Microwave Treatment for Underarm Sweat: What Trials Show

If clinical-strength antiperspirant isn’t enough, one in-office option is a device that uses microwave energy to heat and destroy underarm sweat glands. US dermatologists describe it as an in-office procedure done in 1 or 2 visits, cleared by the FDA for underarm sweating.¹

The sham-controlled trial

In a US trial of adults with heavy underarm sweating, people were randomly assigned to the device or a sham treatment, without knowing which.² “Responders” were people whose sweating dropped to the two mildest levels on a standard severity scale.²

	Sham	Microwave
Responders at 30 days	54%2	89%2
At 3 months		74%2
At 12 months		69%2

Side effects were generally mild, and all but one cleared up.²

Notice the sham group: more than half felt better on a fake treatment. Subtract that, and the device’s own effect at 30 days is about 35 percentage points, which is still a clear benefit. The sham group was only followed for 6 months, so the long-term numbers have no comparison.²

Against Botox

Copenhagen dermatologists treated one underarm with Botox and the other with microwave in the same people, for a fair side-by-side test.³

• Both cut sweat throughout the study.³
• At 6 months, Botox reduced sweat more; at 1 year, they were equal.³
• Both reduced odor, but only the microwave side kept odor down at a year.³
• The microwave side also had less hair long-term.³
• 76% preferred the microwave treatment.³

How strong is the evidence?

A review of the early research found five studies with 189 patients, only one of them randomized.⁴ The results suggested lasting benefit with mild side effects, but the studies were small and the reviewers called for more on long-term safety.⁴

Side effects and cost

US dermatologists list these:¹

• Common: temporary discomfort, swelling, color change and tenderness, usually gone within 4 weeks.
• Serious, less common: burns and lasting nerve pain.
• Cost: it’s expensive and usually not covered by insurance.

For other options, see what hyperhidrosis is, underarm Botox questions and laser hair removal and underarm odor.

Try: “Clinical-strength antiperspirant isn’t controlling my underarm sweat or odor. How would microwave treatment compare with Botox for me, what are the risks, and what would it cost?”

Arms Up covers this in Chapter 10, “Hot Under Pressure,” in a section called “The Step-Up Ladder,” which lines up each treatment’s results against its placebo group. Its Fresh Log records where and when you sweat and smell, so you can judge whether a step up made a difference. See the book.