Timing Protocol

When to Take Metformin

What researchers say about when, how and with what to take metformin, and how strong the evidence is.

The verdict on Metformin overall

Leaning against

Metformin slows aging in people without diabetes.

5 sources: 1 partly, 2 neutral, 2 negative

5 sources: 1 partly, 2 neutral, 2 negative

Based on what researchers say in publicly available videos, not medical advice. Always consult your healthcare provider before starting, stopping, or changing any supplement.

Short answer

Usually taken with meals to reduce gut side effects; extended-release forms are usually taken once daily with dinner. Timing around exercise matters, because metformin may blunt exercise-driven mitochondrial gains (Peter Attia).

Full Protocol

Timing
Usually taken with meals to reduce gut side effects; extended-release forms are usually taken once daily with dinner. Timing around exercise matters, because metformin may blunt exercise-driven mitochondrial gains (Peter Attia).
Dosage
500-2000mg per day for type 2 diabetes (standard clinical dosing). Lower doses (500-1000mg) are sometimes discussed for off-label longevity use, with no agreed longevity dose. The TAME trial uses 1500mg/day.
Form
Metformin is a prescription drug (brand name Glucophage), not a supplement. Extended-release (ER) forms are generally preferred to reduce gut side effects. It is a biguanide.
Notes
Metformin is a prescription drug, not an over-the-counter supplement. The mitochondrial inhibition that helps people with diabetes may harm people who are already metabolically healthy and exercising (Peter Attia). It remains an excellent first-line diabetes drug; its value as a longevity tool for healthy people is in question.

What the evidence says about timing

One verdict, worked out from every counted mention. One dot is one source: a researcher or a study. Tap a dot to see its receipt.

positive partly neutral negative Each researcher and each study counts once per claim, however often they come up.

Not enough evidence

Taking metformin with meals reduces stomach side effects.

No counted mention yet.

Where the sources disagree

Built from every credited researcher and cited study on each claim.

Leaning against

Metformin slows aging in people without diabetes.

Partly 1 source
Against it 2 sources

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Full Metformin Report

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Metformin verdict