Research
Iontophoresis for Hyperhidrosis: What the Evidence Shows
Iontophoresis passes a mild electrical current through tap water to treat sweaty palms and soles (palmar and plantar hyperhidrosis). In a randomised sham-controlled trial, treated hands showed about a 92% reduction in sweat secretion versus about 39% for sham. In everyday clinic use, an objective response is seen in roughly 65% of patients, but the effect fades, so most people need ongoing maintenance sessions, and about 85% relapsed within six months when treatment stopped. Its exact mechanism is not fully understood. This page summarizes the verified evidence. It is educational information, 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
~92% vs 39%
reduction in palm sweat secretion (gravimetric): active vs sham iontophoresis
RCT, Ann Dermatol 2017 (N=27)
~80–85%
of palmar patients report subjective improvement within 2–4 weeks
DermNet NZ overview
65.2%
objective response in a real-world cohort (46.7% excellent, 18.5% good)
Real-world analysis (N=92)
~85%
relapsed within 6 months once maintenance treatment stopped
Real-world analysis (N=92)
not fully known
exact mechanism by which iontophoresis reduces sweating
Reviews / DermNet NZ
What iontophoresis is
Iontophoresis is a non-drug treatment for focal sweating, used mainly for the palms and soles. The hands or feet are placed in shallow trays of ordinary tap water while a device passes a low-level electrical current (often a few milliamps) through the water and skin. A typical session lasts about 20–30 minutes and is repeated several times a week at first, then tapered to a maintenance schedule.
It is generally positioned as an option to try after topical antiperspirants and before more invasive treatments, because it avoids injections, drugs, and surgery. Underarms are harder to treat this way and respond less reliably than palms and soles.
The controlled-trial evidence
The strongest single piece of evidence is a randomised, sham-controlled, single-blind trial (Ann Dermatol, 2017) in 27 people with palmar hyperhidrosis: 14 received active tap-water iontophoresis (20 minutes, five times a week for two weeks at 4.1 mA) and 13 received a sham low-intensity current. Active treatment clearly outperformed sham on every measure.
By gravimetry (weighing sweat), the mean sweat secretion rate fell by about 91.8% in the active group versus 39.1% for sham. On the starch-iodine test, 92.9% of the active group improved versus 38.5% of sham (p=0.001), and 78.6% versus 30.8% reported quality-of-life improvement (p=0.028).
| Group | Value |
|---|---|
| Sweat reduction (gravimetric), active | 91.8% |
| Sweat reduction (gravimetric), sham | 39.1% |
| Improved (starch-iodine), active | 92.9% |
| Improved (starch-iodine), sham | 38.5% |
| Quality-of-life improved, active | 78.6% |
| Quality-of-life improved, sham | 30.8% |
Source: Randomised sham-controlled trial, Ann Dermatol 2017. Chart is an original rendering of the cited data.
How it performs in everyday practice
Trial conditions are ideal; routine clinic use is messier. A real-world analysis of 92 patients treated with hospital-based tap-water iontophoresis found an objective response in 65.2%: 46.7% classed as excellent (a two-point or greater fall on the Hyperhidrosis Disease Severity Scale) and 18.5% as good, while 34.8% did not respond. Response tracked with effort: patients with excellent outcomes completed more sessions (median 20) than non-responders (median 13.5), and the number of sessions correlated with the degree of improvement.
The gap between the ~92% trial figure and the ~65% real-world figure reflects what each measures: short-term sweat reduction under a fixed protocol versus a durable, meaningful improvement graded across a varied clinic population. Both can be true at once.
Reported improvement by body area
Iontophoresis works best on the palms and soles. Underarm treatment is possible but responds less reliably. The figures below are reported subjective-improvement rates from a dermatology reference source and should be read as approximate.
| Area | Reported improvement | Source |
|---|---|---|
| Palms (palmar) | ~80–85% report subjective improvement within 2–4 weeks | DermNet NZ |
| Soles (plantar) | About 33% improved by day 14, rising to ~78% by day 20 | DermNet NZ |
| Underarms (axillary) | About 37.5% improved by day 14, rising to ~75% by day 20 | DermNet NZ |
These are reported subjective-improvement figures collated by a dermatology reference; response depends heavily on the number of sessions and adherence.
Why it works is still uncertain
Despite decades of use, the exact way iontophoresis reduces sweating is not fully established. Reviews describe several proposed mechanisms rather than one confirmed explanation: physical blockage or plugging of the sweat-duct opening, disruption of the normal electrochemical gradient the gland needs to secrete sweat, changes in local pH from hydrogen-ion accumulation, and a raised stimulus threshold in the sympathetic nerves that drive sweating. None of these is settled, and more than one may contribute.
