MiraDry uses microwave energy to heat and permanently destroy sweat glands in the underarms. The device delivers focused electromagnetic energy to the layer of skin where sweat glands sit, raising the temperature enough to eliminate them while a cooling system protects the skin’s surface. In clinical studies, patients saw an average sweat reduction of 82% that held steady through 12 months of follow-up.
Microwave Energy Targets Sweat Glands
The underarm contains two types of sweat glands. Eccrine glands produce the watery sweat that cools your body. Apocrine glands produce a thicker fluid that bacteria break down into body odor. Both types sit at roughly the same depth: between 1.5 and 3 millimeters below the skin surface, clustered at the boundary where the deeper layers of skin meet the fat underneath.
MiraDry works by directing microwave energy into that narrow band of tissue. Microwaves cause water molecules in the gland cells to vibrate rapidly, generating heat. This creates a focal zone of thermal destruction right where the glands are concentrated. Because the energy is calibrated to peak at a specific depth, it can reach both eccrine and apocrine glands in a single pass.
Once destroyed, sweat glands don’t regenerate. Unlike hair follicles or skin cells, the body does not replace sweat glands after they’ve been eliminated. This is why the results are considered permanent. Your underarms contain only about 2% of the body’s total sweat glands, so losing them doesn’t affect your ability to cool down.
How the Skin Surface Stays Protected
While the microwave energy heats tissue a few millimeters deep, a cooling system built into the handpiece protects the outer layers of skin. Chilled fluid flows through a chamber that sits directly against the skin during each pulse of energy, keeping the epidermis and upper dermis cool throughout treatment. This prevents burns at the surface while allowing temperatures to climb high enough to destroy glands underneath. The device also uses suction to hold the skin close to the energy source, ensuring consistent contact and uniform energy delivery across the treatment area.
What Happens During Treatment
Before the device touches your skin, the treatment area is numbed with local anesthetic. A temporary grid is applied to each underarm to map out injection sites, and roughly 31 small injections of lidocaine are administered per side. This numbing step takes several minutes and is the most uncomfortable part for most people. Once the anesthesia kicks in, you shouldn’t feel pain during the energy delivery itself, just pressure and warmth.
The clinician then moves the miraDry handpiece across the grid, delivering pulses of microwave energy to each marked spot. The full procedure for both underarms typically takes about an hour. Most patients need only one session to see significant results, though some people with more severe sweating opt for a second treatment. A third session is rarely needed.
Sweat and Odor Reduction
Clinical data paints a consistent picture. In a study of patients who received two treatments, the average sweat reduction was 82% at 12 months, nearly identical to the 83% reduction measured at 30 days. That durability matters because it confirms the glands aren’t recovering over time.
Odor improvement is equally notable. In one clinical evaluation of 31 patients, only about 13% had no noticeable underarm odor before treatment. At the six-month mark, that number jumped to 74%. Because apocrine glands are the primary source of body odor, eliminating them addresses the root cause rather than masking the symptom.
Recovery and Side Effects
Expect your underarms to be swollen, numb, and tender immediately after treatment. Swelling is the most universal side effect and can make your underarms feel lumpy or firm for several days. Ice packs and over-the-counter pain relievers are typically enough to manage discomfort during the first few days.
Most people return to desk work or light daily activities within a day or two. Exercise is a different story. Vigorous workouts, especially anything involving arm movement, are best postponed for about two weeks to let the tissue settle. Bumps, tingling, or residual numbness in the underarm area are normal and resolve gradually.
The most commonly reported side effect beyond swelling is altered sensation, including numbness and tingling, which occurred in about 10% of participants in an early randomized controlled trial. This happens because the energy can affect small sensory nerves near the treatment zone. In the vast majority of cases, sensation returns to normal within weeks. Nerve injury beyond temporary numbness is rare, reported at roughly 3% in one prospective study, and has been managed conservatively.
Cost and Number of Sessions
A single miraDry session typically costs between $1,500 and $3,000. The price varies by geographic location, provider, and whether a practice bundles in follow-up visits. Because most patients get lasting results from one treatment, the total investment often stays in that range. If a second session is needed, it’s usually performed about three months after the first, giving the tissue time to heal fully so results can be accurately assessed.
Compared to ongoing costs of prescription antiperspirants or injectable treatments (which require repeat visits every several months), miraDry’s upfront cost can be more economical over the long term for people with persistent excessive sweating. Insurance coverage varies and often depends on whether you have a formal diagnosis of hyperhidrosis and have tried other treatments first.