Research
Microwave Thermolysis (miraDry) for Underarm Sweating: The Evidence
Microwave thermolysis (marketed as miraDry) is a non-invasive, energy-based procedure for underarm (axillary) sweating that uses microwave energy to heat and destroy sweat glands at the junction of the skin and fat. In the pivotal sham-controlled trial, 89% of treated participants reported a Hyperhidrosis Disease Severity Scale (HDSS) score of 1 or 2 at 30 days versus 54% of the sham group, and a separate 12-month study reported HDSS 1-2 in about 90% of participants. This page compiles the verified clinical-trial figures for effectiveness and side effects. It is general education, not medical advice.
By the Sweat Explained Editorial Team · Published 2026-07-13 · Last reviewed 2026-07-13 · Educational information, not medical advice.
Key statistics at a glance
89% vs 54%
reported HDSS 1 or 2 at 30 days: active microwave vs sham (P < .001)
Glaser 2012 RCT
69%
of treated participants still at HDSS 1 or 2 at 12 months (active group)
Glaser 2012 RCT
90.3%
at HDSS 1 or 2 and with ≥50% sweat reduction at 12 months (single-arm study, n=31)
Hong 2012
Feb 2011
FDA 510(k) clearance of the miraDry system for primary axillary hyperhidrosis
FDA 510(k) K103014
What microwave thermolysis is
Microwave thermolysis delivers microwave energy through a handpiece placed on the underarm skin. The energy is focused at the interface between the skin (dermis) and the underlying fat, where sweat glands sit, while the surface of the skin is cooled to protect it. The heat is intended to permanently destroy sweat glands in the treated area, which do not regenerate. The commercial system, miraDry, received US Food and Drug Administration (FDA) 510(k) clearance in February 2011 (510(k) number K103014) for the treatment of primary axillary hyperhidrosis, excessive underarm sweating.
Because the procedure targets the underarm specifically, the evidence below applies to axillary sweating only, not to sweating of the hands, feet, or face. Effectiveness in trials is measured mainly with the Hyperhidrosis Disease Severity Scale (HDSS), a 1-to-4 patient rating where 1-2 means sweating is never or only sometimes noticeable and tolerable, and 3-4 means it is frequently or always intolerable and interferes with activity. A drop to HDSS 1 or 2 is the standard definition of a treatment "responder."
The pivotal sham-controlled trial
The key evidence is a randomized, blinded, sham-controlled trial (Glaser 2012) of 120 adults with primary axillary hyperhidrosis, assigned to active microwave treatment (81 people) or a sham procedure (39 people). All participants had HDSS 3 or 4 and measured underarm sweat production greater than 50 mg over 5 minutes at baseline. "Responder" meant reaching HDSS 1 or 2.
| Time point | Active microwave | Sham |
|---|---|---|
| 30 days | 89% (72/81) | 54% (21/39) |
| 3 months (active group) | 74% | N/A |
| 12 months (active group) | 69% | N/A |
The 30-day difference was statistically significant (P < .001). The sham group was followed for 6 months and the active group for 12 months, so no sham comparison exists at 12 months.
Response over the first year
In the active group, the responder rate was highest soon after treatment and settled to a durable level over the first year. A separate single-arm study (Hong 2012) followed 31 adults for 12 months and reported an even higher response, which is common in smaller open-label studies.
| Group | Value |
|---|---|
| 30 days (Glaser) | 89% |
| 3 months (Glaser) | 74% |
| 12 months (Glaser) | 69% |
| 12 months (Hong, n=31) | 90.3% (Single-arm study; also 90.3% had ≥50% sweat reduction) |
Source: Glaser 2012 (RCT active arm) and Hong 2012 (single-arm). Chart is an original rendering of the cited data.
Effect on sweat volume and quality of life
Beyond the HDSS rating, the Hong 2012 study measured objective sweat reduction and quality of life in its 31 participants. At 12 months, 90.3% had at least a 50% reduction in measured underarm sweat from baseline, and 85.2% had improved by at least 5 points on the Dermatology Life Quality Index (DLQI), a validated scale where a 5-point change is generally considered clinically meaningful.
Taken together, the two studies point in the same direction: most treated people report meaningfully less underarm sweating that persists through at least the first year. The single-arm figures run higher than the randomized-trial figures, which is expected: open-label studies without a sham comparison tend to report larger effects.
Side effects reported in the trials
In the pivotal randomized trial, adverse events were generally described as mild, and all but one resolved over time. The single-arm study reported side effects in more detail: all participants had transient effects in the treated area such as swelling, discomfort, and numbness in the days after treatment. The most common specific adverse event was an altered sensation in the skin of the upper arm, reported in 12 of the 31 participants, which resolved in all of them.
