miraDry for Underarm Sweat: Microwave Gland Treatment

miraDry is a one-off device treatment for the armpits. It was developed for primary axillary hyperhidrosis, where sweat glands in the underarm respond to an overactive nerve signal and soak clothing in cool weather or at rest. People who are tired of repeating a treatment every few months, or of antiperspirants that sting and still fail by midday, are the group who ask about it.

Because it acts on the glands and not on the nerve, the treatment is a commitment to a change in the skin of the armpit. Sweating that began suddenly in adult life, appears over the whole body or wakes you at night has other possible causes, from thyroid change to medication, and needs a medical check before any sweat treatment. A very lean underarm with little fat between the skin and the deeper structures is also a point to raise early, for the reason described under risks.

Two kinds of gland produce underarm sweat. Eccrine glands make watery sweat, and apocrine glands, which open into hair follicles, add the protein-rich sweat that bacteria break down into odor. Both lie at the junction of the deep skin layer and the fat below it. Microwave energy is absorbed strongly by water-rich tissue, so the handpiece can deliver heat to that junction and raise its temperature enough to damage the glands.

The miraDry handpiece draws the skin up by gentle suction, which lifts the gland layer away from muscle, nerves and vessels beneath, and a chilled plate cools the surface while the energy is delivered. The treatment is laid out with a temporary grid drawn on each armpit, and the handpiece is moved square by square until the whole hair-bearing zone has been covered.

The evidence is encouraging but not strong. In an uncontrolled study, 84% of patients needed one session and 16% returned for a second; 95% reported no or minimal sweating afterward, and most temporary reactions faded within six months (Wimmer, 2025). A retrospective comparison found that microwave treatment and suction-curettage surgery both reduced sweating and odor at six and twelve months, with no significant difference in relapse or complications (Ge, 2024).

One miraDry session at the clinic is a single fee that covers both underarms in the same visit, so there is no per-side charge to add up. The local anesthetic is part of that visit. The fee is listed excluding VAT (10% VAT is added at payment).

Some people return for a second session three months later. If you want to budget for that possibility, ask for the second session to be shown on your written quote before you travel.

Heat strong enough to damage a gland also inflames the tissue around it, so short-lived reactions are part of the normal course. Report spreading redness, fever, increasing pain, or weakness or numbness in the arm or hand straight away.

• Swelling, tenderness and a burning feeling in the armpits for several days.
• Firm lumps or cord-like bands under the skin that can take weeks to months to soften.
• Numbness or tingling in the underarm or upper inner arm for a period.
• Blisters, burns or skin color change at the treated sites.
• Nerve injury in the arm, reported rarely and especially in lean patients.
• Patchy results that leave a sweating area and lead to a second session.

Two published case reports show the limits. In a lean young man, injury to the nerve network that supplies the arm left reduced fingertip sensation 12 months later, and the authors recommended lower energy and an ultrasound check of tissue depth in thin patients (Lee, 2021). In another case, the device was used on the genital and anal area, outside the underarm, and the patient developed necrotizing fasciitis with streptococcal toxic shock, a life-threatening infection (Wen, 2022). Neither report measures how frequent these events are in the underarm.