Research
Topical Glycopyrronium for Sweating: The Trial Data
Topical glycopyrronium tosylate is an anticholinergic wipe (brand name Qbrexza) that the FDA approved in 2018 for primary axillary (underarm) hyperhidrosis. Its approval rested on two near-identical phase 3 trials, ATMOS-1 and ATMOS-2. In the pooled data, 59.5% of people using the drug reached a meaningful improvement in a daily sweat-severity diary versus 27.6% on vehicle. The trade-off is a set of predictable anticholinergic side effects: dry mouth was the most common. This page summarizes the verified trial figures. 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
59.5% vs 27.6%
reached a ≥4-point improvement on the Axillary Sweating Daily Diary (drug vs vehicle), pooled ATMOS-1/2
Glaser 2019, JAAD
2018
year the FDA approved topical glycopyrronium (Qbrexza) for underarm hyperhidrosis
FDA / DailyMed label
24.2% vs 5.6%
dry mouth on drug vs vehicle across the two trials
Qbrexza FDA label
6.8% vs 0%
mydriasis (dilated pupils) on drug vs vehicle
Qbrexza FDA label
4 weeks
double-blind treatment duration, applied once daily to each underarm
Glaser 2019, JAAD
What was tested, and how
ATMOS-1 and ATMOS-2 were replicate phase 3 trials: randomized, double-blind, and vehicle-controlled, each running four weeks. Adults and adolescents with primary axillary hyperhidrosis were randomized 2:1 to glycopyrronium tosylate or a matching vehicle (the same cloth without the active drug), applied once daily to each underarm. The pooled safety population was 459 people on the drug and 232 on vehicle.
A note on the numbers you will see: the trials describe the active ingredient as glycopyrronium tosylate 3.75% (the salt), while the FDA label lists the product strength as glycopyrronium 2.4% (the base equivalent). These refer to the same product measured two different ways, not two different strengths.
Two co-primary endpoints were used. The first was patient-reported: the proportion of people reaching at least a 4-point improvement on Item 2 of the Axillary Sweating Daily Diary (ASDD), an 11-point sweat-severity scale. The second was objective: the change in gravimetric sweat production, which weighs how much sweat is collected over five minutes.
The headline efficacy result
In the pooled data, more than twice as many people on glycopyrronium reached the patient-reported responder threshold compared with vehicle. Note the sizable vehicle response (over a quarter of people improved on the inactive cloth), which is why a controlled comparison matters.
| Group | Value |
|---|---|
| Glycopyrronium tosylate | 59.5% |
| Vehicle | 27.6% |
Source: Glaser DA, et al. J Am Acad Dermatol 2019;80(1):128–138. Chart is an original rendering of the cited data.
The objective sweat measurement
On the objective co-primary endpoint, glycopyrronium beat vehicle but the absolute gap was modest. Gravimetric sweat production fell by about 107.6 mg per 5 minutes on the drug versus 92.1 mg per 5 minutes on vehicle (a statistically significant difference, P < .001). As with the diary result, the vehicle group also improved substantially. The clearer signal of benefit came from the patient-reported severity scale rather than the raw milligram change.
This pattern (a real drug effect layered on a large vehicle/placebo response) is common in hyperhidrosis trials and is a reason to weigh the controlled difference rather than the single-arm number.
Anticholinergic side effects on the label
Glycopyrronium is an anticholinergic, so even applied to the skin it can produce systemic anticholinergic effects. The table below is the pooled adverse-reaction table from the FDA label for the two trials, drug versus vehicle. Dry mouth was by far the most common.
| Adverse reaction | Glycopyrronium (N=459) | Vehicle (N=232) |
|---|---|---|
| Dry mouth | 24.2% | 5.6% |
| Mydriasis (dilated pupils) | 6.8% | 0% |
| Oropharyngeal pain | 5.7% | 1.3% |
| Headache | 5.0% | 2.2% |
| Urinary hesitation | 3.5% | 0% |
| Vision blurred | 3.5% | 0% |
| Nasal dryness | 2.6% | 0.4% |
| Dry throat | 2.6% | 0% |
| Dry eye | 2.4% | 0.4% |
| Dry skin | 2.2% | 0% |
| Constipation | 2.0% | 0% |
Local skin reactions were also reported and were similar between arms: erythema 17.0% vs 16.9%, burning/stinging 14.1% vs 16.9%, pruritus 8.1% vs 6.1% (drug vs vehicle).
