The studies I've seen indicate that metformin can interfere with building muscle (probably due to reduced ROS from exercise).

I suspect that Berberine (which similarly is a very mild mitochondrial poison) does the same, but haven't seen any studies touching on that.

That said, the study linked was done in India - and there are some very specific insulin/glucose related issues with South Asians (that get larger as you get closer to the equator). If you listen to Peter Attia's Drive podcast, he's recorded an interview with Ronesh Sinha that touches on this.

Dr. Sinha's website https://www.culturalhealthsolutions.com likely goes into this in greater depth, but I haven't dug in.

In the interview, they touch on many South Asians being somewhat insulin resistant even in the womb - possibly because it spurs intellectual growth. (something I've added to my "antagonistic pleiotropy" list)

This IMO is an interesting area. Keep ''em coming, please.

Obligatory snark: regarding the photo in the article: if you're getting your neck all tensed up to open a jar, you're almost certainly doing it wrong :-)