Metformin Side Effects

Metformin is an ant-diabetic medicine that is in the biguanide class that was originally branded and sold as Glucophage. It is used to treat type 2 diabetes for people that are either obese or overweight, and still have their kidneys functioning properly. It works by repressing the production of glucose in the liver.

Although Metformin is quite widely used by the patients that have the above preconditions however, some individuals or patients do react to it badly, so its use for gestational diabetes is still very limited. There are presently a few research projects being conducted on it for insulin resistant patients who may find it beneficial. Some patients that have polycystic ovary syndrome are also treated with it.


Metformin has proven to possess many highly beneficial traits that most other drugs in this classification to not presently offer diabetes sufferers. It is known to decrease the triglyceride and LDL cholesterol levels, in addition to preventing cardiovascular complications of diabetes. At this time, it is the only drug that possesses each of the above very desirable characteristics, and it has not been shown to increase its user’s weight.

The World Health Organization Model List of Essential Medicines in 2010 included it as one of only two ant-diabetics that were essential in the fight against diabetes. Metformin is known to cause very few side effects when it is prescribed and administered correctly. The keyword in that sentence was “Correctly”, because in all too many instances, it is being used by patients that it is not intended for.

Its most common side effect is gastrointestinal upset and it is also associated with a low risk of hypoglycemia. It can cause lactic acidosis, which is a concentration of lactate that occurs in the blood stream, and it can develop into a serious issue when it is used by patients that should be avoiding it.

It was first discovered that it reduced blood sugar as far back as 1920, when it was initially synthesized. Shortly after that, it was forgotten about for a period of time as research shifted to other more promising approaches for treating diabetes. For the next two decades most of the medical studies were conducted on either insulin or other ant-diabetic medications.

In the 1940’s interest in metformin was reawakened after a few reports were published that stated it could decrease blood sugar levels in humans. The French physician Jean Sterne in 1957 conducted the first clinical trial on it as a possible treatment for diabetes. It is now believed to be the most widely used ant-diabetic in the world. It use in America started in 1995, before that it was prescribed in the UK as far back as 1958, and in Canada as early as 1972. For the year 2010 in the United States, over 48 million prescriptions were filled for its various generic formulations.

Today it is sold under the brand names metformin (Glucophage) or metformin ER (Glucophage XR). As with almost every type of drug or medication, there are side effects associated with their use, and this drug is no exception. Fortunately, they are usually very mild and can be easily treated by your physician or do not require any treatment at all. Below you will find a list of the most widely seen side effects connected to taking this drug.

The following estimates and percentages were obtained by extensively examining the records of the various clinical trials that have been conducted on metformin side effects. One of the most alarming statistics related to this drug is that up to 53.2% of the patients that take it, at some time will come down with diarrhea. As we all know, this disease can lead to many other very serious health conditions. Therefore, it is recommended that if you or somebody that you know suffers from it for only a few days that you immediately consult with your physician about a possible treatment.

Another serious side effect that is caused by metformin is vomiting or nausea. Reports show that up to 25.5% of the patients that use it, will experience this side effect. Once again, you should see your doctor if this occurs for a couple of days.

Some of the less serious side effects caused by metformin and their percentages of patients that will experience them are the following; gas or bloating 12.1%, feeling weak and lethargic 9.2%, trouble digesting food 7.1%, a stomachache 6.4%, and in 5.7% of the patient that use it will at some time or another get a headache.

There is some good news, which is the patients that take the longer lasting form of this drug metformin ER, suffer less side effects percentage wise. The following are a few of the side effects and their percentages, diarrhea 9.6% and vomiting 6.5%.

Besides the side effects that were mentioned above that you should see your physician about, if you suffer from any of the following you should also let them know; feeling exhausted or feeble, pain in any of your muscles, feeling cold or sweating when you are sleeping, difficulty breathing, faintness or wooziness, or you suspect that your heart is not beating properly.

metformin side effects Some scientists that study metformin believe that there are other possible side effects associated with its use. However, these side effects have not been proven yet beyond a shadow of doubt. They occur in approximately 1% to 5% of the patients that use it and they are the following; problems with your nails, changes in the way foods taste, your face turning red, heart palpitations, and cold or flu like symptoms such as chills, fever, or constantly feeling exhausted.

There is little doubt that metformin has been some kind of wonder drug for the patients that suffer from diabetes. However, it is not right for everybody, and it should not be utilized without a doctor first checking you over, and prescribing it for you. The side effects associated with its use for the most part can be controlled if the patient notices them soon enough, and contacts their doctor right after they detect something is not quite right.

Metformin is a well researched medication for the treatment of type 2 diabetes. All medications have the possibility of side effects, but not all persons taking a drug will have side effects, nor will they have the same exact side effects. Clinical studies have indicated the most common metformin side effects and they are listed below. Metformin has been shown to be a fairly safe medication, with few side effects, and if any side effects occur, they are usually handled well by self care or under the care of a competent physician. In fact, most people tolerate the drug well, with little discomfort.

All drugs used in the USA for clinical practice, require passage of FDA testing. During the testing, side effects are documented and listed. Not all the noted metformin side effects are mentioned here. For a complete list, you can consult your doctor.

Most Common Metformin Side Effects

Since metformin and metformin (extended release) ER tablets have been studied thoroughly with many people, the sample size was considered robust. This means that such a large number of people tried the medication that the results are more proven and that the conclusions should be considered to be more valid. The studies were always compared to a group of people who were not taking the drug. The ER version of the drug was found tohave the lowest incidence of reported side effects.

The most common metformin side effects included: Diarrhea – occurred in up to 53.2 percent of the sample; Nausea or vomiting – in up to 25.5 percent of the sample; Gas – in up to 12.1 percent of the sample; Weakness – in up to 9.2 percent of the sample; Indigestion – in up to 7.1 percent; Abdominal discomfort (or stomach discomfort) – in up to 6.4 percent; and, Headache — in up to 5.7 percent.

The side effect profile for metformin ER was much lower. Common side effects for metformin ER included diarrhea (in up to 9.6 percent of people) and nausea or vomiting (in up to 6.5 percent of people). You should always tell your doctor you are taking metformin if you are about to undergo any scanning procedures or xrays in a healthcare setting.

There is a very rare, but very serious side effect that can occur while taking metformin. The condition is called Lactic Acidosis. If you are having any of these symptoms: increased sleepiness or unexplained lethargy, weakness, decreased or slowed heart rate, cold sensations, stomach pains, or if you are feeling light headed or have fainted either before or after taking metformin you could be showing some of the symptoms of lactic acidosis. This is a dangerous syndrome and you should seek emergency medical help right away.

Chest pain has been reported and other metformin side effects such as flushing, red face, etc. You should also be concerned if you are allergic to metformin or have allergic reactions after taking it. Allergic reactions can be marked by rashes, hives, itching, difficulties with breathing, or unexplained swelling.