Best Safety

Side effects Cefaly Medications
Occurence 4,3 % 50 %
Intensity Mild Severe

More than 200,000 Cefaly devices in use. Data since 2008.

Side effects

The side effects of Cefaly

  • Observed in 4.3% of patients
  • Mild and completely reversible
  • Most common: intolerance to the feeling of Cefaly on the forehead
  • Most severe: allergic skin reaction to the electrode

The most common side effects

  • Intolerance to the feeling of Cefaly on the forehead: 1.25%
  • Sensation of fatigue during and after the session: 0.65%
  • Headache after one session: 0.52%
  • Irritation of the skin on the forehead: 0.22%

Electromagnetic features

The magnetic field right next to the Cefaly is below 0,2µT (i.e. 2mG). This value is negligible compared to the field generated by an electric shaver (typically between 15 and 1500µT when measured at 3cm) or by an hair dryer (typically between 6 and 2000µT).

Long-term data

Neurostimulation has been used for more than 20 years with devices that are implanted in the head and which work constantly for several years. The only problems encountered with implantable neurostimulators relate to the surgical procedure involved to implant them, and never to the neurostimulation technique itself. This is why this technique is regarded as exceptionally safe. Cefaly's great breakthrough is to allow this technique of neurostimulation to be used in an external and gentle manner.