Botulinum Toxin for Underarm Sweating (Axillary Hyperhidrosis)

If you are constantly dealing with sweat patches, changing clothes more than once a day, or avoiding certain fabrics and colours just to hide underarm stains, you might be facing something more than just ordinary sweating. Axillary hyperhidrosis, excessive underarm sweating, can make everyday situations feel uncomfortable or even embarrassing. Social outings, work meetings, and gym sessions become sources of stress, not confidence. When regular antiperspirants and deodorants don’t help, it’s easy to feel stuck.

Botulinum toxin offers a simple, effective way to take back control. By temporarily blocking the nerve signals that trigger sweat glands, it helps reduce underarm sweating at the source, so you can go about your day without the constant worry.

Understanding Axillary Hyperhidrosis

Hyperhidrosis is a condition where the body produces more sweat than necessary to regulate temperature. In the case of primary focal hyperhidrosis, the sweating is localised, commonly affecting the underarms, palms, soles, or face, and occurs without any underlying medical condition. Axillary hyperhidrosis refers specifically to excessive sweating in the underarm area.

This condition often begins during adolescence or early adulthood and can have a significant impact on daily comfort, confidence, and overall quality of life. Many individuals experience social embarrassment from visible sweat patches, damp clothing, and concerns about body odour. 

Practical issues such as stained clothes, the need to change outfits frequently, or difficulty gripping objects (in cases involving the hands) can disrupt daily routines. The emotional toll is equally important, with many struggling with anxiety, self-consciousness, and avoiding social or physical activities for fear of noticeable sweating.

Secondary Hyperhidrosis

Unlike primary hyperhidrosis, which usually affects localised areas like the underarms or palms, secondary hyperhidrosis occurs as a result of another medical condition, medication, or external factor. It typically involves more widespread sweating and may happen during sleep (night sweats). Identifying and treating the underlying cause is key to managing symptoms effectively. Below are some common medical reasons behind secondary hyperhidrosis:

Endocrine disorders — hormonal and metabolic conditions that raise internal temperature

• Hyperthyroidism — an overactive thyroid speeds up metabolism, which can increase body heat and lead to excessive sweating.

• Diabetes mellitus — low blood sugar (hypoglycaemia) episodes may cause sudden, intense sweating, especially in insulin users.

• Menopause — hormonal shifts, particularly declining oestrogen, can trigger hot flushes and night sweats.

• Pregnancy — increased hormone levels and blood volume during pregnancy can cause noticeable changes in body temperature and sweating.

• Phaeochromocytoma — a rare adrenal gland tumour that raises adrenaline levels, causing sweating, high blood pressure, and palpitations.

• Acromegaly — excess growth hormone, often due to a pituitary tumour, can lead to enlarged sweat glands and increased perspiration.

Neurological disorders — conditions that disrupt the body’s temperature regulation

• Parkinson’s disease — can affect sweat regulation, leading to over-sweating in some areas and reduced sweating in others.

• Stroke — damage to temperature-regulating parts of the brain can cause unusual sweating patterns.

• Spinal cord injury — can impair sweating below the level of injury, with compensatory sweating above.

• Autonomic neuropathy — damage to nerves that control involuntary functions, including sweat production (common in diabetes).

Infections — both acute and chronic infections may trigger sweating through fever

• Acute infections — illnesses like influenza, pneumonia, or other febrile illnesses can cause sweating as the body cools down.

• Chronic infections — long-term conditions such as tuberculosis, HIV, malaria, or endocarditis often present with persistent sweating and fever.

Cancers — some malignancies cause systemic symptoms like night sweats

• Lymphomas and leukaemias — these blood cancers are well-known for causing unexplained night sweats.

• Carcinoid syndrome — rare neuroendocrine tumours may release hormones that cause sweating, flushing, and digestive issues.

Cardiovascular conditions — poor heart function may trigger sweat responses

• Heart failure — when the heart struggles to pump efficiently, the body may activate stress responses that result in increased sweating.

Other possible causes — additional medical or psychological factors

• Obesity — increased body mass leads to heat retention and greater exertion during movement, both of which can increase sweating.

• Anxiety disorders — persistent anxiety can heighten the body’s stress response, leading to ongoing sweating episodes.

• Gout — while primarily a joint condition, some individuals experience sweating during acute attacks.

• Substance withdrawal — alcohol or drug withdrawal (e.g. opioids) can cause symptoms such as sweating, shaking, and agitation.

How botulinum toxin helps reduce underarm sweating 

Botulinum toxin is a purified protein derived from the bacterium Clostridium botulinum. In controlled, minute doses, it works by interrupting the nerve signals that activate sweat glands. For axillary hyperhidrosis, it is typically considered a second-line treatment when topical or oral options fail to offer relief.

