WHAT THE HUMAN DATA SAY
Evidence before enthusiasm.
Metformin improves outcomes for established metabolic indications, but evidence that it extends life in healthy, metabolically normal people is not established. Potential exercise adaptations and nutrient effects matter.
This grade reflects clinically meaningful human evidence for the use described here. It is not a score for popularity, mechanism, animal lifespan results or the number of products already being sold.
HOW IT FITS
A practical role—without pretending it is universal.
Use it when a qualified clinician identifies a valid indication and monitoring plan. Do not treat family history or curiosity alone as a prescription.
TRACK WHAT MATTERS
Know whether it is creating value.
A1c, glucose and clinical indication
Kidney function and gastrointestinal tolerance
Vitamin B12 during long-term use when appropriate
SAFETY & BOUNDARIES
What should make you pause.
- Gastrointestinal effects and B12 deficiency are common considerations.
- Kidney, liver, acute illness, hypoxia and contrast-procedure context can change safety.
- Rare lactic acidosis risk requires appropriate prescribing.
BOOK CONNECTIONS
Where this idea enters the longevity conversation.
Book inclusion explains why the idea is culturally important; the evidence grade above determines how strongly The Modern Bio treats the claim.