Oxybutynin Gel for Underarm Sweating: What Was Tested?

If underarm sweating disrupts clothing choices or work, take a symptom record and medicine list to your appointment. Ask which treatment fits your diagnosis and what would count as a worthwhile change. A product’s name alone does not answer those questions.

What did the comparison show?

In a 30-day adult trial of compounded 10% oxybutynin gel versus vehicle on opposite body sides, 53 of 61 participants completed treatment. Of 23 underarm participants, 21 completed the paired comparison. Blinded photographic starch-iodine change scores averaged 3.4 versus 2.5 (P=0.002) on a 0–4 scale, from no change to absent or nearly absent sweating. These were ordinal ratings, not collected sweat volumes. No multiplicity adjustment or confidence interval was reported.¹

Across all body sites, 42 of 53 completers identified the active side, raising masking concerns. Eleven of 23 underarm participants reported redness and itching. Pregnant or breastfeeding participants were excluded. Absorption was not measured. One author managed the compounding pharmacy. This short study cannot establish lasting benefit.¹

Which gel is being discussed?

In the US, compounded drugs are not FDA²-approved: FDA does not verify their safety, effectiveness or quality before marketing. They serve particular medical needs when an approved medicine cannot meet them. Do not mix a gel yourself or assume a different preparation reproduces this study.²

The manufacturer’s March 2019 Gelnique label concerns a different formulation for overactive bladder, with specified application sites on the abdomen, upper arms/shoulders or thighs. It does not provide an underarm sweating regimen. Its warnings include urinary retention, gastric retention, uncontrolled narrow-angle glaucoma, drowsiness, transfer through skin contact and flammability. Other anticholinergic medicines can increase adverse effects. Do not drive until its effects are known. A clinician must review the exact preparation, health conditions and other medicines.³

What should the appointment cover?

The International Hyperhidrosis Society’s⁴ February 2025 underarm guide begins with topical antiperspirants containing aluminum or zirconium salts. Further options include glycopyrronium cloth, sofpironium gel, a targeted heat patch, injections and procedures. The sequence depends on response and patient preferences; adding systemic anticholinergics to topical ones requires caution because side effects can add up. Ask about established options, irritation, cost and how long to assess a response.⁴

Arms Up offers a “Step-Up Conversation”: bring your zone-specific symptom record, compare the expected benefit and common adverse effects, and ask whether secondary causes have been excluded. Use those questions to discuss a proposed prescription before committing to it.