Did the active-6 trial show that Metformin prevents long COVID when taken during a COVID infection

The short version: the ACTIV-6 trial has not been shown to prevent long COVID with metformin, and the evidence you retrieved does not answer this question.

The evidence you provided contains no results from the ACTIV-6 trial. It includes a 2025 scoping review that mentions a "2023 preventive study suggesting reduced PASC incidence when used around acute infection" [5], but that is a summary of a different study, not the ACTIV-6 trial itself. The review explicitly says there is "insufficient evidence for efficacy in established PASC" and that "trials focused on PASC patients" are needed [5]. The rest of the evidence covers metformin's effects on diabetes, heart disease, other viruses, and animal models — none of it tests whether metformin taken during a COVID infection prevents long COVID in humans.

The scoping review's mention of a single 2023 study is not enough to conclude anything. One study, even if positive, does not establish a treatment. The review itself calls the evidence "insufficient" [5]. Without the actual ACTIV-6 results, or any other human trial data in your records, there is no basis to say metformin prevents long COVID.

My call: the evidence you retrieved does not show that metformin prevents long COVID when taken during a COVID infection. Confidence: not clear — the relevant trial data is absent from these records.