The underarms contain a high concentration of eccrine sweat glands, which are triggered by a chemical messenger called acetylcholine. Botulinum toxin temporarily blocks the release of this messenger, effectively switching off sweat production in the treated area. The effect is highly localised, so only the sweat glands at the injection site are affected—surrounding muscles and other nerves remain undisturbed.

What to expect during botulinum toxin treatment 

Botulinum toxin treatment for underarm hyperhidrosis is a quick, in-clinic procedure performed by a trained medical professional. Here’s how it works:

• Consultation and diagnosis — your doctor will begin with a detailed discussion of your symptoms and medical history. In some cases, a starch-iodine (Minor’s) test may be used to map the areas with the most active sweating.

• Preparation — the underarm area will be cleaned thoroughly. A topical anaesthetic cream or ice may be applied if you’re sensitive to needles, although many patients find the procedure tolerable without numbing.

• Injections — using a very fine needle, small amounts of botulinum toxin are injected into the skin in a grid-like pattern across each underarm. Typically, around 15 to 20 superficial injections are administered per side.

• Aftercare and recovery — the procedure usually takes 15–30 minutes, with no downtime required. You may notice mild redness, swelling, or tiny bumps at the injection sites, but these usually settle within a few hours.

Results and longevity

The effects of botulinum toxin don’t appear instantly. Most people begin to notice a clear reduction in underarm sweating within 2 to 7 days, with the full effect typically visible by two weeks after treatment.

The results usually last around 6 to 7 months, though this can vary slightly depending on the individual. As the nerve endings gradually regenerate, sweating may slowly return, at which point repeat treatment can be done to maintain dryness. Interestingly, some patients report longer-lasting effects after several treatment cycles, possibly due to reduced sweat gland activity over time.

Safety and potential side effects of botulinum toxin

When performed by a qualified and experienced medical professional, botulinum toxin injections for underarm hyperhidrosis are generally very safe. The procedure involves superficial injections and carries minimal risk when proper technique and approved products are used.

Common temporary side effects

These are usually mild and short-lived:

• Redness, swelling, or slight bruising at the injection sites
• Mild discomfort or a stinging sensation during the procedure
• Small bumps at injection points, which typically settle within a few hours

Less common or rare side effects

Though uncommon, the following may occur:

• Compensatory sweating — rarely, increased sweating may occur in other areas of the body. This is far less likely with underarm injections compared to surgical treatments like sympathectomy.

• Muscle weakness — there is a theoretical risk of temporary weakness in nearby muscles if the toxin spreads, though this is highly unlikely with proper technique.

• Allergic reaction — very rare, but possible, as with any injectable product.

• Mild flu-like symptoms or headache — may occur after treatment but usually resolve quickly on their own.

To reduce any risks, always choose a medical practitioner who is well-trained in botulinum toxin administration and understands the anatomy of the underarm area. Ensure that only approved and reputable brands of botulinum toxin are used.

Cost of botulinum toxin treatment in Singapore

The cost of botulinum toxin treatment for underarm sweating in Singapore depends on several factors, including the brand used, dosage required, and the clinic's expertise. It’s important to understand these variables so you can make an informed decision.

Factors that influence cost include:

• Type of botulinum toxin used — the three approved brands in Singapore are OnabotulinumtoxinA, AbobotulinumtoxinA, and IncobotulinumtoxinA. Each differs slightly in unit strength and pricing.

• Number of units needed — treatment for both underarms typically requires around 100 units or the equivalent, depending on the severity of sweating and the size of the treated area.

• Clinic reputation and doctor’s experience — more experienced practitioners and well-established clinics may charge higher fees, but this often reflects expertise and safety standards.

In Singapore, you can expect to pay between SGD $1,000 and $2,000 per session for both underarms. Your doctor will assess your condition and provide a tailored quote during your consultation.

Who should perform the botulinum toxin treatment for underarm sweating?

In Singapore, botulinum toxin injections must be administered by a registered medical doctor. It’s essential to choose someone who:

• Has specific experience treating hyperhidrosis
• Understands facial and body anatomy
• Maintains strict safety protocols and realistic expectations

Avoid unlicensed providers or unusually low-cost offers, as they may use unapproved products or improper techniques, putting your health and results at risk.

Summary 

Excessive underarm sweating, or axillary hyperhidrosis, can disrupt daily life, causing embarrassment, discomfort, and emotional distress. When topical solutions fail to provide relief, botulinum toxin offers a safe and effective alternative by temporarily blocking the nerve signals that trigger sweat production. The procedure is quick, minimally invasive, and delivers noticeable results within a week, lasting several months.

While side effects are usually mild and short-lived, treatment should always be carried out by a qualified doctor using approved products. Costs in Singapore typically range from SGD $1,000 to $2,000 per session, depending on factors such as dosage and clinic experience. 

If you are struggling with underarm sweating that doesn’t improve with over-the-counter products, schedule a consultation with APAX Medical to explore your treatment options and regain confidence in your daily life.

Frequently Asked Questions (FAQs)