Does metformin cause water retention?

Question

Does metformin cause water retention?

Answer 1

At normal doses, metformin has been known to cause asthenia (weakness of uncertain mechanism), diarrhea, flatulence, nausea/vomiting, other gastrointestinal complaints, low vitamin B12 levels, metallic taste and rash.  

More serious reactions include lactic acidosis (the buildup of lactic acid, a normal byproduct of metabolism, in the blood, usually in patients with underlying kidney disease or severe dehydration), and anemia.

It is not known to cause significant fluid retention.  However, medications can cause atypical reactions in some patients.

I would guess that any fluid retention is related to another condition or medication.