Technology, injections & supplies

The 'iLet' closed loop that skips carb counting

The Beta Bionics iLet, which needs no carb counting, is fully compatible with the new Dexcom G7 15 Day sensor from its December 2025 US launch.

Written by Updated 5 December 2025 4 min read
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The 60-second answer

Most insulin pumps that run a closed loop still expect you to count the carbohydrate in your meals so the system can size a mealtime dose. A US pump called the iLet is built around a different idea: instead of counting carbs, you tell it roughly how big the meal is and it works the rest out itself. The recent news is that it now pairs with Dexcom’s new longer-life sensor. It is not sold in the UK, so this is background rather than a choice in front of you, but it is a good illustration of how differently these systems can be designed.

  • A closed loop is a pump and glucose sensor that work together to adjust your background insulin automatically, sometimes called an artificial pancreas.
  • Carb counting means working out the grams of carbohydrate in a meal, which is normally how the size of a mealtime dose is decided.
  • The iLet swaps exact counting for a simple meal announcement: you signal roughly small, medium or large and it takes it from there.
  • It is a US system and is not available in the UK, so nothing about your own pump or routine changes.
  • On UK systems, carb counting is still part of how mealtimes work, and needing to do it is normal, not a step backwards.
What is new

A loop set up from your weight, not a page of settings

The iLet, made by Beta Bionics, is designed to need less numeric input than a typical pump. Rather than being programmed with a full set of personal dose settings, it starts from your body weight and adjusts from your own glucose over the following days. At meals, you make an announcement about the size of what you are eating instead of entering a carbohydrate figure. The news itself is small: from its December 2025 launch, the iLet is fully compatible with the Dexcom G7 15 Day sensor, the longer-wear version Dexcom released in the US.

Why it matters here

Less daily input, and the trade that comes with it

The appeal is easy to see. Carb counting is one of the more tiring parts of type 1, and a system that asks for less of it takes a daily mental load off. Meal announcements are also simpler to teach, which can matter for people who find counting difficult or stressful. It is worth being level-headed too. Handing more of the decision to the system means trusting it with meals it cannot see in detail, and a rough announcement is a rougher instruction than an accurate count, so different designs land differently for different people.

For UK readers the practical bottom line is short. The iLet is not available here, so this is not a system to ask to switch to. The closed loops offered on the NHS still use carb counting, and knowing how to count remains a useful skill whatever you end up using. If counting is the part you find hardest, that is genuinely worth raising with your team, because there is often support and there are ways to make it simpler.

What to notice

Worth knowing

The iLet is a US system and is not available in the UK, so this is background on how designs differ, not a choice in front of you.
UK closed loop systems still use carb counting, and being able to count carbohydrate is a useful skill on any of them.
Needing to count carbs is not a sign you are behind: it is simply how the systems available here are set up to work.
If carb counting is the part you find hardest or most draining, your diabetes team can often help make it more manageable.
What to ask your team

Questions that make an appointment useful

"Which closed loop systems does our service offer, and how much day-to-day input do they each need?"
"I find carb counting difficult: is there support or a simpler approach that could help me?"
"How accurate does my carb counting really need to be on the system I use?"
"Are any lower-input systems like this expected to reach the UK in a way that would matter for me?"
Sources