Botox Injections For Hyperhidrosis (Excessive Underarm Sweating)

Excessive underarm sweating or hyperhidrosis affects more than a million people in the United States. The disorder leads to diminished physical and emotional well-being, hampered personal relationships, and social stigmatization. To diagnose hyperhidrosis, the severity of social impairment caused by excessive sweating must be determined.

Botox injections for hyperhidrosis (excessive underarm sweating)

Botox injections have become a widely recognized treatment for excessive sweating of the underarms. Doctors are also using it off-label to treat palmar and plantar hyperhidrosis (excessive sweating of the hands and feet).

Mode of Action

Botox corrects excessive sweating of the underarms by blocking the secretion of chemicals that signals the activation of sweat glands. Treated patients will experience anhidrosis within 3 to 6 months. In a randomized placebo-controlled trial, patients treated with botulinum toxin reported 93% satisfaction, while the placebo group reported 30% patient satisfaction.


Botulinum toxin is not recommended to patients whose hyperhidrosis is secondary to an underlying medical disorder. It should also be avoided in patients with the following conditions:

  • Those who underwent previous surgical de-bulking of sweat glands;
  • Those who have severe blood clotting disorders;
  • Those who have active infection at the injection site;
  • Those with existing neuromuscular disorders;
  • Those who are pregnant and/or breastfeeding;
  • Those below 18 years of age.

Treatment Procedure

Using a 26G or 30G needle on a tuberculin syringe, Botox is injected subdermally into evenly distributed injections sites in the axilla. Each injection site must be at least 8mm apart. A total of 50 units reconstituted botulinum toxin per axilla is the minimum dose to correct hyperhidrosis in healthy patients.

Botox Side Effects

Common side effects related to Botox injection for axillary hyperhidrosis include:

  • Muscle weakness or tiredness;
  • Headache;
  • Neck pain;
  • Difficulty swallowing or breathing;
  • Visual disturbances;
  • Allergic reactions (rash, itching, wheezing, or dizziness);
  • Loss of bladder control.