of the eyes. Men using the product need to avoid shaving 24 hours before and after using it on the face.

Cancer Research UK says there is no evidence that aluminium in deodorants could increase the risk of cancer in animals or humans.

Parabens. These preservatives helped keep cosmetic products free of bacteria, but most modern deodorants are parabens-free.

If you’d prefer to avoid parabens, check your antiperspirant’s ingredients list for words ending in "-paraben" such as methylparaben or propylparaben.

A small study conducted in 2004 found traces of parabens in breast cancer tumours, suggesting that they may have weak oestrogen-like effects if absorbed through the skin. The study didn't find that parabens caused breast cancer, or that the parabens were from antiperspirants. As Cancer Research UK puts it: "Finding parabens in tumours is a far cry from saying that it causes breast cancer."