When temperatures rise, most of us sweat more, as it’s the body’s way of seeking relief from the heat and cooling down. But sometimes, sweating can become excessive, a condition that can range from “mild dampness to severe dripping and can result in substantial impairment in quality of life,” according to a 2016 study published by the National Institutes of Health. People who experience excessive sweating, according to cosmetic dermatologist Michele Green, most likely “suffer from a condition called hyperhidrosis. In these patients, the nerves which signal the sweat glands to function are hyperactive and cause an excessive amount of sweat.” Hyperhidrosis is classified as a skin condition resulting from overactivity of sympathetic nerves.

The aforementioned study estimates that over 15 million people in the U.S. experience excessive sweating and notes that there are probably even more people who suffer from the condition but do not report it. Current findings indicate that people with excessive sweating might not know the condition is indeed a medical concern nor that there are treatment options available. One such treatment is the injection of BOTOX®, which garners temporary relief from excessive sweating. “By injecting injecting BOTOX®directly into the areas which cause sweating, such as your underarm or palms,” explains Green, “these overactive nerves are [rendered unable to] signal the nerves in your sweat glands to fire, and hence block the release of sweat in the injected areas.”

Ahead, a cosmetic dermatologist and aesthetic nurse explain how BOTOX® is used to treat excessive sweating, and everything you need to know about the treatment procedure.

Sweating is normal. In fact, it’s essential: Humans need to sweat in order to regulate body temperature.

But some people sweat much more than is needed. We spoke with University of Minnesota Health Dermatologist Lori Fiessinger, MD, who practices both medical and cosmetic dermatology, to learn about BOTOX® injections for excessive sweating.

Hyperhidrosis, more commonly known as excessive sweating, can significantly affect a person’s quality of life. In some cases, problematic sweating is limited to one area of the body, such as the underarms or feet, a condition called focal hyperhidrosis. Other cases are more generalized, with sweating over large areas of the body. The most common areas affected by hyperhidrosis are the scalp, underarms, hands, feet and groin area.

“Excessive sweating can significantly affect a person’s life,” Fiessinger said. “It can be embarrassing and socially isolating, and many people find the condition quite upsetting.”

BOTOX®—often associated with cosmetic wrinkle reduction—is also a particularly effective treatment for focal hyperhidrosis. BOTOX® injections use botulinum toxin to block the nerve signals responsible for sweating, stopping the sweat glands from producing too much sweat. Retreatment is typically needed in four to six months, as the nerves regenerate. Over time, however, patients can go longer between treatments.

What is BOTOX®?

BOTOX® is a neurotoxin made from the microbes that cause botulism (a kind of food poisoning). But don’t worry, it’s safe if used appropriately by a medical professional.

BOTOX®is most well known as a cosmetic treatment to smooth facial wrinkles by temporarily paralyzing muscles. Doctors also use BOTOX® to treat neuromuscular conditions like migraine, muscle spasms, and hyperhidrosis, a condition characterized by abnormal and excessive sweating.

You may be a candidate for BOTOX® if your sweating fails to improve with prescription antiperspirants. BOTOX® has been FDA-approved for people who sweat excessively from their armpits. It may also be used “off-label” to reduce sweating in other areas, such as the hands, feet, and face.

What Is BOTOX® for Sweating?
“Patients who suffer from excessive sweating suffer from a condition called hyperhidrosis,” explains Green. Because BOTOX® is a neurotoxin, its “mechanism of action,” according to Green, is that it “blocks the nerves which are responsible to activating sweat glands.” BOTOX® contains a protein called onabotulinumtoxinA, which effectively prevents the sweat glands from excreting sweat.

People who are best suited for this procedure are, according to Green, “healthy individuals who have used prescription antiperspirants without success and are looking for a better way to have long-term relief from sweating.” According to Dillenberg, contraindications for the procedure include but are not limited to “pregnant and breastfeeding people, people with allergies to neurotoxins, hemorrhagic conditions, autoimmune disease, and neuromuscular disorders.”

Benefits of BOTOX® for Sweating

Studies indicate that BOTOX® is highly effective for reducing excessive sweating, and as such, the treatment is usually at least partially covered by insurance. You may have to undergo previous treatments (like the use of prescription-strength antiperspirants) in order for your insurance to deem the treatment a necessary medical option.

When injected into a patient’s underarm, BOTOX® can offer relief from sweating for up to five months. “BOTOX® also helps considerably in treating sweaty palms, soles of feet, and foreheads,” says Green. Studies indicate that BOTOX® can be effectively used to treat excessive sweaty palms as well as excessive forehead sweat. Currently, BOTOX® is most prevalently used to treat excessive underarm perspiration.

How do BOTOX® injections work to treat sweating?
BOTOX® injections block the release of the neurotransmitter acetylcholine, which binds with your sweat glands to signal the release of sweat.

