Loop is an open-source, community-built automated insulin delivery (AID) system designed for iPhone and Apple Watch. It allows people more control over their diabetes with customizable options that offer more flexibility and control over treatment.

Loop isn’t backed by a traditional medical device company and it is NOT FDA-cleared. Instead, it was created by a passionate group of developers, engineers, and people with diabetes as part of the #WeAreNotWaiting movement—frustrated by the slow pace of commercial innovation. You can learn more about Loop and its history in the below video I made while working at CNET.

Once set up, Loop’s algorithm predicts blood glucose levels and automatically adjusts basal insulin and delivers microboluses to help maintain a user’s target range. Settings like glycemic index food log options and custom overrides for events like exercise or illness make Loop one of the most customizable systems available. I go into greater detail on standout Loop features in my All Access Starter Guide for Loop.

There’s no customer service team or tech support hotline. Instead, users rely on the Looped Facebook group, Reddit, and the Loop and Learn Youtube channel for troubleshooting and guidance.

Despite its DIY nature, Loop users often report excellent time-in-range results and a renewed sense of autonomy in their diabetes management—especially among parents of children with type 1 diabetes and tech-savvy adults seeking more control.

That said, because the app is unregulated and self-built, users must assume full responsibility for safety and accuracy. It’s a tool that rewards those willing to learn, tinker, and take ownership of their diabetes care. Still, the Loop community has helped shape the future of diabetes tech—pushing the industry toward greater openness, interoperability, and user-led design.

In order to use Loop, users must follow instructions on Loop Docs and build the app themeselves—then pair it with compatible hardware, such as:

If you’re curious about what it’s like to use DIY Loop and controlling it with an iPhone and Apple Watch, I’ve got you covered. In my video at the top of this page, I break down the pros, cons, setup process, and what it’s been like using Loop in the real world for over three years.

Disclaimer: Diabetech content is not medical advice—it’s for educational purposes only. DIY Loop is experimental and not approved by the FDA or regulatory authorities at the time of this video. You take full responsibility for building and using DIY Loop and you do so at your own risk. Results will vary. Always consult with a physician before making changes to your healthcare.