i'm on metformin twice a day....haven't noticed any tiredness/weakness but this is the second time i've tried this med. the initial try left me w/reactions and i was taken off of it...i noticed that i instantly had joint pain in my elbows and wrists first...i had to roll over on my tummy and slide myself off the bed, i couldn't handle the weight on my arms! then i was sitting at computer later that day nad noticed i had immense pain in my ankles and knees and only when i tried to stand and could barely, did i realize that my hips were suddenly affected. i could barely move much less walk w/o in pain and near tears.

my dr. switched my meds to actos and found they didn't work as well and was leaning toward injections when i said....reactions or not...i want to try the metformin once again....this time...i've not had any reactions though one day i was particularly achy in the joints...i've been fine on it!? some weird coincidence, an allergic reaction....i'm not sure but i would try anything again before injections!!

have you tried getting vitamins, minerals, watching your intake of certain things like caffeine, etc that may affect their usefulness? i'd talk w/my doc immediately....maybe actos may work for you? good luck!