Q. I tend to suffer from excessive perspiration under my arms, which can be very embarrassing. A friend said Botox might help. Is this correct and if so, is it available on the NHS or privately?

A. Most people think of botulinum toxin as a non-surgical smoothing treatment for lines, wrinkles and furrows but Botox®, the original drug made by Allergan, is licensed in the UK for treating underarm hyperhidrosis, the medical name for excessive sweating. As you say, this is often distressing and can significantly impact people’s lives. One study of women patients reported that hyperhidrosis led to concerns such as low self-esteem, worries about stained clothes and a sense of not being in control of their own lives.

Sweating is a normal bodily function, which keeps the body at the steady temperature necessary for everything to work properly. Most people sweat more when it’s hot, during exercise and also when they’re stressed or anxious. But some people sweat much more than is needed to control their body temperature, according to the support group Hyperhidrosis UK (hyperhydrosisuk.org). We recommend looking at this website as it provides lots of useful information about possible ways to mitigate the problem.

There are two types of hyperhidrosis, primary and secondary, which may affect one or two areas or large parts of the body. ‘Primary hyperhidrosis has no apparent medical cause and tends to start in adolescence or even childhood. Secondary hyperhidrosis can occur at any point, to men and women equally, as a result of a wide range of medical conditions.  These include hormone disturbances like the menopause, also obesity, thyroid disease and diabetes,’ explains Dr. Sophie Shotter, an aesthetic doctor. You are also more likely to develop hyperhidrosis if a parent has it.

Botox® is actually the brand name of a type of botulinum toxin made by the pharmaceutical company Allergan; it was the original form of the drug and became the generic name. Dr. Shotter, who is a physician trainer for Allergan, has treated patients with this problem for nearly a decade. She explains that the nerves that make us sweat seem to be more active in people with this problem, which affects some three to five per cent worldwide. Botox® works by blocking the chemical at the end of the nerves, so it turns off the sweat glands at the site where it is injected.

In Dr. Shotter’s experience, patients need one session to get a result, which kicks in from two days after. She reviews patients after two weeks. The treatment will need repeating about every six months. ‘Research shows an average 82-87% decrease in sweating,’ she says. ‘Some patients achieve complete dryness with Botox® treatment while others achieve a significant reduction to normal levels.’ Those patients will probably want to use an antiperspirant (deodorant alone only disguises any smell) and Hyperhidrosis UK has a useful list, including prescription products.

Patients report Botox® treatment in the armpit being ‘mildly uncomfortable’, also, as Dr Shotter points out, ‘any procedure with a needle can cause bruising’. Other side effects are very rare with experienced practitioners.

A small number of NHS hospitals offer this treatment but it is mostly only available privately. As with all non-surgical procedures, it’s vital to check that whoever you consult is appropriately qualified and experienced. Hyperhidrosis UK offers a Find a Doctor button , with information from a worldwide database.