Timing Protocol
When to Take Metformin — Expert Timing Protocols
Expert-analyzed timing recommendations for metformin based on what 5 longevity researchers say about when, how, and what to take it with.
Quick Timing Guide
Typically taken with meals to reduce GI side effects. Extended-release formulations are usually taken once daily with dinner. Attia notes that timing relative to exercise matters — metformin may blunt exercise-induced mitochondrial adaptations.
Moderate Consensus
on Metformin overall
Full Protocol
Timing
Typically taken with meals to reduce GI side effects. Extended-release formulations are usually taken once daily with dinner. Attia notes that timing relative to exercise matters — metformin may blunt exercise-induced mitochondrial adaptations.
Dosage
500-2000mg per day for type 2 diabetes (standard clinical dosing). For off-label longevity use, lower doses (500-1000mg) are sometimes discussed, though no expert consensus exists on longevity-specific dosing. The TAME trial uses 1500mg/day.
Form
Metformin is a prescription drug (brand name Glucophage), not a supplement. Extended-release (ER) formulations are generally preferred to reduce GI side effects. It is a biguanide-class medication.
Notes
Metformin is a prescription medication, not an over-the-counter supplement. Attia's evolution on metformin is instructive: he moved from cautious interest to active skepticism for healthy individuals, concluding that the mitochondrial inhibition that helps diabetics may harm people who are already metabolically healthy and exercising. Most experts agree it remains an excellent first-line diabetes drug but question its value as a longevity tool for healthy people.
Expert Positions
What Each Expert Says About Timing
Huberman covers metformin across 5 videos, ranging from blood glucose regulation to a dedicated Journal Club episode. In his Journal Club with Attia, they critically examine metformin studies, particularly the 2014 Banister study and a newer Danish twin study that cast doubt on metformin's survival advantage. In his longevity supplements AMA, Huberman explicitly states he avoids metformin, berberine, and rapamycin for longevity. He also discusses metformin as a glucose-lowering prescription drug in his hunger and satiety episodes, noting its potency but warning about hypoglycemia risks. A guest episode with David Sinclair touches on metformin as part of Sinclair's personal longevity protocol.
Unlock the Full Picture
Go beyond the consensus — see exactly what each expert says about metformin.
- Per-expert timing protocols & reasoning
- Interaction warnings & disagreements
- Video citations with timestamps