Excessive underarm sweating treatment: what works

How you are assessed

Diagnosis is mostly clinical. The doctor asks when the sweating started, where it appears, whether it is on both sides and how much it limits you ^[3]. They also ask about other symptoms and your medicines, to rule out a secondary cause.

If it helps to map the area, a simple starch-iodine test (the Minor test) shows exactly where the skin sweats ^[3]. The treated area is then based on your own sweat pattern, not a template.

The treatment ladder, step by step

Treatment goes from the least invasive option upwards, according to how severe the sweating is and where it is ^{[6] [3]}.

1. Clinical-strength antiperspirants

Antiperspirants are the first-line treatment for primary focal hyperhidrosis and can help significantly ^[6]. Clinical-strength products contain higher concentrations of aluminium salts. They work better applied to dry skin at night, when the glands are less active. Some people find them irritating; using them less often, once they work, usually helps.

2. Neuromodulator injections in the armpit

If antiperspirants are not enough, the next step for the underarms is neuromodulator injections. These are prescription medicines that block the nerve signal that switches the sweat glands on. They are injected at the junction between the skin and the fat beneath it, and are a safe and effective option for focal sweating ^[6]. A systematic review for the UK found moderate-quality evidence supporting them for underarm sweating. It was the clearest conclusion of a review that otherwise found few firm answers ^[7].

How it is done: the area is marked, sometimes after a starch-iodine test. Then the doctor gives a series of small, shallow injections across the sweating area. It takes minutes per side. The sweating begins to fall within days, and the full effect takes a little longer to settle.

How long it lasts: the effect is temporary. It usually lasts several months, varies from person to person, and the treatment is repeated when the sweating returns. It is the same family of medicines used for expression lines, which we explain in anti-wrinkle injections, but used here in the skin of the armpit.

3. Other options

• Oral medication prescribed by a doctor: reserved for cases that do not respond, or for sweating over large areas ^[6]. It can cause side effects such as a dry mouth ^[3].
• Microwave and other energy devices: these heat and damage the underarm sweat glands. A systematic review of five trials with 189 patients suggested long-term benefit with mild side effects, but the studies were small and more research is needed ^[8].
• Iontophoresis: a mild electrical current through tap water. It is the main treatment for sweaty palms and soles, rather than the underarms ^[6].
• Surgery: local techniques remove or scrape away underarm sweat glands. Cutting the sympathetic nerve chain in the chest (sympathectomy) is a last resort, accepted only with the risk of compensatory sweating in other areas ^[6].

Hands and feet

Sweating of the palms and soles follows the same logic. Antiperspirants come first, then iontophoresis, which is particularly suited to these areas ^[6]. Neuromodulator injections can also be used on the hands and feet ^[6]. They are more uncomfortable there, so cold or local anaesthesia is used, and some people notice a temporary weakness in their grip.

What to expect, realistically

• Much less sweating in the treated area, not a complete absence of sweat everywhere.
• A recent review reports marked improvement in 60-70% of people with the main first- and second-line treatments ^[3].
• An effect that fades with time and needs repeating.
• Better comfort with clothes, at work and in the heat, which is often what matters most.

Overall, the research on hyperhidrosis treatments is limited, with many small studies ^[7]. A good doctor will tell you that plainly.

Risks, and who it is not for

After injections, small bruises, tenderness and redness at the injection points are common and settle in a few days. Itching, pain and irritation are the usual local reactions to treatments for sweating ^[3]. Some people notice they sweat a little more in other areas.

Neuromodulator injections are not recommended during pregnancy or breastfeeding, with a neuromuscular disorder, with an infection in the area, or before a secondary cause of the sweating has been ruled out. If you take blood thinners, bruising is more likely; tell the doctor.

How to choose where to have it

This is a medical treatment with a prescription medicine. It should be given by a registered doctor in a licensed healthcare centre, after a proper diagnosis. Be wary of anywhere that injects without asking about your health and medicines. Our guide on how to choose an aesthetic clinic in Spain covers the checks in detail.

How we approach it at Rejuvelook

At our clinic in Fuengirola, treatment for hyperhidrosis starts with a medical consultation. We confirm that it is primary hyperhidrosis and, if anything suggests another cause, we send you back to your GP first. If neuromodulator injections suit you, we map the area that sweats, treat only where it is needed and review the effect afterwards. If you live in Marbella, Mijas or Málaga, spring is a good moment to plan it, before the heat. We see patients in English or Spanish.