Recent quotes:

Metformin Should Not Be Used to Treat Prediabetes - PubMed

Since the association between prediabetes and cardiovascular disease is due to the associated nonglycemic risk factors in people with prediabetes, not to the slightly increased glycemia, the only reason to treat with metformin is to delay or prevent the development of diabetes. There are three reasons not to do so. First, approximately two-thirds of people with prediabetes do not develop diabetes, even after many years. Second, approximately one-third of people with prediabetes return to normal glucose regulation. Third, people who meet the glycemic criteria for prediabetes are not at risk for the microvascular complications of diabetes and thus metformin treatment will not affect this important outcome. Why put people who are not at risk for the microvascular complications of diabetes on a drug (possibly for the rest of their lives) that has no immediate advantage except to lower subdiabetes glycemia to even lower levels?

Outpatient treatment of COVID-19 and incidence of post-COVID-19 condition over 10 months (COVID-OUT): a multicentre, randomised, quadruple-blind, parallel-group, phase 3 trial - The Lancet Infectious Diseases

The cumulative incidence of long COVID by day 300 was 6·3% (95% CI 4·2–8·2) in participants who received metformin and 10·4% (7·8–12·9) in those who received identical metformin placebo (hazard ratio [HR] 0·59, 95% CI 0·39–0·89; p=0·012). The metformin beneficial effect was consistent across prespecified subgroups. When metformin was started within 3 days of symptom onset, the HR was 0·37 (95% CI 0·15–0·95).

The brain aged more slowly in monkeys given a cheap diabetes drug

Monkeys that received metformin daily showed slower age-associated brain decline than did those not given the drug. Furthermore, their neuronal activity resembled that of monkeys about six years younger (equivalent to around 18 human years) and the animals had enhanced cognition and preserved liver function.

A break from Covid waves and a breakthrough for preventing Long Covid

But a new randomized, placebo-controlled trial of metformin has yielded exciting results—the first drug to be shown to help prevent Long Covid. Over a thousand people with mild-to-moderate Covid were randomly assigned to 2 weeks of metformin (500 mg pills, 1 on day 1, twice a day for 4 days, then 500 mg in AM and 1000 mg in PM for 9 days) or placebo. There was a 42% reduction of subsequent Long Covid as you can see by the event curve below, which corresponds to an absolute decrease of 4.3%, from 10.6% reduced to 6.3%. Of note, the participants in the trial were fairly representative of the people who most often go on to manifest Long Covid, outpatients with a median age of 45 years and 56% were female. The low risk subgroups of people age <30 years or with a normal BMI were excluded. There were no treatment by subgroup interactions—that is there were overlapping 95% confidence intervals for the direction of benefit for metformin for all subgroups; no clear evidence that metformin worked better or worse for each.

Forget the Blood of Teens. Metformin Promises to Extend Life for a Nickel a Pill | WIRED

He was confident that metformin was good enough for the job. He has maintained this confidence ever since he read a 2014 study that reviewed the fate of 90,400 type 2 diabetics taking either metformin or another medication. The metformin patients in the study not only outlived the diabetics taking the other drug—a not especially surprising result if metformin is a superior treatment—but also outlived the nondiabetics studied as a comparison.