Botox for Excessive Sweating (Hyperhidrosis)

Sweating is controlled by the sympathetic nervous system, which is responsible for regulating your body's fight-or-flight response. When your sympathetic nervous system senses an imminent threat, it activates sweat glands in order to cool down your body and help you prepare for action. Excessive forehead sweating and facial sweating can be triggered by things like fear or anxiety, but also by exercise and hot temperatures – even if you're not aware of it happening!

Hyperhidrosis is the medical term for excessive underarm sweating and can be classified as primary and secondary. Primary hyperhidrosis can happen for no obvious reason. It normally affects both sides of your body and is more pronounced during the daytime. It usually has an effect on the scalp, face, underarms, palms and feet. Secondary hyperhidrosis occurs as a result of an underlying medical condition, which will require investigation and treatment of the underlying cause first.

A Minor’s starch iodine test may be performed prior to your treatment to determine the potential treatment area. This involves applying iodine to the area you experience excessive sweating allowing it to sweat and once it dries a small amount of starch is placed on the affected area highlighting the affected areas in dark blue colour. Experienced medical professionals who treat hyperhidrosis will inject a small amount of botulinum toxin into each affected area to control sweating.

The entire process takes about 30 minutes per area treated, though you might need more than one session if your sweating is severe or widespread over several body parts such as the forehead, back and feet.

The injected area can be numbed beforehand so you don't feel too much pain, but you may see some redness and swelling in your armpits following injectable treatments.

This will settle after a few hours and you can go back to your normal routine straight away. Results usually take two weeks to take effect and you will not need to apply deodorant when the botulinum toxin starts working.

Botox injections are not a permanent treatment for your excessive sweating problem, but it usually lasts between three to six months. If you sweat excessively, you may need to book follow-up treatment for additional injections during this time period, so be sure you are committed to using Botox to treat underarm sweating before going ahead with treatment.

Possible side effects to Botox injections and other brands of botulinum toxin are rare, but can include:

• Headaches

• Skin irritation

• Pain or bruising at the injection site

• Swelling

• Allergic reaction

• Droopy eyelids (for facial injections)

• Dry eyes or mouth

The most dangerous complications with Botox injections are double vision and difficulty breathing, but these are thankfully extremely rare.

If you experience any side effects or complications around your sweat glands, contact your practitioner immediately.

Botulinum toxin for excessive sweating is offered 'off-label' for all areas apart from under the underarms, which means that there isn't lots of research and testing confirming its effectiveness and safety. You should therefore only see experienced medical professionals who have lots of experience in performing injectable treatments and are familiar with medical conditions associated with excessive sweating.

We highly recommend that you only undergo hyperhidrosis Botox treatment with a medically-qualified professional, who will have undergone training in anatomy and physiology, as well as be accountable to a regulatory body such as the General Medical Council (GMC), Nursing and Midwifery Council (NMC) or General Dental Council (GDC).

They should also be able to advise you of the risks of injectable treatment and be confident in handling complications if they arise.

Check out our handy guide for finding a practitioner you can trust to perform Botox injections.