Glucophage is a relatively recent diabetes medicine in the U.S., although it has been available in other countries for over a decade. It is prescribed to people with NIDDM, or “adult onset” diabetes.

Although it lowers blood sugar both right after meals and between meals, it works differently from most other diabetes pills.

It improves the body’s response to insulin and reduces the liver’s output of sugar. It also lowers blood fats somewhat, and it is hoped this will reduce the risk of heart disease.

Glucophage may be used alone or in combination with other diabetes pills.

Side Effects and Interactions

The most common side effects of Glucophage are digestive: loss of appetite, nausea or diarrhea. These may fade with time. Rash, flatulence, and a metallic taste have also been reported.

One rare but serious adverse effect may occur when a person has kidney problems or becomes dehydrated. Lactic acid may build up in the bloodstream and lead to dangerous consequences. Contact your doctor promptly if you feel ill, with muscle aches, trouble breathing, stomach pain and drowsiness. Blood tests will determine if lactic acidosis has developed. This is a medical emergency.

If Glucophage seems to be losing its effectiveness for controlling blood sugar, discuss the situation with your doctor.

Furosemide (Lasix) can increase blood levels of Glucophage, while levels of furosemide may be lower than expected. Nifedipine (Adalat, Procardia) can also boost Glucophage levels modestly, while cimetidine (Tagamet) can raise Glucophage levels substantially.

Other drugs, including Lanoxin (digoxin), quinidine and Zantac (ranitidine), might theoretically increase Glucophage blood levels but no interactions have been reported yet.

Medications such as cortisone or estrogen that tend to raise blood sugar may interfere with the effectiveness of Glucophage. Check with your physician and pharmacist regarding potential interactions of Glucophage with any other drugs or herbs you take.

Special Precautions

People with poor kidney function may need lower doses of Glucophage to avoid a dangerous build-up of the drug. Older people may also need dosage adjustments so that they take the minimum possible dose that controls blood sugar. Periodic monitoring of kidney function is essential.

Glucophage should be stopped temporarily before surgery or any x-ray procedure using iodinated contrast media (“dye”). Ask your doctor for specific instructions.

Taking the Medicine

Glucophage is usually taken with meals, twice a day. It works best in patients following a sensible diet for diabetes. Excessive alcohol intake can increase the potential for a serious reaction and should be avoided by people taking Glucophage.

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  1. jack

    I have been taking this Metformin for about a week now. I’m stopping. Twice a day 500mg. No More. I would rather be in spinal cord pain than feel like this. It’s the same feeling I had on a good day when I was on chemo. This isn’t living. I feel horrible. Legs and arms feel like a hundred pounds each, and the headache won’t go away. I won’t even start with the gastro issue. I’m done. The VA Dr will probably have a fit, but it’s my life. I will get on a bike indoors and lose weight and stick to a strict diet. Alcohol isn’t an issue, I don’t drink at all. This stuff is really obviously terrible for more people that they lead on to. I was told it has been around for ages. Good I hope it helped people. Just won’t be helping this one. I swore I wouldn’t live “feeling like crap” every day ever again. I meant it. I haven’t left the house in 5 days! Good luck to all

  2. sue

    I began taking Metformin 500 mg not for diabetes but for alternative cancer prevention. A few days after starting I got a yeast infection… I thought this was odd as I haven’t had one of those in decades. I treated with over the counter–felt better–on week 2 I got that familiar pain of a urinary tract infection. During week 2 began to to feel my limbs heavy and numb and tingly. I also started having frightening heart palpitations and chest pressure. I almost went to the ER this weekend. I became so frightened with the muscle pain and numbness. PS I am a fit, 48 year old woman who works out regularly.

  3. J.M.F.

    How long does it take for Metformin to leave the system? Taking Metformin 1000 mg Bid.
    Before going into hospital and taking Metformin had bouts of diarrhea. While in hospital was put on insulin and had no diarrhea. On discharge 2 days ago was put back on Metformin and diarrhea resumed. Any suggestions?

    • jenn

      Metformin is eliminated from the body by the kidneys and has a half-life of 6 hours, meaning that roughly 94% of the drug is removed from the body in 24 hours.