Longer-term safety signal
A separate open-label safety trial (in which everyone knew they were using the active drug over a longer period) reported dry mouth in 16.9%, blurred vision in 6.7%, and mydriasis in 5.3% of participants. The FDA label also warns that transient blurred vision can occur, and describes post-marketing reports of dilated pupils, unequal pupil size, and blurred vision after accidental eye contact, for example when someone touched the eye area after using the cloth. These effects were generally temporary.
What the evidence does and doesn't say
In plain terms: two phase 3 trials show that topical glycopyrronium reduces underarm sweat severity more than an inactive cloth, with roughly 60% of users reaching a meaningful improvement on a daily diary versus about 28% on vehicle. That is a genuine, FDA-reviewed effect. It is not a cure, the benefit is partial, and a notable share of the improvement in trials also appeared in the vehicle group.
The evidence is specific to the underarms: that is the only body area these trials studied and the only approved use. It does not establish results for sweaty hands, feet, or face. And because glycopyrronium is an anticholinergic, side effects such as dry mouth, blurred vision, and dilated pupils are expected rather than rare. Whether the benefit is worth those effects is an individual decision to make with a clinician who can review your history and other options.
Methodology and limitations
Efficacy figures are taken from the primary phase 3 publication (Glaser DA, et al. J Am Acad Dermatol 2019;80[1]:128–138; PMID 30003988), which reports pooled ATMOS-1 and ATMOS-2 results. Safety figures and approval details are taken directly from the current FDA prescribing information (DailyMed). Each figure was traced to its source and confirmed.
Limitations: the two trials were short (4 weeks of double-blind treatment), studied only the underarms, and enrolled people with primary (not secondary) axillary hyperhidrosis. The vehicle response was large, so single-arm percentages overstate the drug's net effect; the controlled difference is the more meaningful figure. Adverse-event rates come from these specific trial populations and dosing. Nothing here is a diagnosis, a recommendation, or medical advice; treatment decisions belong with a prescribing clinician.
Frequently asked questions
- How well did topical glycopyrronium work in the trials?
- In the pooled ATMOS-1 and ATMOS-2 phase 3 trials, 59.5% of people using glycopyrronium reached at least a 4-point improvement on a daily underarm sweat-severity diary, versus 27.6% on the inactive vehicle (P < .001). The benefit is real but partial, and the vehicle group also improved substantially.
- When was it approved and for what?
- The FDA approved topical glycopyrronium (Qbrexza) in 2018 for primary axillary hyperhidrosis, excessive underarm sweating, in adults and children 9 years and older. It is applied once daily to both underarms. It is not approved for the hands, feet, or face.
- What are the main side effects?
- Because it is an anticholinergic, the common effects are dryness-type reactions. In the trials, dry mouth affected 24.2% on the drug versus 5.6% on vehicle, mydriasis (dilated pupils) 6.8% versus 0%, and blurred vision and urinary hesitation about 3.5% each versus 0%.
- Why is the vehicle (placebo) response so high?
- Large vehicle responses are common in hyperhidrosis trials: over a quarter of people improved on the inactive cloth. That is exactly why a controlled comparison is used: the meaningful figure is the difference between drug and vehicle, not the drug arm's number alone.
- Does it work for sweaty hands or feet?
- The phase 3 trials only studied the underarms, and that is the only approved use. These results do not establish how well topical glycopyrronium works for the hands, feet, or face.
- Is this a recommendation to use it?
- No. This page reports what the trials and FDA label show. Whether topical glycopyrronium is appropriate (weighing its partial benefit against anticholinergic side effects and other options) is a decision to make with a clinician.
Sources
Primary peer-reviewed studies and official sources first, then reviews and institutional framing (secondary).
- Glaser DA, Hebert AA, Nast A, Werschler WP, Green L, Mamelok R, Drew J, Quiring J, Pariser DM. Topical glycopyrronium tosylate for the treatment of primary axillary hyperhidrosis: Results from the ATMOS-1 and ATMOS-2 phase 3 randomized controlled trials. J Am Acad Dermatol. 2019;80(1):128–138.e2. PMID 30003988. PubMed
- US Food and Drug Administration / DailyMed. QBREXZA (glycopyrronium) cloth, 2.4%, for topical use: full prescribing information (Indications, Dosage, Adverse Reactions). Initial U.S. approval 2018. DailyMed, National Library of Medicine. DailyMed label
How to cite this page
Sweat Explained. Topical Glycopyrronium for Sweating: The Trial Data. Published 2026-07-13; last reviewed 2026-07-13. Available at: https://sweatexplained.com/research/topical-glycopyrronium-for-sweating-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.