Biohacking Kompakt

Treatment & Procedure

CGM – continuous glucose monitoring

Biohacking

For the advertised target group, metabolically healthy non-diabetics, this research found no randomized trial demonstrating a health benefit of continuous glucose monitoring. This is the central finding of this page.

What a CGM does and does not do

A CGM is a sensor on the arm that records the glucose curve around the clock. It makes visible how individual meals act. This measuring capability is undisputed; what is disputed is what it means for people without diabetes and without prediabetes.

There is no CGM definition of normoglycemia, and CGM values are not validated for diagnosing diabetes. This means the reference against which a user could evaluate their curve at all is missing.

Why the negative finding is the main message here

The existing studies in healthy people are cross-sectional and association analyses with surrogate markers such as HbA1c, not with disease courses. They can show that glucose patterns are related to laboratory values, but not that wearing a sensor makes anyone healthier.

Intervention studies in people without diabetes are small and short. A meta-analysis of 23 studies with 1,074 participants without diabetes, 7 of them randomized, found a benefit for blood glucose only in prediabetes, none in metabolically healthy people. Blood glucose values were measured, not disease courses. Two individual studies concern people at risk: 41 people with prediabetes and 48 people with elevated cardiovascular risk.

What is well supported

  • The device is cleared by the authorities, explicitly also for people without diabetes. On March 5, 2024, the FDA cleared the Dexcom Stelo as the first over-the-counter CGM for adults aged 18 and over not using insulin; people with problematic hypoglycemia are excluded. The clearance concerns the measuring device and its distribution, not a health benefit.
  • The measured value is related to established metabolic parameters. Bermingham 2026 analyzed data from 3,634 people without diabetes and without prediabetes in PREDICT 1–3 (age 46 years, SD 12; BMI 27, SD 6). More time in the range of 3.9–5.6 mmol/l went along with lower HbA1c and lower OGTT glucose; for the predicted 10-year ASCVD risk, the AUC was 0.75. The analyses were exploratory and not predefined.
  • In prediabetes, there is a first intervention finding. A pilot study with 41 participants on real-time CGM with training found HbA1c differences after one year (p=0.007) and after two years (p=0.033). This concerns people at risk, not metabolically healthy people, and the sample size does not support a general statement.

What the studies show

Large cohort, but without a defined endpoint

Bermingham 2026 analyzed data from 3,634 people without diabetes and without prediabetes in PREDICT 1–3, average age 46 years, 83 % women. The analyses were expressly exploratory and not predefined; there was no primary endpoint. More time in the range of 3.9–5.6 mmol/l went along with lower HbA1c. The authors’ conclusion calls for long-term endpoints in order to show a benefit at all.

Review: no solid basis

Liarakos 2025 concludes that there is no strong evidence for broad CGM use in people at risk of diabetes. In addition, the paper notes that CGM values are not validated for diagnosing diabetes and that no CGM definition of normoglycemia exists.

What the scientific literature does not support

In a scoping review, Avner and Robbins 2025 screened 59 sources, 11 of them medical papers and 48 from the gray literature. The gray literature claims additional effects on cancer, mood, energy and sleep. The scientific literature does not support these claims.

Intervention data: benefit only in prediabetes

A 2026 meta-analysis of 23 studies with 1,074 participants without diabetes, 7 of them randomized, found a benefit for blood glucose only in prediabetes; in metabolically healthy people there was no notable benefit. Blood glucose values were measured, not disease courses. Two individual studies concern people at risk: a pilot study with 41 people with prediabetes on real-time CGM with training, with HbA1c differences after one year (p=0.007) and two years (p=0.033), and a randomized study with 48 people with elevated cardiovascular risk on lifestyle scores, whose abstract reports no hard figures.