  4. donald c

    On 2000 metformin a day at night after dinner.
    I have been on this dose for 3 weeks and the last 4 days have been sitting in rest room with servere gastro. Is this common? please help.

    • Stephanie

      Try limiting carbs and sugars. Also avoid alcohol.

  5. JG

    Does anyone have urine leakage with metformin?

  6. AMT

    Absolutely DID NOT work for me. 500mg dose 1x per day, taken at lunch, completely wiped me out. So exhausted that I could not get through my day at all. I work two jobs, so this was a complete disaster. My arms and legs felt weak, shakey, like rubber; without any strength at all. My mind would not think of things, and tasks like making a grocery list took me much longer because the thoughts wouldn’t work. I felt drugged and drunk. Blood sugars always tested okay. All I wanted to do is sleep.
    It DID bring my blood sugars right where they were supposed to be, but at what price?? I couldn’t keep taking it. Why does a medicine that works so well on my sugars have to make me feel so awful? It isn’t fair.

    • Stephanie

      Take it at bedtime? The first month I was exhausted also.

  7. david

    I would say everyone on med should stop their meds and adjust diet and exercise. I get the same results with or without med, but everyone is different.

  8. MDP

    I am 66….been on Metformin ER for over 1 year…..having terrible cramping and loose watery stools for over 2 weeks now….my numbers are in good range…in fact….I was told I was pre-diabetic and numbers were only 6.8-7.0…….now I am a little below that and they say I am managing it fine now.
    However…since on Metformin ER….nothing but problems…..gastro, tiredness (which they tested my thyroid and I am on 150mcg dosage)…and now these terrible stomach pains and diarrhea….what to do…I want to quit the meds……what to do….anyone!?

  9. S.

    I am a women of 68 years young. Been taking Met for 10 months.I was pre diabetic but Dr. put me on it anyway. I was swollen in the legs and ankles. Weight loss was 20 lbs. and then a stand still. No energy and and all I wanted to do was Sleep and be left alone. This is my problem and reason I quit the Metformin and will do this on my own.
    After going to the Dr. 2 weeks ago for blood work, (all results were good) I woke up one morning having a period. Called the pharmacist and he called it Renewed ovulation from Metformin. I feared cancer but was reassured that if it were, it would have shown up in my blood work. And if it were Cyst, I would have had pain. Anyone else that can tell me about this ? By the way I check my blood 3 to 4 times daily and I stay in the low 100’s range.

  10. fj

    I have been taking metformin 500mg 2 times a day every since late last year when I found out I was a diabetic. It as been a rocky road while being on this medicine. I have lost weight but I wish I didn’t have to take this medicine. I have experienced drowsiness, heart palpitations, stomach pains and weakness. I know we are supposed to lose weight but I have to eat a certain amount of food so that the medicine won’t make me sick. Today I ate breakfast and took my first dose, minutes later I started feeling woozy and lightheaded. I was having stomach pains on both at sides like someone had pliers squeezing and twisting them on my stomach. I thought I ate enough food so I’m I having this problem? I’m afraid to take my next dose of metformin. Please help asap?!!!!!

  11. AH

    My 93 year old mother has been on Metformin 500mg bid for some time plus takes Glybizide. She recently started having lightheadedness and stomach pains. Should she maybe decrease the Metformin to one a day because she also has no appetite?

  12. MFV

    Well, after reading this and doing physical therapy for weeks for knee and joint pain which is not getting better. Actually, now add shoulder pain and tired all the time. Schedule a new sleep study thinking that was the problem. Thinking all the stomach, digestive problems were gallstones issues.
    I done with metformin. Big Pharma wants you to believe these are isolated cases when in fact they are not. Also, my blood pressure was high end of normal now its cross the line and the doctor wants to add lisinopril. Enough, bs from big pharma, “there is a one to one correlation between Metformin causing high blood pressure, joint pain, depression, mood swings, anxiety, swollen feet and legs and heart racing. Just to name a few. The metformin and lisinopril are such wonderful drugs they are now handing them out to the public for free. No thanks! I am tired of being test subjects for Big Pharma.

