CGMs in Diabetes Care

Where CGMs started

Continuous glucose monitors were built for people with diabetes, and that is where the strongest evidence is. This page summarizes what research and guidelines say. It is general information, not advice about your treatment. Decisions about medicine, devices and targets belong with your diabetes care team.

Type 1 diabetes

A 2025 systematic review and meta-analysis of 27 studies with 2,975 adults with type 1 diabetes found CGM reduced HbA1c (a lab measure of average glucose) compared with standard monitoring, and increased time in range by 7.9%. [1] [2] UK guidance (NICE, updated 2022) tells clinicians to offer adults with type 1 diabetes a choice of real-time or intermittently scanned CGM, and says CGM should be provided by a team with expertise in its use. [3] [4] NICE adds that fingerstick checks are still needed as a back-up. [5] Label: established for improving glucose control measures in type 1 diabetes. A meta-analysis of 64 randomized trials also concluded that in type 1 and type 2 diabetes real-time CGM decreased HbA1c and increased time in target range. [6] [7]

Type 2 diabetes

Results are more modest and depend on treatment.

• Overall: a 2024 meta-analysis of 12 trials in adults with type 2 diabetes found CGM was associated with better glucose control than fingersticks, but all studies were open label (people knew which group they were in), and data on severe low blood sugar and long-term complications were scarce. [8] [9] [10]
• Not on insulin: a meta-analysis of six trials in 407 people with type 2 diabetes not using insulin also reported improved glucose control. [11]
• Size of the effect: a 2026 review described a modest but consistent HbA1c reduction of approximately 0.3% compared with fingersticks or usual care. [12] The same review concluded CGM should be used in response to a specific patient problem rather than as a default. [13]
• Side effects: one meta-analysis found CGM and scanned CGM were associated with an increased risk of adverse events. [14] Skin irritation from the sticky patch is one example. [15]
• Guidelines: NICE's type 2 diabetes guideline (updated February 2026) lists the effectiveness and cost effectiveness of CGM in adults with type 2 diabetes as a research question. [16]

Label: promising but limited for type 2 diabetes.

Reading the numbers

International consensus recommendations from 2019 describe how CGM data should be used and reported for people with diabetes. [17] Those targets are for diabetes care. They are not normal ranges for everyone, and this page does not give personal targets. See Consumer Data vs Clinical Measurements.

What this does not tell you

All of this evidence is from people with diabetes. It does not show that wearing a CGM helps people who do not have diabetes; see CGMs in People Without Diabetes: What Evidence Exists.