Hyperhidrosis Injections

Hyperhidrosis is excessive sweating beyond what the body requires to regulate its temperature. It most often affects the underarms, palms, soles, and scalp, and for many people it is persistent rather than situational. Injectable neuromodulators — the same botulinum toxin type A used for expression lines — offer a well-established, non-surgical way to reduce sweating in a treated area. Botox is approved by Health Canada and the FDA for severe primary axillary (underarm) hyperhidrosis.

Sweat glands are activated by a nerve signal carried by acetylcholine. Injected just beneath the skin in small, evenly spaced amounts across the treatment area, a neuromodulator temporarily blocks the release of that signal, so the glands in that area are not prompted to produce sweat. The glands themselves are left intact — the effect is on the signal reaching them, which is why it wears off and can be repeated. Some practitioners use a starch-iodine test beforehand to map exactly where sweating is most active.

A session takes roughly twenty to thirty minutes depending on the area. The injections are shallow and numerous; topical numbing or ice is commonly used, particularly for palms and soles, which are more sensitive than underarms. There is no recovery period and you can return to your day immediately. Mild tenderness or small bumps at the injection sites are typical and settle within a few hours.

Sweating begins to reduce within two to seven days, with the full effect around the two-week mark. For underarms, results commonly last four to six months, though this varies considerably between individuals; palms and soles tend to be shorter. The effect is temporary by design — when it fades, the treatment can be repeated. Your practitioner will help you plan a cadence, and many people find they treat ahead of summer or a specific season rather than year-round.

This treatment suits people whose excessive sweating is not adequately controlled by clinical-strength antiperspirants and who want a non-surgical option with no downtime. It is not appropriate for everyone — a practitioner at a Vos Collection clinic will review your medical history, confirm the sweating is primary rather than a symptom of another condition, and discuss whether injections or a device-based approach is the better fit for you.