Side Effects of Metformin

Lactic Acidosis

This is one of the most dangerous side effect of Metformin, lactic acidosis happens when there is an big amount of lactic acid in the person’s bloodstream. This would most likely happen with patients with certain medical conditions, such as kidney or liver disease, recent surgery, infections, heart conditions, heavy alcohol use and dehydration. Symptoms of lactic acidosis would include feeling tired or weak, difficulty in breathing, dizziness or lightheadedness, irregular heartbeat or tachycardia, shortness of breath, frequent nausea, abdominal pain, an enlarged or tender liver, and feeling cold, blue or cold hands and feet. Guess the Emoji SolutionsThose these symptoms may sound scary, this complication is very rare. If the patient is generally healthy, then he or she can take the excess amounts of lactic acid in his or her body. Though this may be the most serious side effect, lactic acidosis is also very uncommon among patients who use Metformin. According to a large-scale study, out of 10,000 diabetic patients, who have been treated with Metformin for over 10 years, only 10 will die of lactic acidosis. This is a fairly small number as compared to the 500 diabetes related deaths that Metformin would have prevented.

Allergic Reaction to Metformin

There might be an allergic reaction to some patients from the use of Metformin and it is necessary to be very careful to these allergic reactions as they would need immediate treatment at once. Allergic reaction to Metformin will cause difficulties in breathing and hives. Swelling can also be an allergic reaction to Metformin; swelling can happen in the face, lips, throat or tongue.


Hypoglycemia or a condition of low blood sugar happens once the sugar level in your blood drops to a level that is too low for your body’s needs. Symptoms of this condition would come with excessive sweating, shakiness, extreme hunger, cold sweats, indistinct vision, erratic changes in behavior, problem with speech and seizures. Although Metformin is a drug for diabetics in order to reduce their blood sugar levels, too low sugar levels within the blood are not healthy either. Individuals experiencing these symptoms should ingest any food with sugar content in it, such as hard candy, or juice. This is to prevent any further damage or more severe effects to occur.


Another serious side effect of Metformin is Hyperglycemia or a fast increase of sugar content in the blood. The main symptoms of this condition would be the patient to be very hungry, to have a dry mouth, to feel very thirsty, frequent urination, the vision would be blurred, not able to breathe well and nausea or vomiting. The necessity of this condition is to be treated right away, or else the body might experience diabetic ketoaicidosis. This would inhibit breathing and might even lead the patient to pass out after a few moments.

Nerve Damage

Though Metformin has a lot of advantages, it may additionally cause permanent nerve damage. Three out of ten individuals might experience this due to a deficiency in vitamin B12, which is one of the Metformin side effects. B12 vitamin is normally absorbed in the portion of the small intestine called the ileum. To be adequately absorbed, it binds to a protein referred as intrinsic factor, which is needed for it to be transported across the intestine and into the bloodstream. Metformin side effects include interference with the absorption of this vitamin B12-intrinsic factor complex, leading to a deficiency once liver stores of vitamin B12 are used up.
Vitamin B12 deficiency takes about 10-15 years before the symptoms are detected, and by that time, then the damage would have been irreversible. These signs of nerve damage can be sometimes mistaken as diabetic neuropathy, which is why it can go untreated and eventually become permanent.

Fatigue and Muscle Pain

Metformin might cause in some cases especially in men fatigue and muscle pain. Individuals may feel more sleepy and tired than usual. Getting additional sleep during the night and taking a mid-day nap may help combat fatigue related with Metformin. Muscle pain may occur while taking Metformin. Patients should consult their doctor regarding the use of a non-steroidal anti-inflammatory drug such as ibuprofen for the occasional relief of muscle discomfort. Severe muscle pain should be brought to the attention of a doctor.

Gastrointestinal problems

Even this is not the most serious of side effects of Metformin it can still cause extreme discomfort. These are some of the symptoms of gastrointestinal discomfort: nausea, cramps, vomiting, diarrhea and it is often comes with flatulence. Luckily these side effects are most common when the drug is first prescribed or when the dosage is modified. For this reason the first dose is often fairly low and will slowly be increased to the required levels. This way the body of the patient has the time to react to the changing circumstances. Once the patient is used to the required dose they are unlikely to keep experiencing these adverse effects. However, one problem that can manifest itself after prolonged usage of Metformin is that B12 can no longer be properly absorbed. This will lead to a B12 deficiency and a close eye needs to be kept on long term patients for this reason. A prolonged B12 deficiency can cause damage to the nerve system. The symptoms will usually only manifest themselves after a decade and in some cases even longer. By that time the damage can already be irreversible. As a B12 deficiency is often hard to detect, usually preventative measures are taken to avoid this fairly serious side effect.

Metformin Effects in Children

If Metformin is been taken by children, then possibilities are that they might experience a number of these effects as well. According to research, Metformin can have the same effects on children as with adults. But since children cannot interact with these kind of symptoms as well as adults, they have to be given special care and also medical attention immediately, whenever these effects occur.

Preventing nerve damage when taking Metformin
If you’re taking Metformin, you should ask your doctor to check the level of vitamin B12 through a blood test at least once a year. If your levels are low, you will be able to get B12 injections every month to bring them back up and decrease your risk of B12 neuropathy and nerve damage. Handle this issue along with your doctor before taking Metformin – and ask your doctor to check a B12 level before you start taking it to serve as a baseline. Older individuals and vegetarians are at high risk for vitamin B12 deficiency too since vitamin B12 isn’t found in most plant foods. If you take Metformin – take it safely to avoid side effects. Don’t risk permanent B12 nerve damage.

Avoid Alcohol

It’s advisable to not drink alcohol while you are under Metformin, especially if you have decreased kidney function, liver function or have a history of lung issues. If you’re on the other hand healthy, an sporadic drink usually won’t cause any issues, but talk to your doctor before drinking alcohol while Metformin. If you are drinking a lot and frequently this will increase the risk of lactic acidosis. Don’t run a risk with your health.

Metformin and Pregnancy

Metformin is safe to take during pregnancy and doesn’t pose a risk to mother or fetus, and it may have benefits for women with polycystic ovary syndrome by reducing their risk of miscarriage as research suggests. Still, more research is needs to be done. Get advice from your doctor about whether you should take Metformin if you’re pregnant or plan on becoming so.

Symptoms of overdose may include hypoglycemia symptoms as well as the following:
• extreme tiredness
• weakness
• discomfort
• vomiting
• nausea
• stomach pain
• decreased appetite
• deep, rapid breathing
• shortness of breath