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As a type 2 diabetic, you’ve probably heard of Metformin, or you might even be taking it yourself.
Metformin (brand name “Glucophage” aka “glucose-eater”) is the most commonly prescribed medication for type 2 diabetes worldwide…and for good reason. It is one of the safest, most effective, least costly medication available with minimal, if any, side effects.
There are always lots of questions around Metformin – how does metformin lower blood sugar levels, does metformin promote weight loss or weight gain, will it give me side effects – and lots more.
Today we’ll hopefully answer some of those questions.
How Metformin Works
Metformin belongs to a class of medications known as “Biguanides,” which lower blood glucose by decreasing the amount of sugar put out by the liver.
The liver normally produces glucose throughout the day in conjunction with the pancreas’ production of insulin to maintain stable blood sugar.
In many people with diabetes, both mechanisms are altered in that the pancreas puts out less insulin while the liver is unable to shut down production of excess glucose. This means your body is putting out as much as 3 times as much sugar than that of nondiabetic individuals, resulting in high levels of glucose in the bloodstream.
Metformin effectively shuts down this excess production resulting in less insulin required. As a result, less sugar is available for absorption by the muscles and conversion to fat. Additionally, a lower need for insulin slows the progression of insulin resistance and keeps cells sensitive to endogenous insulin (that made by the body).
Since metformin doesn’t cause the body to generate more insulin, it does not cause hypoglycemia unless combined with a sulfonylurea or insulin injection.
Metformin is one of the few oral diabetes medications that does not cause weight gain and often people note a slight weight loss (although this is not its main action and not everyone experiences weight loss).
While the mechanism for this is not clear, it may be the result of less gluconeogenesis (making glucose) in the liver and/or decreased food intake, likely caused by increased satiety (ie. curbing appetite).
The Downside of Metformin
Despite its perks, there are some precautions to take when starting Metformin.
The main side effect is gastrointestinal (GI) upsets.
Unfortunately Metformin can cause nausea, stomach pain, bloating, diarrhea, and other GI upsets in about one third of people. The good news is that this generally goes away within a couple days or 2 weeks at most.
This GI upset is simply the body adjusting to the medication and in most cases, incrementing slowly per physician and pharmacy recommendation will help to minimize upset. It also helps if you take it at the same time daily with meals.
Be aware that poor blood sugar control itself (both high and low) can also cause GI distress, so optimizing your diet is key as well. If symptoms haven’t waned after a week or 2 of taking Metformin, contact your physician’s office to see if there is a better option to consider.
It’s also worth considering that in time, as you get you maintain better blood glucose control through diet and lifestyle, you may be able to reduce or stop taking Metformin altogether – as demonstrated in this case study.
Another thing to note is that Metformin can cause B12 deficiency over time. If you’ve been taking Metformin for several years, it is advisable to get a B12 blood test. This deficiency can easily be corrected through supplementation.
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Metformin’s Effectiveness
Metformin is generally not as effective at lower doses, but starting out with smaller doses (ie. 500 mg/day) and titrating slowly to 1,000 mg twice daily (maintenance) will help avert GI side effects.
It’s also recommended never to exceed 2,500 mg/day (maximum dose).
The effectiveness of Metfomin varies from person to person–with some, the initial dose is sufficient, in others, effect is not seen until the max dose is reached, and still in others it is minimally effective.
For many people, healthy diet and lifestyle are sufficient in controlling blood glucose and in others whose biology or hormonal signaling is altered as described above, medication may be required to achieve control – it’s always an individual thing.
Regardless of whether medication is a part of your healthcare plan, it’s always important to make healthy dietary choices including the restriction of carbohydrates, most especially those in the form of white starches (bread, pasta, potatoes, rice) and simple sugars.
Metformin Perks
In comparison with other diabetes medications, Metformin:
- Is weight neutral (and in some may result in slight loss)
- Does not cause hypoglycemia
- Has a significant glucose lowering effect (preventing onset of diabetes in up to 33% of people enrolled in CDCs DPP)
- No effect on bone loss (as with TZDs and possibly SGLT-2s)
- Protective against cardiovascular disease, cancer, stroke and dementia
- Is non injectable
- Is very cost effective
- Originated from a natural herb and traces its medicinal history back thousands of years
Who should NOT take Metformin
There are a few people for whom Metformin is contraindicated:
- If you are having an X-Ray or CT scan requiring dyes, you will have to temporarily stop taking Metformin
- Because Metformin is cleared by the kidneys, it is contraindicated in kidney disease
- Because Metformin works in the liver, it is contraindicated in liver disease
- In rare cases, Metformin can cause a life threatening condition called lactic acidosis (tell your doctor if you have liver, heart or kidney disease, or drink alcohol)
As with all medications, whether to take metformin should be a shared decision between you and your physician.
Remember to discuss your goals, current blood sugar control (including HbA1c), family history, length of time you have been diagnosed, and any symptoms you may have.
Keeping a diary/log of medications and symptoms along with a food and glucose journal is very helpful in troubleshooting and making informed decisions regarding your health care in the future.
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My blood sugar level is 114 brefore breakfast and after meal is 180
Hello Ali, I would look at what you are eating for breakfast to see if you are possibly eating too many carbohydrates.
I have taken metformin for a long time. My issue is bloating and gas. Because I’m trying hard to lose weight, I try to cut carbs but then I get severe diaherea. I need help. What can I do?
Hi Irene,
If you are dealing with significant digestive issues I would connect with a gastroenterologist to see if there are any underlying issues.
I had this problem and now use a time release type of metformin.
