An initial consultation : diagnosis and indication
A thorough medical consultation is essential before any injections. It establishes an accurate diagnosis, determines the indication, rules out contraindications and informs the patient in detail about the procedure, expected benefits and potential side effects.
The doctor :
- Assesses the nature of the hyperhidrosis (primary or secondary, localised or generalised).
- Identifies the affected areas and their impact on quality of life.
- Checks for contraindications (neuromuscular diseases, pregnancy, active skin infections, hypersensitivity to botulinum toxin).
- Answers the patient's questions, obtains informed consent and defines a personalised protocol.
In some cases, a Minor test (application of iodine and starch) may be performed to map active sweating areas, particularly if sweating is diffuse or uneven.
Preparing for the session
On the day of injection, the patient is welcomed in a strict medical setting that ensures safety and comfort. Neither hospitalisation nor general anaesthesia is required. Careful preparation precedes the injections themselves. The area to be treated is first disinfected with an antiseptic solution, usually chlorhexidine-based. Shaving may be performed if necessary to facilitate access and reduce the risk of minor skin trauma. The doctor then precisely identifies the injection points using visual markings or a skin-marking pencil, maintaining regular spacing of around one to two centimetres.
Local anaesthesia may be offered, either as an anaesthetic cream or a nerve block, to limit patient discomfort. This preparation phase, essential to successful treatment, lasts between 15 and 20 minutes on average.
Botulinum toxin injections : a precise, quick technique
Botulinum toxin is reconstituted according to the manufacturer's standards and injected in very small quantities (units) using very fine needles, intradermally (rather than subcutaneously as in treating wrinkles of the upper third of the face). The total number of injections depends on the size of the treated area, sweat gland activity and the expected response.
Underarm treatment generally involves between ten and fifteen injection points per side, corresponding to a total of 50 to 100 units.
The procedure as a whole takes an average of 30 to 45 minutes. It requires no prolonged monitoring, and patients can resume everyday activities immediately after the session unless the doctor advises otherwise.
Who performs the injections ?
Botulinum toxin injections for hyperhidrosis are a medical procedure that must be performed by a trained, experienced doctor. Unlike aesthetic botulinum toxin injections, which target the muscles responsible for expression lines, botulinum toxin for hyperhidrosis targets the sweating system. More specifically, the eccrine sweat glands in the dermis are targeted to reduce excessive sweat production.
This indication requires specific technical expertise and a thorough understanding of the skin and vascular anatomy of the treated region. Precision is essential : injections must be intradermal, with regularly and evenly distributed points to ensure uniform effectiveness throughout the area. The doctor must also adjust the dose according to sweating intensity and the size of the area to be treated, requiring an individual assessment for every patient.
Only a specifically trained doctor can guarantee this level of rigour. They can adjust protocols when treating several areas, anticipate possible side effects and account for anatomical characteristics such as thin skin or nearby deeper muscles.
Differences between botulinum toxin injections for hyperhidrosis and wrinkles
Although botulinum toxin is the same active ingredient in both indications, the injection protocol for excessive sweating is fundamentally different from the one used for aesthetic purposes.
- Injection depth : injection depth varies according to the treatment indication. For wrinkle treatment, botulinum toxin is injected intramuscularly, directly into the muscles involved in facial expressions, such as the frontalis, corrugator or orbicularis. In hyperhidrosis treatment, however, injections are superficial and intradermal, precisely where the eccrine sweat glands responsible for excessive sweat secretion are located.
- Treatment goal : the treatment goal also differs. In aesthetics, the toxin aims to reduce muscle activity to soften expression lines. In hyperhidrosis treatment, the desired effect is inhibition of sweating without affecting movement or sensation in the treated area.
- Dosage and mapping : dosage and injection-point mapping also reflect this difference. Hyperhidrosis treatment requires more injections, often around thirty per underarm, distributed evenly according to precise mapping. Total doses are generally higher than for aesthetic indications, but spread across a wider surface rather than concentrated in a muscle group.
These fundamental differences fully justify a specific medical approach to hyperhidrosis treatment, with a dedicated protocol rigorously distinct from the cosmetic use of botulinum toxin.
Can I return to work immediately after the session ?
An immediate return to work is possible after a botulinum toxin injection session for excessive sweating. This is an outpatient procedure without general anaesthesia or social downtime, requiring neither rest nor prolonged monitoring.
However, certain precautions must be followed in the hours after injection.
- Avoiding intense physical exertion is recommended, particularly when treating the soles or palms.
- Prolonged pressure on the injected region should also be avoided.
- Loose-fitting clothing (around the underarms) is preferable to limit friction.
- Except for particularly physical occupations or those involving hot, humid environments (kitchens, gyms, industrial workshops), returning to work after a session is possible immediately and without risk.
How long does a botulinum toxin injection session for excessive sweating last ?
The duration of a botulinum toxin injection session depends on whether local anaesthesia is used and whether a Minor test is performed beforehand to map areas of excessive sweating precisely. On average, a complete session lasts between 15 and 30 minutes. It begins with a preparation phase, generally lasting between 10 and 15 minutes, including thorough disinfection, marking the injection points and, if necessary, identifying active areas. The injections themselves are quick but precise, taking only a few minutes, with small doses distributed in an even grid. Finally, a short period of rest or observation after the procedure — of variable duration, often 5 to 10 minutes — may be offered, although it is not always essential.
The doctor carefully follows every stage of the protocol without rushing, ensuring safety, effectiveness and comfort throughout the session.
What do the injections feel like ?
Botulinum toxin injections for hyperhidrosis are well tolerated, although they may cause some discomfort depending on the treated area. In the underarms, patients feel a mild pinprick sensation that is well tolerated without anaesthesia.
Pain is brief and localised, requiring no pain medication after the procedure.
