Often used in facial aesthetic medicine, Botox (or botulinum toxin) is widely recognized for its effects on expression lines. It is also a major therapeutic indication in a less well-known field : excessive sweating, or hyperhidrosis.
This medical application, scientifically validated and authorized by health authorities, has profoundly transformed the management of this condition. It makes it possible to significantly reduce sweat production in targeted areas, without altering the general physiological functions of thermoregulation.
But how does Botox act precisely on the sweat glands ? What is the duration of its effect ? In which situations should it be used, and who is this treatment intended for ?
Excessive sweating, or hyperhidrosis, is a common disorder that is still too often underdiagnosed. It manifests as abundant sweating, localized (armpits, hands, feet, face) or generalized, often disproportionate to the real needs of thermoregulation. It is not related to physical effort or high temperature. It can occur at any time of day, even at rest, sometimes as early as waking.
Hyperhidrosis is not related to hygiene or emotionality, but to a dysfunction of the autonomic nervous system, which controls the sweat glands. In so-called primary forms (the most frequent), this system sends inappropriate signals, causing excessive sweat secretion in certain areas, while the rest of the body remains perfectly dry.
Faced with this often disabling discomfort, several solutions exist. But in localized forms, botulinum toxin has established itself as one of the most effective, best tolerated, and safest treatments.
Botox works by blocking the release of acetylcholine, a neurotransmitter essential for communication between nerves and the sweat glands. This neurotransmitter is the signal the nervous system sends to trigger sweat secretion.
By injecting a very small amount of botulinum toxin into the dermis, close to the nerve endings responsible for this stimulation, this signal is temporarily interrupted. The sweat gland then stops producing sweat in the treated area. The effect is local, reversible, gradual, and highly targeted.
Botox does not destroy the gland. It does not alter sweating in other parts of the body. It simply blocks, in a temporary way, the mechanism that triggers sweat secretion in the overstimulated region.
Botulinum toxin is particularly indicated for areas where sweating is localized, symmetrical, and troublesome in daily life. The most frequent indications are :
In all cases, the treatment focuses exclusively on the targeted area, without systemic effect.
One of the most common concerns expressed by patients before undergoing Botox treatment for hyperhidrosis is the fear of what is known as “compensatory sweating.” Many imagine that if sweating is stopped in one area — for example, the armpits — the body would react by sweating more elsewhere, such as on the back, thighs, or torso. In reality, this idea comes from a frequent confusion between botulinum toxin and surgery on the sympathetic nervous system.
Compensatory sweating is indeed a well-documented side effect, but it is essentially observed after certain surgical procedures, such as thoracic sympathectomy, which cuts the nerves responsible for excessive sweating. These radical procedures sometimes disrupt overall thermoregulation.
Botox, on the other hand, acts strictly locally, without altering the central command. There is no rerouting of the signal, nor overstimulation of other sweat glands. The rest of the body continues to function normally. Overall thermoregulation is ensured by all untreated areas, which is more than sufficient in the vast majority of cases.
Clinical studies confirm this: the occurrence of increased sweating elsewhere is extremely rare after treatment with botulinum toxin, and when it is reported, it is often subjective, temporary, or linked to greater self-awareness of the body’s reactions.
In summary, contrary to popular belief, Botox does not create a global imbalance in sweating. It simply suppresses a local excess, temporarily, without disrupting the rest of the body.
Hyperhidrosis can be addressed through various therapeutic approaches, but not all are equal in terms of efficacy, tolerance, or accessibility. Botox has gradually become a treatment of choice because it offers an excellent balance between safety, results, and quality of life.
Topical treatments (antiperspirants containing aluminum salts) generally constitute the first line. Their effect is limited, often insufficient in moderate to severe hyperhidrosis, and sometimes poorly tolerated (irritation, burning, contact eczema).
Iontophoresis, which involves passing a weak electrical current through water and the skin (mainly used for hands and feet), can be effective, but requires frequent and lengthy sessions. Its effectiveness varies significantly from patient to patient.
Systemic treatments, such as oral anticholinergics, can reduce sweating across the entire body, but their side effects (dry mouth, digestive disturbances, drowsiness) limit prolonged use.
Finally, surgery (sympathectomy), as mentioned earlier, remains a last-resort solution, invasive, irreversible, and associated with higher risks, particularly compensatory sweating.
In this context, Botox appears as a treatment with localized action and predictable efficacy. It does not cure hyperhidrosis, but it allows durable control of its symptoms, which can radically change the patient’s daily life.
The term “Botox” commonly refers to type A botulinum toxin, used both in aesthetics (for wrinkles) and in medicine (for therapeutic indications such as dystonias, migraines, or hyperhidrosis). While the molecule is the same, the clinical approach, doses, and objectives differ significantly.
In wrinkle treatment, Botox is injected into specific muscles to temporarily limit their contraction, producing a visible effect on facial expressions. The goal is aesthetic, the injection is very localized, and the doses used are low.
In hyperhidrosis, injections are made into the dermis, not the muscles, targeting the nerve endings responsible for sweat secretion. The doses required are higher, and the treated surface is much larger (for example, an entire armpit or the whole palm). No muscular effect or facial modification is sought here.
Moreover, in functional medicine, the treatment is guided by objective and functional markers, such as the Minor test, the intensity of reported discomfort, and mapping of active zones.
It is therefore essential to emphasize that Botox used to treat hyperhidrosis is not an aesthetic procedure, but a targeted medical act, responding to a precise indication, with a specific protocol and a clear therapeutic purpose.
It was at the beginning of the 2000s that robust clinical studies validated the efficacy of botulinum toxin in axillary hyperhidrosis, and soon after in other locations.
From 2004 onwards, the use of Botox for hyperhidrosis received official approval from health authorities (FDA in the United States, then EMA in Europe) for therapeutic use. Since then, dozens of studies have confirmed its value, particularly in dermatology, internal medicine, and aesthetic-focused medicine.
Over more than twenty years, this experience has established a rigorous, safe, and reproducible protocol, with an excellent benefit/risk ratio. Indications have expanded, techniques have been refined, and patient satisfaction has remained consistent.
Today, Botox is an integral part of the legitimate and reliable therapeutic arsenal for providing lasting relief to patients with localized hyperhidrosis.
Article written by Dr Romano Valeria
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