Do you have a link for that? I've heard of plenty of metformin side effects (from gastric to B12 deficiency) but weight gain is not familiar to me....
My GP has offered to give it to me if I wish...
https://bmcendocrdisord.biomedcentral.com/articles/10.1186/s12902-017-0228-9
This is a quote from the study. It doesn’t seem like it would normally be prescribed for a Type 1 with good control.
“Metformin is an oral anti-hyperglycemic agent and commonly used in the treatment of type 2 diabetes. It increases both hepatic and peripheral insulin sensitivity in the liver by inhibiting basal hepatic glucose production, as well as in skeletal muscles and adipocytes, by increasing glucose uptake [
4,
14,
15]. Thus, it enhances insulin action and improves glycemic control. Metformin leads to reduce insulin dose requirement as well as weight gain because it increases insulin sensitivity. In this respect, compared with insulin monotherapy, the addition of metformin to insulin therapy improves metabolic control and decreases complications in type 2 diabetes [
16]. Metformin has been shown to increase insulin sensitivity [
17] and reduce metabolic syndrome incidence in people with prediabetes [
18]. The addition of metformin to insulin therapy in type 1 DM is still under debate. Until now, a limited number of studies have investigated the addition of metformin to insulin therapy in type 1 diabetics [
4,
19,
20,
21,
22]. Metformin as an adjunctive therapy is not formally recommended in type 1 diabetes unlike in type 2 diabetes [
23].”
).