  13. G M

    *****Please call your doctor RIGHT NOW.*****
    Suicidal thoughts should be taken VERY seriously by you and your health-care providers. Also tell your family what’s going on, so they can better help you. Don’t fear psychological counseling; seeing a therapist was one of the best decisions of my life.
    I think your physician is the best resource regarding the water retention and bloating. Since getting off Metf., I’ve noticed that I easily react to high amounts of sodium (salt), BUT that can be a symptom of other issues.
    Read labels on food, beverages, and OTC medicines, so you’ll be aware of sneaky hidden sodium. I react to the sodium in Coca-Cola and in docusate-sodium stool softeners.
    Blessings to both of you!

  14. KH

    I’m taking metformin for PCOS. I’ve been taking it for around 3 weeks, as well as provera. I take the provera for the 20-29th of each month (in other words, as of writing this I’ve been off it for a week so I know it’s no longer having an effect on my body). Ever since I started the metformin I am suffering from huge mood swings and horrible depression and anxiety. I have a history of depression and anxiety, but never like this. I am on edge, I have a horrible short fuse, all I want to do is cry… The list goes on.
    I know it is the metformin causing this, however my question is will this go away? If I only have to feel like this for a short time, I think I can handle it, but if it might not go away I can’t do it. It is helping my PCOS, and I want to keep taking it for that reason, but not when every day I’m thinking about different ways to die and flipping out on my family over absolutely nothing.
    As a side note, I also suffered from some stomach upset and vivid dreams/nightmares for about a week after starting the metformin, but they appear to have all gone away now. Just this horrible depression and anxiety are still bothering me.

  15. Laura

    I have been taking Metformin for more then 10 years for PCOS, can Metformin cause bloating? and water retention?
    My stomach is always big and feels hard, I cannot understand, I am eating more fiber,
    thank you

  16. RA

    Please do not blame metformin. I agree side effects are possible, however blame it on the disease i.e. diabetes.
    Without diabetes there would be no need for metformin. (Possible side effects as with every medication).

    • MA

      I’m not even diabetic, I have PCOS, that’s why I take it and I’m still having bad side effects. So YES people can blame the medications!

  17. MAA

    taking 1000mg 2x a day for a month. Urine is dark yellow all day long and smells terrible. BS is down and stable but other side effects are mild diarrhea and numb cold feeling in legs
    Ate pizza for lunch and BS spiked to almost 190 after eating

  18. adv

    I stopped taking it. It took about 3 weeks for the yeast infection to go away completely, but I am not taking it anymore. I will find something else if I have to. I would suggest if you are still having problems, talk to your doctor and see if you can be put on something else..

  19. BH

    I was wondering the exact same thing. I have, rather incredibly, all of the factors you mentioned except I have never been diagnosed with PCOS–tho suddenly I definitely feel I should look into it. I have a massive predisposition towards candida: being prescribed an antibiotic usually results in a vast number of tears and having a lot of trust with a new doctor. I have been on and off with taking the metformin as the gastric discomfort and time spent in the rest room served to make me not only miserable but quite useless as well. I recently started back up and noticed a sudden onset of migraines (though they had gone down for a very long time now–happening more like once a month instead of 2-3 each week) as well as several major thrush symptoms I haven’t seen the severity of in years! I realize this is 2 years later :/ maybe you have some answers to share with me?

  20. adv

    I have just started metformin again for the second time and both times I realized that I have developed a severe yeast infection. I do not know if this could be a side effect or allergy, if anyone knows, please let me know thanks.

  21. L N O

    I have been on metformin for about 4 years but suddenly i started developing joint pains especially at the phalanges. My doctor asked me to stop but without an alternative. My bg has not been under proper control since then.
    Question: Is this a known side effect of metformin?
    Is there an alternative that can effectively replace metformin?
    People’s Pharmacy response: Not a common side effect of metformin.