Altered arm sensation is thought to reflect temporary irritation of small nerves near the treatment zone. Later case reports have also described uncommon problems such as inflammatory nodules, so side effects are not limited to what the original trials captured. Anyone considering the procedure should discuss the current risk profile with a qualified clinician.
How to read this evidence
The strongest single piece of evidence, the sham-controlled trial, shows a clear, statistically significant early benefit over a placebo procedure (89% vs 54% responders at 30 days). That sham comparison matters, because it separates the device's effect from the natural improvement and expectation effects seen in the sham group. The 12-month figures suggest the benefit is durable through the first year for most treated people.
The limits are equally important. The core trials are relatively small, industry-associated, focus only on the underarm, and follow participants for about a year, so they say little about outcomes many years later or in the hands, feet, or face. Response is not universal, some people need more than one session, and side effects, usually temporary swelling and altered sensation, are common in the short term. These figures describe average trial results, not what any one person will experience.
Methodology and limitations
This page draws on two clinical studies of the same microwave device and the device's FDA clearance record. The primary evidence is Glaser 2012, a randomized, blinded, sham-controlled trial (120 adults). Supporting durability and adverse-event detail come from Hong 2012, a smaller single-arm study (31 adults). FDA 510(k) clearance details are from the US FDA. Each figure was traced to its source and confirmed.
Limitations: the trials are small, focus only on axillary (underarm) sweating, were conducted with industry involvement, and followed participants for roughly 12 months, so long-term durability and rare harms are not well characterized here. Single-arm results (Hong) tend to be higher than randomized results (Glaser) because they lack a sham comparison. "Responder" is defined by a patient-rated scale (HDSS 1 or 2), not a laboratory cure. Nothing on this page is a diagnosis, a treatment recommendation, or medical advice; procedure decisions should be made with a qualified clinician.
Frequently asked questions
- How well does microwave thermolysis work for underarm sweating?
- In the pivotal sham-controlled trial, 89% of treated participants reported HDSS 1 or 2 (sweating tolerable) at 30 days versus 54% of the sham group, and 69% of the active group were still responders at 12 months. A separate single-arm study reported about 90% at 12 months (Glaser 2012; Hong 2012).
- Does the benefit last?
- Through the first year, yes, for most treated people in the studies: the active-group responder rate was 69% at 12 months in the randomized trial and 90.3% in a smaller single-arm study. Sweat glands do not regenerate, but the trials only followed participants for about a year, so very long-term data are limited.
- What are the side effects?
- In the trials, most side effects were temporary: swelling, discomfort, and numbness in the treated area right after the procedure. The most common specific event was altered sensation in the upper-arm skin, reported in 12 of 31 participants in one study, which resolved in all of them. Later case reports describe uncommon problems such as inflammatory nodules.
- Is it FDA cleared?
- Yes. The miraDry system received FDA 510(k) clearance in February 2011 (K103014) for the treatment of primary axillary hyperhidrosis, excessive underarm sweating. Clearance is specific to the underarm; the device is not cleared as a treatment for sweating of the hands, feet, or face.
- Does it work for sweaty hands or feet?
- The published evidence and the FDA clearance cover underarm sweating only. There is no comparable trial evidence on this page for the palms, soles, or face, so the figures here should not be applied to those areas.
- Is this a recommendation to get the procedure?
- No. This page reports what clinical studies found so the numbers are easy to check. Whether any treatment is appropriate depends on individual circumstances and should be decided with a qualified clinician.
Sources
Primary peer-reviewed studies and official sources first, then reviews and institutional framing (secondary).
- Glaser DA, Coleman WP 3rd, Fan LK, Kaminer MS, Kilmer SL, Nossa R, Smith SR, O'Shaughnessy KF. A randomized, blinded clinical evaluation of a novel microwave device for treating axillary hyperhidrosis: the dermatologic reduction in underarm perspiration study. Dermatol Surg. 2012;38(2):185-191. PMID 22289389. PubMed
- Hong HC, Lupin M, O'Shaughnessy KF. Clinical evaluation of a microwave device for treating axillary hyperhidrosis. Dermatol Surg. 2012;38(5):728-735. PMID 22452511. PubMed
- US Food and Drug Administration. 510(k) premarket notification K103014: miraDry System (Miramar Labs), cleared for primary axillary hyperhidrosis, February 2011. FDA 510(k) Premarket Notification database. FDA 510(k)
How to cite this page
Sweat Explained. Microwave Thermolysis (miraDry) for Underarm Sweating: The Evidence. Published 2026-07-13; last reviewed 2026-07-13. Available at: https://sweatexplained.com/research/microwave-thermolysis-miradry-evidence
Please cite the original studies for the underlying figures. Journalists are welcome to link to this page; the charts are original renderings of the cited data.