What to Know About Iontophoresis for Hyperhidrosis

Medically Reviewed by Sabrina Felson, MD on July 16, 2023
4 min read

Iontophoresis is a treatment for hyperhidrosis — or excessive sweating. It involves sending a gentle electrical current through water to shut down your sweat glands temporarily. If it works for you, you’ll have to keep doing the treatments to maintain the results.

Hyperhidrosis is when you sweat a lot more than normal. It is not related to exercise or temperature. You may sweat so much you soak your clothes.

If you have hyperhidrosis, you have overactive sweat glands.

There are two types of hyperhidrosis:

  • Primary or focal hyperhidrosis — which is inherited and caused by a change in your genes
  • Generalized or secondary hyperhidrosis — which is caused by a medical condition or medicine and makes you sweat all over

Focal hyperhidrosis usually only affects your:

  • Armpits
  • Bottoms of your feet
  • Palms of your hand
  • Face
  • Lower back
  • Genitals

During iontophoresis, you’ll sit with both hands or both feet or one hand and one foot in a shallow tray filled with tap water. The machine will send a small electrical current through the water.

The treatment will take around 15 to 40 minutes depending on the machine. If you are having other parts of your body treated, your machine may use pads.

You’ll typically need to repeat the treatment three times per week until you achieve the results you want. After that, you'll have to do maintenance treatments, usually once per week.

You’ll need a prescription from your doctor to buy a plug-in device to use at home, and your insurance may cover its cost. 

If your water is too soft, you may need to add a teaspoon of baking soda to it for the iontophoresis to be effective. Soft water may not contain enough minerals and electrolytes for the current to travel through.

If plain tap water or tap water with baking soda isn't effective for you, your doctor may prescribe an anticholinergic, which is a medicine used to treat hyperhidrosis. You’ll be asked to crush this medicine and add it to the water.

Iontophoresis has been shown to be very effective in treating focal hyperhidrosis that involves the hands and feet.

In 2017, a study found that 24 out of 27 people had marked improvement in their symptoms within 2 to 4 weeks of treatments done every other day. They maintained their improvement by doing a treatment every 3 to 4 weeks. Only three people didn't respond to the iontophoresis.

Iontophoresis was first used to treat excessive sweating in 1936. Researchers don't understand exactly how iontophoresis works to stop excessive sweating.

One theory is that it disturbs the normal flow of sweat along the sweat duct. Another theory is that the iontophoresis blocks the sweat at the outer layer of the skin. 

Neither of these theories does a great job of explaining how iontophoresis works. However, it's very effective and doesn't have many side effects. Some people may get temporary blisters, itching, or dry skin. No one in the study stopped the treatments because of the side effects. 

Successful iontophoresis will depend on you. Treatments will continue indefinitely and can involve a large time commitment, especially in the beginning. Here are some tips to help you get started:

  • Before you try iontophoresis at home, have a trained health care provider show you the correct method.
  • Be prepared to feel a mild tingling sensation during the treatment.
  • You may be startled by the electrical current. It's not enough to shock you, but don't take your hands or feet out of the water.
  • Take off any jewelry you're wearing before you start treatments.
  • Cover any sore spots with petroleum jelly before you start treatment. Remember that petroleum jelly blocks the iontophoresis, so don't use more than you need.
  • If treatments dry out your skin, use a moisturizer afterward.
  • Use 1% hydrocortisone cream to treat any irritation or redness after your treatment.
  • If your treatments don't seem to be working, talk to your doctor about adding baking soda or a prescription medicine to your water.

Iontophoresis is not usually the first treatment option for hyperhidrosis. Your doctor may suggest you try other treatments before trying iontophoresis. You may also need other types of treatment if iontophoresis doesn't work for you. Some other treatment options may include: 

  • Showering more often and wearing breathable fabrics if you have mild symptoms.
  • Aluminum-based antiperspirants seal up your sweat glands. Your doctor may give you a prescription for a stronger antiperspirant than the one available over the counter.
  • Oral medicines, like anticholinergics, to make prescription antiperspirants work better, antidepressants to help with anxiety, or beta-blockers to help calm you.
  • Prescription-strength wipes to help block sweating.
  • Botox injections to stop sweat production. But, this can be expensive and may need to be repeated multiple times.
  • Microwave therapy to destroy overactive sweat glands permanently.
  • Surgery to remove your sweat glands or disconnect the nerves causing your symptoms. However, all surgeries have risks, and some people experience increased sweating in other areas after having surgery.