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Metformin

Last scientific update: jun 2026

Metformin is the most used medicine for type 2 diabetes. It lowers blood sugar and is also being studied as a possible anti-aging agent.

Metformin at a glance

WorksYes, against high blood sugarStrong
LifespanUncertain in healthy peoplePreliminary
SafeYes, well establishedStrong
UseBy prescription, daily pill

Metformin is safe and effective in diabetes; the idea that it extends life in healthy people is still unproven.

31 studies4 answersupdated jun 2026
Evidence per claim
Effect on lifespan in healthy people is uncertain
View evidence →
Preliminary
Improves blood sugar in insulin resistance
View evidence →
Moderate
Berberine is called the natural metformin
View evidence →
Moderate
Studied via mechanisms such as autophagy
View evidence →
Preliminary
Practical use

For whom

People with type 2 diabetes or prediabetes, by prescription.

Not for whom

Not proven useful for healthy people purely against aging.

Usual dose

Daily pill at an increasing dose, always by prescription.

Key caveats

Main side effect is gut upset; long-term use can lower vitamin B12 absorption.

What we know, and don't

Known

Safe and effective in diabetes
Lowers blood sugar reliably
Well studied over decades

Not yet

Whether it extends life in healthy people
The best dose for anti-aging
Whether it blunts training effects
Common misconceptions
"Metformin is an anti-aging pill for everyone."
Not shown. In healthy people that is not yet proven.Strong evidence
"It is dangerous for the liver."
False. With normal kidney and liver function it is safe.Moderate evidence
How Metformin connects
Conditions
Data sources

Wikidata Q19484 · MeSH D008687 · DrugBank DB00331

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