What's in an Antiperspirant?

Listed below is an explanation of the most common ingredients in popular antiperspirants and deodorants - whether they be aerosol, stick, roll-on or similar. The list also includes the technical names for each ingredient so you can spot them on the back of the pack.

All of these ingredients have been thoroughly assessed by expert scientists. Combined, they provide a safe and effective means of controlling sweat and body odour.

Perfume & skin conditioners	Perfumes and fragrances are used in most deodorants and antiperspirants to mask body odour and provide a feeling of freshness to the user. Virtually all antiperspirant and deodorant products will contain some emollient oils to sooth and soften the skin by preventing water loss. In roll-ons and sticks, these also give a 'gliding' feeling as the product is applied. The moisturisers used in antiperspirants are usually glycerin or vegetable derived oils, such as Helianthus Annuus (a sunflower oil). Most antiperspirants will also contain masking oil to stop the product drying out into deposits, thus minimising what shows up on either skin or clothes. The active ingredients of antiperspirants and deodorants are often dissolved in alcohol because it dries quickly once applied to the skin and gives an immediate sense of coolness. Thus, alcohol is a common ingredient in many roll-ons, aerosol deodorants and some gels. Skin that has been sweating will sometimes have quite a greasy feel to it. Silica is a natural mineral which is often used in antiperspirants and deodorants to mop up this oiliness so that users no longer feel the greasy after-effects of sweat. Some antiperspirant products also include an ingredient called PEG-8 Distearate which makes it easier to wash the product off in the bath or shower at the end of the day.
Salts	Depending on the type of product, antiperspirants usually contain salts to actually reduce the flow of sweat from the skin. These salts work by dissolving in sweat and leaving a thin coating of gel over the sweat glands. This coating reduces the amount of sweat on the skin for a number of hours after the antiperspirant is applied. Aerosol and roll-on products will most likely contain ACH (Aluminium Chlorohydrate), whereas sticks, gels and other solid products are most likely to contain an antiperspirant salt called AZAG (Aluminium zirconium tetrachlorohydrex GLY). These salts provide the safest and most effective means of controlling sweat. Some people may be concerned about the use of aluminium in antiperspirants and other everyday products, believing that it can damage health. For example, it has been suggested that aluminium is a possible contributory factor for Alzheimer's disease. However, experts and research bodies including the Alzheimer's Society say there is no relationship between the two. In 2003 the U.S. Food and Drugs Administration published a major study which concluded that antiperspirants and their aluminium salts are safe.
Carriers & structurants	In order for antiperspirants to be effectively applied to the skin, they need to be held in some kind of carrying structure - whether that be the liquids used in aerosols or the solids used in sticks. Water is used in a range of antiperspirants as a carrier for other ingredients. It adds fluidity to products like roll-ons and creams and helps the product spread onto the skin. In aerosol products the active ingredients are contained in a neutral liquid which enables them to be easily sprayed onto the skin. This liquid (the most popular of which is cyclomethicone) is often combined with a slightly denser clay called disteardimonium hectorite which provides structure to the antiperspirant and stops heavier particles sinking to the bottom. In the same way that aerosols are transported via a carrier fluid, other more solid products need an agent which will provide structure and prevent the other ingredients from separating out. This structure can be provided by a combination of ingredients including Hydrogenated Castor Oil, 18-36 Acid Trygliceride, Stearath or Stearyl Alcohol. Most products contain a harmless antioxidant which ensures the other ingredients are in an optimal state when they reach the skin. You may find this referred to as BHT on the back of the pack.
Propellants	Aerosol antiperspirants and deodorants are designed to work via a thin film sprayed onto the skin. To create this film, products contain low, medium and high pressure propellants which produce a spray strong enough to reach the skin, but not too forceful. In the ingredients listing these propellants are called Butane, Isobutane and Propane.