Managing alarms


What causes Optune Gio alarms to go off?

Optune Gio is designed to alert you if treatment is not being delivered. Find out what can cause your device’s alarm to go off and how to manage it.

Gill, an Optune Gio user and Patient Ambassador

If you hear an alarm, an issue may be occurring. Explore the possibilities below:

Are the arrays in good contact with your skin?

If not, using tape or elastic tubular dressing can ensure good contact with the scalp.


When was the last time you changed your arrays?

Arrays should be changed at least 2 times per week (every 4 days at most).


Is there hair stubble beginning to grow?

Even if there is a small amount of hair growth, a new set of arrays should be applied after shaving. See Scalp Care Guide for more tips.


Are the arrays too warm?

Direct sunlight should be avoided. A breathable head covering could be helpful, as well as a fan. If sweat causes arrays to shift, they should be changed.


Get 24/7 personalized support. Call MyNovocure® at 1-855-281-9301. Email MyNovocure at

It’s important to know that MyNovocure cannot provide medical advice. To make sure you receive proper support, be sure to ask your doctor any treatment questions you may have.


If you turn Optune Gio on without pressing the TTFields button, an alarm will sound after 10 minutes.

Press the TTFields button once to silence the alarm and twice to start therapy.

Osmond, an Optune Gio user and Patient Ambassador

What to do if your
Optune Gio device’s alarm goes off

Answer the following questions to help you identify the alarm that’s going off and what it means.

Question 1

What does the alarm sound like?

Take the Optune Gio
Troubleshooting Tips brochure with you on the go.

Get an Optune Gio travel checklist to help you prepare for your trip.

Download the brochure
Caring for your skin
Get skin care tips
Optune Gio evening routine
Get tips from users
Optune Gio Buddy Program
Schedule a chat

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.

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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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US-OPG-00063 v2.0 March 2024