EXCESSIVE SWEATING
Hyperhidrosis is a medical condition, not a hygiene problem or a confidence issue. It affects roughly one to three people in every hundred, most of them from adolescence onward, and most of them never seek help for it.
Treatment typically lasts four to six months per course.
THIS IS NOT SOMETHING YOU HAVE TO PUT UP WITH
Most people we treat have been managing it alone for years. Layering clothes. Choosing outfits by whether they show marks. Avoiding handshakes. Keeping spare shirts at work. Turning down things they wanted to do. It is one of the conditions people are most reluctant to raise with anyone — and one of the most straightforward to treat.
15 min
320 British pounds
WHAT IS HYPERHIDROSIS?
Hyperhidrosis means sweating well beyond what the body needs to regulate its temperature. It is not caused by anxiety, being unfit, or being overweight, and it is not a failure of hygiene — though people living with it are often told all four.
Primary focal hyperhidrosis is the common form. It typically begins in childhood or adolescence, affects specific areas symmetrically — underarms, palms, soles, face or scalp — and often runs in families. There is no underlying disease causing it. The nerves that control the sweat glands in those areas are simply overactive.
Secondary hyperhidrosis is sweating caused by something else: a thyroid disorder, diabetes, an infection, the menopause, a medication, or occasionally something more serious. It tends to come on later in life, affects the whole body rather than specific areas, and often occurs at night.
This distinction matters, and it is the first thing we assess. If your sweating is generalised, started recently, wakes you at night, or comes with weight loss, fevers or feeling unwell, you need investigating by your GP before anything else. We will tell you that rather than treat you.
HOW TREATMENT WORKS
Sweat glands are switched on by a chemical messenger called acetylcholine, released by the nerves supplying them. Botulinum toxin blocks that messenger from reaching the gland. The nerve signal arrives; the instruction is not received; the gland does not produce sweat.
The effect is confined to the area injected. Your body continues to regulate its temperature normally everywhere else — this is not a whole-body change, and it does not cause compensatory sweating elsewhere in the way that surgical treatments can.
How it is done
A grid of very small injections is placed just under the surface of the skin across the treatment area. Each injection is superficial and quick.
Where it is helpful, we use a starch-iodine test to map exactly where you are sweating before we treat. An iodine solution is applied, then a fine dusting of starch. Where you sweat, the area turns dark purple. It takes a few minutes, it is entirely painless, and it means we treat where you actually sweat rather than where we assume you do.
Timings
Sweating begins to reduce within two to seven days. The full effect is usually reached at two weeks. Results typically last four to six months, and often longer in the underarms — some patients get closer to nine or twelve months once they have had a few courses. It is not a permanent cure, and treatment needs repeating.
AREAS WE TREAT
Underarms.
The most commonly treated area and the most effective. Botulinum toxin is licensed in the UK for severe primary underarm sweating that has not responded to topical treatment — meaning this specific use has been formally assessed and approved by the regulator, which is not the case for every area we treat. Treatment takes around twenty minutes and discomfort is minimal.
Hands. Highly effective, but a more uncomfortable treatment — the palms are densely supplied with nerve endings. We use techniques to minimise this and will discuss what to expect honestly beforehand. There is a small risk of temporary weakness of grip or fine pinch, which we will explain in full.
Feet.
Effective, though the thicker skin of the soles means results can be slightly less predictable than the underarms. Also uncomfortable to treat.
Face and scalp.
Useful for craniofacial sweating that ruins hair, makeup or glasses. Requires careful placement — the same muscles that produce facial expression sit in this area, and inaccurate injection can affect eyebrow position or the forehead. This is where practitioner experience genuinely matters.
Other areas including the back, chest, groin and under the breasts can be treated.
Tell us what is affecting you.
A note on the areas beyond the underarms: treatment of the hands, feet, face and scalp is an off-label use of a licensed medicine. This is lawful, well established, widely practised and supported by evidence — but it is prescribed on your practitioner's clinical judgement rather than under the product's licence, and we will explain that as part of your consent.
BEFORE YOU CONSIDER INJECTIONS
We are not going to pretend injections are the only option, or that they should be your first.
Prescription-strength antiperspirants.
Aluminium chloride preparations are considerably stronger than anything on the high street and work well for a good number of people. Applied correctly — to completely dry skin, at night — they are effective, cheap and worth trying properly first. Applied wrongly, they irritate and get abandoned, which is what usually happens.
Oral medication.
Anticholinergic tablets reduce sweating throughout the body. They work, but side effects — dry mouth, blurred vision, constipation — mean many people stop. Usually a GP conversation.
