Timing your metformin: before meals may boost carb blocking

NCT ID NCT04018105

Completed Knowledge-focused Sponsor: University Hospital, Lille Source: ClinicalTrials.gov ↗

First seen Jun 26, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This pilot study tested whether taking metformin 30 or 60 minutes before a meal affects carbohydrate absorption in people with obesity and prediabetes or type 2 diabetes. One participant completed three oral glucose tolerance tests—one without metformin, one with metformin taken 30 minutes before, and one taken 60 minutes before. Researchers measured blood sugar, insulin, and a sugar marker called D-xylose to see how timing impacts absorption and digestive side effects.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance: metformin
What this could lead to: If it works, this could help doctors recommend the best time to take metformin for better blood sugar control.
What could go wrong: This is a very small pilot study with only one participant, so results may not apply to others. It only looks at short-term effects, not long-term outcomes.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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Conditions

The condition(s) this trial relates to.

glucose intolerance Obesity prediabetes syndrome type 2 diabetes mellitus

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

IMPAIRED GLUCOSE TOLERANCE TYPE2 DIABETES

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