How Optune Gio works


Understanding Optune Gio

Optune Gio may help slow down or stop cancer cells from dividing, destroying some cancer cells completely.

Osmond, an Optune Gio user and Patient Ambassador, and his wife

How Optune Gio works

Optune Gio works by creating Tumor Treating Fields (TTFields). TTFields are electric fields that help slow down or stop cancer cell division and may destroy some cancer cells completely. See how TTFields work, below.

With Optune Gio, TTFields therapy is delivered right into the area of your body where the cancer is located, using 4 adhesive patches called transducer arrays. TTFields are specifically targeted; they have not been shown to significantly affect healthy cells.

How TTFields work

GBM cells divide and multiply

Usually, an untreated tumor continues to grow larger when GBM cancer cells divide and create more cells. When a GBM cell divides, it forms an hourglass shape and pulls apart into 2 identical cells.

TTFields interfere with GBM cancer cell division

Optune Gio uses TTFields, which are electrical fields that may stop cancer cells from pulling apart. This helps slow tumor growth. Additionally, Optune Gio may even destroy existing cancer cells.


Cells are sensitive to different frequencies. TTFields are tuned to a frequency that specifically targets GBM cancer cells.

Osmond is an Optune Gio user and Patient Ambassador

Chalk Talk: How Optune Gio Works

Watch the video to see how Optune Gio helps slow down and stop GBM cancer cells from dividing.

Possible side effects
Learn about Optune Gio safety
Results with Optune Gio
See the results
Talk to your doctor
Get a discussion guide

Important Safety Information

What is Optune Gio® approved to treat?

Optune Gio is a wearable, portable, FDA-approved device indicated to treat a type of brain cancer called glioblastoma multiforme (GBM) in adult patients 22 years of age or older.

Newly diagnosed GBM

If you have newly diagnosed GBM, Optune Gio is used together with a chemotherapy called temozolomide (TMZ) if:

  • Your cancer is confirmed by your healthcare professional AND
  • You have had surgery to remove as much of the tumor as possible

Recurrent GBM

If your tumor has come back, Optune Gio can be used alone as an alternative to standard medical therapy if:

  • You have tried surgery and radiation and they did not work or are no longer working AND
  • You have tried chemotherapy and your GBM has been confirmed by your healthcare professional

Who should not use Optune Gio?

Optune Gio is not for everyone. Talk to your doctor if you have:

  • An implanted medical device (programmable shunt), skull defect (missing bone with no replacement), or bullet fragment. Optune Gio has not been tested in people with implanted electronic devices, which may cause the devices not to work properly, and Optune Gio has not been tested in people with skull defects or bullet fragments, which may cause Optune Gio not to work properly 
  • A known sensitivity to conductive hydrogels (the gel on the arrays placed on the scalp like the ones used on EKGs). When Optune Gio comes into contact with the skin, it may cause more redness and itching or may rarely cause a life-threatening allergic reaction

Do not use Optune Gio if you are pregnant or are planning to become pregnant. It is not known if Optune Gio is safe or effective during pregnancy.

What should I know before using Optune Gio?

Optune Gio should only be used after receiving training from qualified personnel, such as your doctor, a nurse, or other medical staff who have completed a training course given by Novocure®, the maker of Optune Gio.

  • Do not use any parts that did not come with the Optune Gio Treatment Kit sent to you by Novocure or given to you by your doctor
  • Do not get the device or transducer arrays wet
  • If you have an underlying serious skin condition on the scalp, discuss with your doctor whether this may prevent or temporarily interfere with Optune Gio treatment

What are the possible side effects of Optune Gio?

Most common side effects of Optune Gio when used together with chemotherapy (temozolomide, or TMZ) were low blood platelet count, nausea, constipation, vomiting, tiredness, scalp irritation from the device, headache, seizure, and depression. The most common side effects when using Optune Gio alone were scalp irritation (redness and itchiness) and headache. Other side effects were malaise, muscle twitching, fall and skin ulcers. Talk to your doctor if you have any of these side effects or questions.


Please click here for the Optune Gio Instructions For Use (IFU) for complete information regarding the device’s indications, contraindications, warnings, and precautions.

Novocure Websites

This website is intended for people seeking information on Optune Gio.

On this site, videos and images identified as Optune Gio users, caregivers, or healthcare professionals depict actual patients, caregivers, and healthcare professionals.

Patient images reflect the health status of the patients at the time each photo or video was taken.


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MyLink, MyNovocure, Novocure, and Optune Gio are registered trademarks of Novocure GmbH.

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US-OPG-00063 v2.0 March 2024