Normally, your nervous system activates your sweat glands when your body temperature rises. This is how your body automatically cools itself. In people with hyperhidrosis, however, the nerves that signal the sweat glands are overactive.

When you receive BOTOX® injections directly into the area of your body that commonly sweats, your overactive nerves are essentially paralyzed. When your nerves can’t signal your sweat glands, you don’t sweat. However, BOTOX® only prevents sweating in the specific area where it’s injected.

Where is BOTOX® used on the body to treat sweating?
Currently, BOTOX® has only been approved for the treatment of underarm sweating. Studies have found varying results, but there’s ample evidence that BOTOX® can reduce armpit sweat production by more than 50 percent for at least 6 months.

Doctors use it “off-label” to treat other areas of the body.

  • Palms. A limited amount of research has investigated the effectiveness of BOTOX® for palm sweating. Studies have found that BOTOX® may reduce sweating by roughly 25 to 50 percent for 3 weeks to 6 months.
  • Face. A very limited amount of research has found that BOTOX® may help treat facial sweating. Studies have found BOTOX® could reduce facial sweating for 5 to 6 months with the most common side effect being paralysis of muscles in the forehead.
  • Soles of feet. BOTOX® may help control sweating on the soles of the feet, however few studies have been done. In a small 2018 study, 73 percent of a group of people ages 12 to 17 were satisfied with their results.


How to Prepare
To minimize bruising, it’s best to avoiding aspirin, Motrin, Aleve, fish oil, or any other blood thinners for one week prior to the injections, recommends Green.

If the injections are in the axillae (armpits), avoid laser hair removal or shaving for two days before your appointment. Dillenberg notes that the procedure works best on clean-shaven areas, so it is advisable to shave your underarms before the treatment, and make sure you do so 48 hours prior to the procedure.

Finally, because these injections can be painful (especially if you’re treating sensitive underarm areas), Green recommends patients apply a topical numbing cream containing lidocaine one hour before the injections.

BOTOX® injections are a simple and quick procedure done right in your doctor’s office. Doctors typically ask that you wear a short-sleeved shirt and avoid shaving your armpits for 2 or 3 days prior to your appointment. If you take blood thinners, your doctor may ask you to stop for a few days before your injections to prevent bruising. Tell your doctor about any medications you’re taking and don’t stop taking any medications unless your doctor tells you to.

Your doctor may also recommend wearing a dark-colored shirt to avoid getting ink on it.

What to Expect During Treatment

During the treatment, a fine needle is used to inject BOTOX® into the treatment area. Your physician or nurse will use multiple small injections, performed in a grid-like pattern. In order to determine the pattern, your physician or nurse will first need to determine the exact location of the overactive sweat glands.

“We start by properly cleaning the underarms,” explains Dillenberg, “and then apply iodine solution (a topical antiseptic). After the solution dries, we then dust on baby powder and have the patient hold their arms tightly to their body to stimulate sweating in the area. Sometimes we even ask the patient to jump up and down, anything to get the sweating going! After about 10 minutes, we then look at the underarms to see where the darkest spots from the iodine solution are.” She explains the darkest spots denote the exact target of the overactive sweat glands. Once the target spots are properly cleaned off, your physician or nurse will begin the injections.

According to Dillenberg, “there are a few small injections that feel like little pinches during the procedure.” Post procedure, she says, there should be no lingering pain, although “there can be some injection site redness or bruising.”

Side Effects of BOTOX® for Sweating

There are very few side effects to this treatment. Common ones, according to Green, “are localized pain or bruising at the site of injection. More rare are headaches, flu-like symptoms, or muscle weakness in the body.”

Aftercare

Aftercare for BOTOX® injections to treat excessive sweating is nominal. “After the injections, there is minimal downtime and the area heals quickly. You can resume normal activities immediately after treatment,” says Green. Dillenberg adds that for “12 hours post procedure, patients should avoid applying anything to their underarms (including deodorant or antiperspirant). Patients should also avoid vigorous exercise and extreme heat for about 48 hours, including hot tubs, steam rooms, and saunas.”

As for when to expect results, both our experts say you can feel a difference in just a couple days post-treatment. “The results begin to take effect in a few days,” says Green, “but the full effects take up to two weeks. The positive effects of the procedure can last up to five months in duration.”

How long does BOTOX® for sweating last?

The effects of BOTOX® are temporary, which means you’ll need more injections in the future. For underarm sweating, booster injections are generally needed every 7 to 16 months. Results may not last as long for the hands and feet, and you may need to repeat your treatment after about 6 months.

How effective is BOTOX® for hyperhidrosis?

When used to treat underarm excessive sweating, BOTOX® has been shown to result in an 82-87% decrease in sweating. Results start to be noticeable approximately 2 to 4 days after treatment with the full effects usually noted within 2 weeks.