Hi I have been prescribed Metformin after doing a long time Glucose Test. Diagnosis is insulin resistance. Typically I never have high blood sugar but low blood sugar- I have to eat really often to maintain a value above 75mg/dl. After a huge healthy breakfast protein tiny bit of carbs and veg – I have to eat an hour later as my blood Sugar has sank to about 75 – if I don’t eat it keeps going down – by the time I reach 62mg/dl I feel awful. Mornings are the worst. I take L Thyroxine. Evenings are usually okay. Last night I took the fist Metformin and am having really bad sugar dips today and where it would usually be stable in afternoon it is also dipping. Do I need to give this time to regulate. Is this the correct medication for low blood sugar? My normal blood sugar 2 hours after eating is never higher then 100.
Would really appreciate some imput. Kind Regards Michelle
Any medication will take time for your body to adjust, however, you need to speak to your doctor Michelle. Metformin lowers blood glucose so if you are already having lows and it is causing more problems, this may not be the right medication for you.
My grandson was put on metfotmin by his Dr. he doesn’t have diabetes his blood sugar is slightly high he has some mental issues. and has gained a lot of weight in the last 2 yrs he told us this medication will keep him from gaining weight but will also keep him. from losing weight is this a good drug to take for that reason he is not a very big eater he just doesn’t do anything and is very hard to motivate to do anything before his issues started he was always thin and very active would appreciate yor input Thank You
Metformin doesn’t cause weight gain and some people experience slight weight loss. If your grandson’s blood sugar levels are slightly high, he may be in prediabetic range and metformin is often prescribed in these instances. If you have any concerns, please ask your grandson’s doctor for more info.
I’ve been taking metaformin for about 8 years now and know four other people that are on it. I can say with 100% certainty and direct personal experience that it does cause weight gain. My friends have experienced the same. I don’t know why the lab monkeys that do research studies say this isn’t true. They just have to monitor a diabetic chat room or support group to get this feedback. And before you say it, yes I am sure there was no other reason for it.
Thanks for sharing your experience, Dana. Health is super individualized for each person, meaning what works well for someone might effect another person completely differently. This includes the way our bodies react to medication, food, stress, exercise, etc. Hopefully you are able to work with your doctor to figure out what works best for your body and lifestyle!!
I have been taking metformin for almost a month now. I have lost about 16 pounds. I also use an app called my fitness pal to monitor calories and carbohydrates. It’s amazing how little you can eat certain things, thinking they are healthy and still gain weight. I had a friend complain she couldn’t lose weight, until I showed her exactly how many calories she was actually getting. She was guessing her serving sizes and was really way off. We love my fitness pal as a way to stay compliant.
Hi Leva,
That is great you have found something that works for you. Tracking can be a very beneficial tool that helps us stay mindful of our food choices!
I personally have lost exactly 100 pounds over the last year by controlling my prediabetes with healthy eating and Metformin.
Awesome story! Thanks for sharing, Lynn.
Good morning. I am taking metformin 1000mg with 15mg pioze last 10 years in the morning with breakfast only I am now 60 years.My fasting sugar is 150 and pp 156 after taking medicine in the morning with break fast.I am feeling tiredness in the day will you please suggest my diet plan and proper medication thanks
Regard
Shishir
Dehradun, India
We encourage people to follow a lower carb diet to help lower blood sugar and keep levels in a healthy range. You can find the diet guidelines here. As for medications, you need to discuss this with your doctor.
I love sandwiches and I would like to know what is a good choice of bread for me ? My BG is running 170 in the morning and the highest I have had 2 hours after eating is 261. My doctor gave me metformin er 500 mg once day but I have a lot of gas and GI troubles so I haven’t started it yet.Thanks
I quit smoking 11 years ago ( 2 packs a day) and have gained 100 lbs. I am at 250 lbs now. I have a bad back and knees, copd, high blood pressure along with the diabetes. Just thought I should add that information.
Sharon, most traditional bread available in the grocery store is high in carbohydrates and likely contributing to your high blood sugar levels. The good new is that you have a few other options and we’ve actually written a whole article about the best breads for diabetics over here.
You may also consider signing up for a Low Carb Breads Masterclass which includes 30+ recipes and videos for making your own low carb bread.
I was taking metformin for probably 15 or 20 years. Although it kept my type 2 diabetes under control, my doctors infomed me I had cirrhosis of the liver from taking it. I had the bariatric sleeve surgery, which cleared up the diabetes; however I am worried it will come back,and what do I do then. I am in stage 4 of cirrhosis.
Hi Nancy,
I am sorry to hear about this! It is best to discuss your plan of care with your physicians that know your medical history and can give you specific recommendations.
Natures own has an option with sugar free bread.
Hi Cynthia. The bread you described is much lower in carbs (9g carb, 1g fiber per slice) compared to many other commercial breads available in stores. For some, this may be a good alternative to bread, however we don’t encourage bread on our meal plans because for most people it’s easier to avoid than to moderate. Eating any type of bread, even when it seems like a “healthy” whole grain/ low calorie/ low sugar variety will really spike up your daily carb intake without you even realizing. Here are a few of our other bread substitutes you may find of interest!
I apologize since i dont take Metformin yet but i have been diagnosed with pregestational diabetes a cpl yrs ago …. Lately i have been going to docs with hubby and want to talk to her about my problems but it is his time with her not mine.
My questions is with my history should i worry about my blood sugar still being over a 100 five hrs after having a salad for dinner??? Carbs/sugar would have come from dressing or 3 bites of a sweet baguette.
How high over 100 are you typically observing? The guidelines we encourage are to maintain levels under 140 mg/dL post-prandial (2 hours after a meal.) Having a history of pregestational diabetes makes it even more important to stay on top of your numbers, you may find it helpful to check often so you can best observe the trends in your body.
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