What the measurement does not show

  • A health benefit in metabolically healthy people. This research found no randomized controlled trial showing a health benefit of glucose monitoring for non-diabetics without prediabetes. Hard endpoints were not studied anywhere.
  • The interpretation of individual curve peaks. There is no CGM definition of normoglycemia, and the values are not validated for diagnosing diabetes. Individual peaks are normal and, on their own, allow no assessment.
  • Effects on cancer, mood, energy or sleep. These promises come from the gray literature of the provider and user scene and are not supported by the scientific literature.
  • The yardstick is missing. For people without diabetes, there is no CGM definition of normoglycemia, and CGM values are not validated for diagnosing diabetes. What a curve flags as a “peak” is therefore based on a threshold that was never set for this group.

Status, approval and legal

The US agency FDA cleared the Dexcom Stelo on March 5, 2024 as the first over-the-counter CGM for adults aged 18 and over not using insulin, expressly including people without diabetes. People with problematic hypoglycemia are excluded.

This clearance is a market authorization and not proof of benefit. It means that the device may be sold, not that its use in healthy people brings a health advantage.

Safety

The evidence reviewed contains no data on physical risks of the sensors. The documented problem is interpretation: for non-diabetics, a CGM is a measuring device without a validated normal range, not a diagnostic device. Anyone who derives dietary decisions from overestimated values may be correcting something that was not abnormal at all.

BK-Score Studied – no benefit shown

Human evidence4
Mechanism5
Safety data6
Hype gap3
Track record of use8

For metabolically healthy people – the advertised target group – the benefit has not been shown: the meta-analysis of 23 studies with 1,074 non-diabetics found the glycemic benefit only in prediabetes, none in people with normoglycemia. On top of that, a measurement problem: a randomized crossover study by the University of Bath with 15 healthy people (Am J Clin Nutr 2025) showed that the sensor systematically overestimated: time above 7.8 mmol/l by about four times uncorrected, and still by about twice after adjusting for baseline values. Hard endpoints were not studied anywhere.

The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless. “Track record of use 9” means used long and widely – that is not proof of efficacy.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)

Frequently asked questions about CGM – continuous glucose monitoring

Does a CGM do anything for non-diabetics?

A health benefit has not been shown. This research found no randomized controlled trial demonstrating a health benefit of glucose monitoring in metabolically healthy non-diabetics. Hard endpoints such as cases of disease or mortality were not studied in any of the papers found. The existing data on healthy people are association analyses with laboratory values.

What does the largest study say about CGM in healthy people?

An analysis of 3,634 people without diabetes and without prediabetes found that more time in the range of 3.9 to 5.6 millimoles per liter went along with lower HbA1c. The analyses were expressly exploratory and not predefined. The authors consider long-term endpoints necessary to show a benefit at all.

Is an over-the-counter CGM proof of benefit?

No. In March 2024, the US agency FDA cleared the first over-the-counter CGM for adults not using insulin, including people without diabetes. A market authorization means that a device may be sold. It is not evidence that its use in healthy people does anything for health.

Do the sensors measure accurately in healthy people?

A randomized crossover study by the University of Bath with 15 healthy people (Hutchins 2025) showed that the sensors systematically overestimate in metabolically healthy people. Uncorrected, they reported the time above 7.8 millimoles per liter about four times too high, and still about twice too high after adjusting for baseline values. This makes glucose spikes visible that may not actually exist at that level.

Can a CGM detect diabetes?

No. CGM values are not validated for diagnosing diabetes, and there is no CGM definition of normoglycemia. For non-diabetics, the sensor is a measuring device without a validated normal range. A diagnosis is made exclusively by a medical examination using the procedures intended for it. Abnormal values are a reason for further evaluation, not a finding.

Does a CGM help against cravings or with energy?

Such additional effects, including claims about mood, sleep and cancer, are found mainly in the gray literature of the provider and user scene. A scoping review screened 59 sources, 11 of them medical papers and 48 from the gray literature, and noted that the scientific literature does not support these claims.

The podcast episode (in German)

Episode 79

CGM: the blood sugar sensor in the fact check

The podcast by Paul Höser (Episode 79) · with Paul & Paula. How the sensor measures without pricking, what it brings – and where the hype overtakes the data. Information only, no usage recommendation.

Listen on Spotify

Related

Sources

Open in the database – with search, filters and comparison (German app)

Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-10-04.