Your GP and the NHS.
Severe hyperhidrosis can be treated on the NHS, including with botulinum toxin in some areas, and you may be entitled to that. Access varies considerably and waiting times can be long — but you should know the route exists, and if we think it is the better option for you we will say so.
Surgery.
Endoscopic thoracic sympathectomy is a last resort for severe cases, and it carries a real risk of compensatory sweating elsewhere on the body that can be worse than the original problem. It is not something to approach lightly.
Where injections fit: for most people, after topical treatment has been tried properly and failed, and where the sweating is affecting daily life. That is the point at which it is worth doing.
WHAT TO EXPECT
Your consultation.
A face-to-face appointment in clinic with us at least 48 hours before treatment. We take a full history, establish whether this is primary or secondary hyperhidrosis, discuss what you have already tried, and decide together whether treatment is appropriate.
Botulinum toxin is a prescription-only medicine and cannot be prescribed without this.
Treatment day.
Mapping if we are using it, then the injections themselves. Underarms take around twenty minutes; hands and feet longer. You can drive afterwards and return to work.
Afterwards.
Some redness and small bumps at the injection points, settling within a few hours. Mild tenderness for a day or two. Occasional bruising. No exercise, saunas or hot baths for 24 hours, and no antiperspirant on the treated area that day.
The results.
Reduction starting within a week, full effect at three weeks. Most people describe it as the first time in years they have not thought about it — which is, in the end, the point.
Common side effects: injection site discomfort, redness, small bumps, mild bruising, occasional headache.
Less common: a slight increase in sweating elsewhere as the body adjusts, temporary muscle weakness near the treated area, and — where the hands are treated — temporary reduction in grip strength.
Rare: infection at an injection site, allergic reaction, and spread of effect beyond the treated area causing muscle weakness. Your practitioner will go through all of this and the MHRA warning on distant spread before you consent.
FAQ
How do I know if I have hyperhidrosis rather than just sweating a lot?
The usual markers are sweating that happens without heat or exertion, affects specific areas symmetrically, began in your teens or earlier, occurs at least once a week, and interferes with daily activities. If you change clothes during the day, avoid certain fabrics or colours, or have adjusted your life around it, that is not ordinary sweating.
Is this a medical treatment or a cosmetic one?
Medical. Severe underarm hyperhidrosis is a licensed indication for botulinum toxin in the UK, meaning it has been formally assessed and approved by the regulator for this use. It is a recognised condition with a recognised treatment.
How long does it last?
Four to six months typically, often longer in the underarms — some patients reach nine to twelve months after several courses. Hands and feet tend toward the shorter end.
Does it hurt?
The underarms are very tolerable — most people are surprised how quick and easy it is. Hands and feet are more uncomfortable because of the density of nerve endings, and we will be honest with you about that and use what we can to minimise it.
Will I sweat more somewhere else?
Not in any significant way. Some people notice a marginal increase elsewhere as the body adjusts. This is quite different from the compensatory sweating that can follow surgical sympathectomy, which can be severe.
Is it safe to stop sweating in one area?
Yes. Your underarms account for a very small proportion of your body's total sweating capacity, and temperature regulation is unaffected everywhere else.
Can I still use antiperspirant?
Most people find they no longer need it. You can use it if you prefer, but not on the day of treatment.
Will my GP do this on the NHS? Possibly, for severe cases. Availability and waiting times vary considerably by area. It is worth asking, and we will tell you if we think that is the better route for you.
Do I need a consultation before treatment?
Yes, face to face in clinic, at least 48 hours beforehand. This is a prescription-only medicine and cannot lawfully be prescribed without a proper in-person assessment.
Will I definitely be treated?
No. If your sweating pattern suggests an underlying cause, we will ask you to see your GP first. If you have not yet tried topical treatment properly, we may suggest that before injections. And if it is not appropriate for you, we will say so.
Can I have this if I am pregnant or breastfeeding?
No. Treatment is not given in pregnancy or while breastfeeding.
How much does it cost?
Costs depend on the area and the amount required, and are confirmed at your consultation. Your consultation fee is deducted from the cost of treatment if you go ahead.
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Do you treat under-18s?
No. All treatments at Sebastian Rose are for adults only, without exception.
BOOK YOUR CONSULTATION
If sweating is affecting how you dress, how you work, or what you are willing to do, it is worth a conversation. We will assess you properly, tell you honestly whether treatment is right for you, and explain what else might help if it is not.
Consultations are face to face, in clinic, in Cardiff.
0800 772 0137 · 39 Charles Street, Cardiff, CF10 2GB
