Controlling chronic pain isn’t easy. Drugs don’t always provide relief and many have dangerous side effects. Quell is a device that might help people with arthritis, back pain, diabetic neuropathy, fibromyalgia, and other conditions without drugs by sending electrical signals to your brain through your nerves to trigger the brain to release endorphins and other natural painkillers, the company claims.

The stimulation is delivered through a thin, lightweight band equipped with an electrode that you wear on your upper calf. The technology is a form of TENS (transcutaneous electrical nerve stimulation), which is usually delivered in blocks of time. Quell is designed to be worn 24 hours a day and the company claims that it “adjusts to your optimal stimulation level for your most effective pain relief.” You’ll probably feel some tingling in your calf, but you can adjust the intensity of the stimulation. The device automatically reduces the power when you’re sleeping.

An app allows you to control the device with your smartphone and also tracks your sleep. Poor sleep is a problem for people with chronic pain, and a lack of sleep often exacerbates pain.

Quell recently became available without a prescription. The starter kit costs about $250 and comes with two electrodes, enough for a month’s use. After that, you’ll spend $30 a month to replace the electrodes. The device isn’t covered by insurance, but is reimbursable through a flexible spending account.

The company says that Quell can deliver pain relief in as little as 15 minutes, but for many people, it could take several days of use for the device to help. A company spokesperson said that many users report noticing an improvement in sleep before they see an improvement in pain levels. And TENS doesn’t work for everyone. Quell will refund your money within 60 days if you try it and find it doesn't help you.