Well - my hair fell out when I was taking Metformin for just a few weeks - but it hasn't grown back a year after I stopped taking it. As no record was made on my file of all the other more dreadful side effects I got with the tablets, it could be just coincidence, or it could be cause and effect but as 'Metformin is a safe drug' is repeated so frequently by HCPs, it might be true, or it might not - no one wants to find out, it seems.