  22. educateyourself

    while it’s all well and good that this medication works well for some. It is being prescribed for multiple conditions, and sometimes by well meaning docs who really don’t know what the real effects of this medication are. They are unable to answer questions regarding side effects that have been reported, but not documented by big pharma.
    I’ve lived with the after effects of this medication for years after stopping it (have never been diabetic or even remotely insulin resistant). The allergies I’ve developed, the muscle fatigue and constant upset stomach coupled with ibs-like symptoms ARE very real and are important things for people to know before blindly taking the medication. If I had known this could happen I never would have taken the meds in the first place!
    I also have family members who have taken it for diabetes and they had very similar experiences, but once stopping the meds, their symptoms stopped, while mine have continued for years. if in 30 or 40 years I develop a problem with my blood sugars, it will be my motivation to eat right and exercise to control them because I OUTRIGHT REFUSE to ever take this drug again!

  23. W.E.Burnett

    It seems to me, this helpful website is a magnet for complaints. Not too many people saying metaformin works great. The only problem with this, is the demographics are way out of balanced.
    A peruser of these pages may come under the assumption that there are too many negative aspects to this drug, when in fact, they’re visiting a website containing mostly peoples negative reports of side effects.
    These side effects really do exist, and this is the place to air out these experiences. Imagine what it would be like, if no site like this existed? YIKES! Yet this pool of negative side effects, may cause fear or doubt to those who happen to read about this drug, not realizing these pages of reports, make up a small number of millions who have positive experiences, and these far, outweigh most accounts found here! Kind of like a vortex of fear.
    At times this presents fodder for some sneaky ones, to recruit adherents to alternative non-medical therapies to spend their money on. Yes, this drug has side effects, as reported here. But the side effects of diabetes are many and serious. Every hour, worldwide, people by the thousands are suffering the grave results from this disease. Amputations, Blindness, Organ failure, etc. Not too many people are experiencing those side effects from Metformin.
    The gracious hosts of this site, do all they can to alleviate some of the “wilder” side effect questions expressed, while allowing the public freedom to use this site. Thus, please remember even though these reports on this webpage are true and need to be reported and compared, you are not reading about the invisible, vast majority of people with nothing to complain about, concerning this drug!
    -Just an observance and opinion that is relegated to the bottom of a huge pile of comments.
    People’s Pharmacy response: Thank you for the observation that most people who are happy with their medications do not go online to praise them. In our opinion, metformin is one of the best prescription drugs for type 2 diabetes.
    To the extent that people are able to control their blood sugar with diet, supplements, and exercise, we cheer for them. But not everyone is able to achieve complete control in that manner. For them, a medication like metformin can be extremely useful.

    • A.R

      Thank you!

  24. G M

    CORRECTION to my post of Sept. 10, 2012
    GASTROENTEROLOGIST was aware of gastric issues when starting metformin but not aware of issues related to long-term use. Asked endocrinologist to send info on long-term effects to gastroenterologist.

  25. G M

    See my posts of Sept. 2012 and May 2013.

  26. Jp

    I have been on Metformin for about 3 1/2 years now. I am having all kinds of stomach pains, food intolerances, and allergies that I did not before ask well. I have an appt. with a GI doc in a couple weeks, but now I’m thinking it could be the Metformin. I am on it for PCOS.

  27. lm

    That’s what brought me here. Now it’s confirmed. I’d rather have a short sane happy life than a longer one riddled with serious mood swings, leg cramps and diarrhea. Thank you for sharing, my experience with met has been like yours.

  28. Kb

    Did they change your medication? I tried the Met ER and then the regular taking 1/2 250 mg and it keeps interacting with my Armour Thyroid. Went off of the Met and my body started to calm down. I m on Day 5 of being off. Called the diabetes doc and she said that was okay will see her soon. I am still taking Actos bs numbers are inching up. Trying to exercise more. Got scared blood pressure went up. Now I’m on the couch. Also had tried Januvia and Onglyza made me depressed after a month. I was hoping metformin would be the answer. Pharmacist at Cleveland Clinic recommended Prandin or Starlix. Anybody have luck with either of those? I am so discouraged. KBG

  29. ss

    I’m having the same problem. Certain foods became off limits and now that I’m not taking it anymore, I still can’t have the foods! tops on the list is eggs, but I can also have trouble with salads (raw veggies) and even fried foods.

  30. G M

    Hope you are doing better now than you were in March. When I discontinued Metformin a year ago, after eight years of increasing indigestion, I was back to pre-2004 “normal” within a month. Hope your results were the same.

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