For those who suffer from migraines, yet want to cut back on painkillers, researchers have been working on developing small head devices that may one day treat migraines with electric pulses. The latest device to move forward in testing is StimRelieve Halo Migraine System, a tiny implant inserted in the forehead.

Last year, the company that designed the product — StimRelieve LLC — received FDA Investigational Device Exemption (IDE) approval to begin a clinical trial in which over 140 people are currently taking part. Half of the participants will receive an implant that is working, and the other half will receive an implant without batteries (in order to account for the placebo effect). The StimRelieve Halo is one of the smallest devices to be created for this purpose, and can be implanted with a gauge needle, eliminating the need for surgery or anything invasive.

The StimRelieve Halo works by sending electric pulses to stimulate nerves which, theoretically, alleviate pain. It’s a type of occipital and supraorbital nerve stimulation, using wireless neuromodulation technology. In addition to a small implant in the forehead, the device involves an external transmitter on the ear, which sends energy to the implant.

“Chronic migraine headache pain is a crippling condition, disabling millions of Americans every year,” said Dr. Konstantin Slavin, professor of neurosurgery at the University of Illinois, in a press release. “If determined safe and effective, StimRelieve’s wireless neuromodulation device offers a promising option for alleviating and controlling this type of condition so that those living with this pain can better function and go on with their lives.”

StimRelieve Halo isn’t the first implanted device that’s been a treatment option for migraines. In 2014, the FDA approved Cefaly — a crown-like device that is attached to the forehead and treats pain through electric pulses as well. In experimental trials to test Cefaly, researchers found that 38 percent of participants experienced a 50 percent decrease in migraines, compared to only 12 percent in the placebo group. While it appears that these devices may not help everyone, there was enough of a “therapeutic gain” to approve it for use. It’s likely that StimRelieve Halo will have a similar level of efficacy — perhaps working for a chunk of the population, but not for others.

Because of the limited amount of data on these devices, the American Migraine Foundation notes that while clinical trials have shown them to be safe, there is no official certainty on whether they can truly be used as a substitute for medication in migraine treatment. “[I]t is premature to make any definitive statements about the long-term and sustained effectiveness of the device,” the American Migraine Foundation notes on its website. “ Since there are relatively few side effects or significant potential consequences it may be a beneficial tool to have available for patients who are either hesitant to try other preventive treatments or patients who for other health reasons cannot use other preventive treatments. ”