Metformin

Plain-language summary

A long-established oral medication FDA-approved for type 2 diabetes. It is studied off-label for aging-related outcomes but is not FDA-approved for longevity.

Regulatory status

Evidence snapshot

Limited. Supported mainly by small studies, early-phase trials, or indirect evidence. Conclusions are tentative.

How it works

Lowers blood glucose mainly by reducing hepatic glucose production and improving insulin sensitivity; proposed longevity effects involve AMPK activation and metabolic and cellular stress pathways, which remain under study.

Approved uses and researched uses

Researched uses are studied but not FDA-approved and may be off-label. This is not a recommendation to use them.

Known risks and uncertainties

Common effects are GI upset (diarrhea, nausea) and it can lower vitamin B12 over time. A rare but serious risk is lactic acidosis, especially with significant kidney impairment. It generally does not cause hypoglycemia on its own.

Cautions and contraindications

Contraindicated in significant renal impairment and in metabolic acidosis; caution with conditions predisposing to lactic acidosis, and it is typically held around iodinated contrast imaging.

Consumer considerations

• FDA approval is for diabetes; longevity use is off-label and unproven in healthy people.
• The TAME trial aims to test aging-related outcomes but results are not established practice.
• Long-term use can lower vitamin B12, which may warrant monitoring.
• Kidney function determines whether it is safe to use.
• It is inexpensive and has a long safety record in diabetes.

Questions to ask a licensed clinician

• What is the evidence for taking this if I do not have diabetes?
• How is my kidney function, and does it allow safe use?
• Should my vitamin B12 be monitored?
• What GI side effects should I expect and how are they minimized?
• Do the potential benefits outweigh unknowns for my age and health profile?

Sources