If metformin really slowed aging, you would expect it to change the one outcome that matters most: who dies. Somebody finally tested that in older people without diabetes, and the result was a flop.
Metformin has been in pharmacies since the 1950s and is the most-cited candidate anti-aging drug on the internet.
The case for it is not nothing. In the 1998 UKPDS trial, overweight people with diabetes on metformin had 36% fewer deaths over about 10 years than people managed on diet alone.
@NirBarzilaiMD's TAME trial has aimed to test it properly in more than 3,000 healthy adults aged 65 to 79 for years, and is still raising the money to launch.
Met-HeFT, run from Aarhus in Denmark (
@AUHdk), got partway there. It enrolled 940 people with weak hearts, average age 70, with only about 10% carrying a diabetes diagnosis and the rest running high blood sugar or obesity, then gave them metformin or placebo and followed them for 3.7 years.
Death, worsening heart failure, heart attack or stroke hit 25.1% on metformin and 23.4% on placebo.
Metformin also failed to cut new diabetes, and it caused no harm.
So the takeaway is simple: in a real-world test outside diabetes, metformin did not deliver a longevity win.
One disease group, one country, and a heart endpoint rather than an aging one. The bigger test outside diabetes is the VA's IMPACT trial in 7,410 people with prediabetes and artery disease, reporting around 2029.