This uncertainty matters mainly for expectations: iontophoresis is an empirically observed effect rather than a fully explained one, which is part of why protocols and results vary between people.
Maintenance, relapse, and safety
Iontophoresis controls sweating; it does not cure it. The benefit fades over weeks, so an initial run of frequent sessions is followed by maintenance treatments, often around once a week or at intervals of one to a few weeks, adjusted to how quickly symptoms return. In the 92-patient real-world analysis, about 85% of responders relapsed within six months when treatment stopped (nearly 20% within a single month), underlining that ongoing upkeep is the norm.
On safety, the treatment has a good record: the same analysis reported no compensatory sweating, burns, or electrical shocks, with only one case of mild, transient hand swelling; most people who stopped did so for practical reasons such as travel time rather than side effects. Common minor effects are skin irritation, tingling, dryness, or redness. Standard cautions apply: it is generally avoided in pregnancy and in people with a cardiac pacemaker or metal implants in the treatment path, among other conditions, so anyone considering it should confirm suitability with a clinician. This page is educational information only and not a treatment recommendation.
Methodology and limitations
This page draws on a randomised sham-controlled trial (Ann Dermatol 2017, N=27), a real-world cohort analysis (N=92), a dermatology reference source (DermNet NZ), and a treatment review. Each headline figure was traced to and confirmed on its source.
Limitations: the controlled trial is small (27 patients) and short (two weeks), so its ~92% sweat-reduction figure reflects short-term response under an ideal protocol, not long-term durable benefit. Real-world response rates are lower and depend heavily on adherence and number of sessions. Reported by-area improvement percentages are approximate and come from a reference collation rather than a single head-to-head study. The mechanism is not fully established. Nothing here is a diagnosis, an endorsement of any device or product, or medical advice.
Frequently asked questions
- How well does iontophoresis work?
- In a randomised sham-controlled trial, treated palms showed about a 92% reduction in sweat secretion versus 39% for sham. In real-world clinic use across 92 patients, about 65% had a meaningful objective response (46.7% excellent, 18.5% good). Results depend heavily on completing enough sessions.
- How many sessions does it take?
- Typically several sessions per week initially (often 6 to 15 over a few weeks) to reach improvement. In the real-world cohort, patients with excellent outcomes completed a median of about 20 sessions, more than non-responders.
- Do I need ongoing treatment?
- Usually yes. The effect fades, so maintenance sessions (often around weekly, then spaced out) are needed. In one analysis about 85% of responders relapsed within six months when treatment stopped, so iontophoresis controls sweating rather than curing it.
- Is it safe?
- It has a good safety record. A real-world analysis reported no compensatory sweating, burns, or shocks, and only one case of mild transient hand swelling. Common minor effects are skin irritation, tingling, or redness. It is generally avoided in pregnancy and in people with a pacemaker or metal implants; check suitability with a clinician.
- How does it actually stop sweating?
- The exact mechanism is not fully understood. Proposed explanations include plugging of the sweat-duct opening, disruption of the gland's electrochemical gradient, local pH changes, and a raised threshold in the sweat-driving nerves. More than one may contribute.
- Which body areas does it treat best?
- It works best on the palms and soles, where it is most commonly used. Underarm treatment is possible but tends to respond less reliably. Reported palmar improvement is around 80–85% within 2–4 weeks in one reference source.
Sources
Primary peer-reviewed studies and official sources first, then reviews and institutional framing (secondary).
- Kim DH, et al. Treatment of palmar hyperhidrosis with tap water iontophoresis: a randomized, sham-controlled, single-blind, parallel-designed clinical trial. Ann Dermatol. 2017;29(6):728–734. Full text
- Real-world cohort analysis. Hospital-based tap water iontophoresis for primary focal hyperhidrosis: treatment adherence, efficacy, and relapse (N=92). PMC12841628. Full text
- DermNet NZ. Iontophoresis: hyperhidrosis treatment overview (response rates, schedule, mechanism, cautions). DermNet NZ dermatology reference. (secondary) Reference
- Review. An overview of hyperhidrosis treatment options with an emphasis on iontophoresis as a non-invasive treatment modality. Journal of Integrative Dermatology. (secondary) Full text
How to cite this page
Sweat Explained. Iontophoresis for Hyperhidrosis: What the Evidence Shows. Published 2026-07-13; last reviewed 2026-07-13. Available at: https://sweatexplained.com/research/iontophoresis-for-hyperhidrosis-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.