What is Metformin?

Metformin is a medication that can be used alone or in conjunction with other medications to treat type II diabetes.

Type II diabetes is a medical condition in which a person cannot regulate the amount of glucose, or sugar, in their blood. In type II diabetes, the person is still able to produce the glucose regulating hormone insulin, but the body is resistant or has trouble using the insulin.

When a person has insulin resistance their body builds up sugar in the bloodstream because their cells do not want to use the insulin making it harder for the body to absorb that sugar.

The Benefits of Metformin

woman talking to doctorMetformin provides three advantages in the battle against type II diabetes. The first benefit metformin provides is more control over the amount of glucose in the bloodstream. With the better control provided by metformin,  the patient is able to lower the amount of glucose in the blood if they are experiencing hyperglycemia (high blood sugar) or able to keep their blood sugar levels within a safe range more easily.

The second benefit is the effect metformin has on the food you eat. Metformin helps to decrease the amount of glucose you get from food and decreases the amount of glucose that your liver produces. This effect directly helps your glucose control by lowering the amount of glucose you are creating.

The third benefit has great synergy for a patient with type II diabetes. Metformin makes the body more receptive to insulin thus decreasing the patient’s natural insulin resistance. This means that more of the insulin that has been released into the bloodstream with be effectively used by cells.

There have been various studies done to observe the effects of metformin and they tend to show that metformin is an effective drug for lowering blood glucose levels.

In a 24-week study conducted by Hoffmann, J., and Spengler, M. from the Medical Department, Bayer AG, Leverkusen, Germany, found that both the blood glucose and HbA1c numbers were at more acceptable levels with metformin use when compared against a placebo.

Researcher at the Baylor College of Medicine also found that metformin lowered a fasting blood glucose reading and HbA1c levels. In this study, however, they measured different dosages of metformin ranging from 500mg to 2000mg dosages. The study found that all dosages levels are well tolerated, meaning there were few side effects. The biggest side effect was an increase in the occurrence of diarrhea and other digestive troubles.

Additional Benefits

Metformin is not only for people with type II diabetes. In the article “Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin” by the Diabetes Prevention Program Research Group, metformin use was found to lower the occurrence of type II diabetes when compared to a placebo group. Research is ongoing, but metformin has also been linked to helping with other conditions. Studies anticipate that metformin can help with slowing the aging process, increasing a person’s life span, and fighting certain types of cancer.

Side Effects of Metformin

Metformin is a medication and, like all medication, has possible side effects that may be experienced by the user. Below is the full list of possible side effects associated with metformin. The most common side effect of metformin is gastrointestinal distress, which include diarrhea, nausea, and vomiting. Other common side effects are decreased appetite, muscle pain, and sleepiness.


  • Antidiabetic – a drug used to treat diabetes mellitus
  • Biguanide – orally administered agents used in the treatment of type 2 diabetes, which prevents the liver from breaking down glycogen into glucose and increases the sensitivity body tissues have to insulin


  • Tablet
  • Sustained release tablet
  • Oral solution


  • Metformin is taken with meals or shortly after meals
  • If taking the oral solution, use a calibrated oral syringe or container to measure the oral solution for accurate dosing

Therapeutic Effects

  • Antihyperglycemic – A substance or therapy that counteracts high levels of glucose in the blood.


  • Treatment of type 2 diabetes mellitus alongside diet and exercise.


  • Hypersensitivity (or allergic reaction) to Metformin.
  • Hepatic or Cardiopulmonary insufficiency (Liver or heart not functioning normally)
  • Alcoholism
  • Concurrent infection
  • Acute MI – Myocardial Infarction (Heart Attack), Cardiogenic shock
  • Diabetic Ketoacidosis
  • Metabolic Acidosis
  • Hypoxemia, lactic acidosis
  • Radiographic contrast administration
  • Renal disease, renal failure, renal impairment 

Cautious Use

  • Previous hypersensitivity to phenformin or buformin
  • Anemia
  • Coma
  • Dehydration, diarrhea
  • Fever
  • Gastroparesis (Disease of the muscles of the stomach or the nerves controlling those muscles that cause the muscles to stop working; Stomach paralysis)
  • Heart failure
  • Polycystic ovary syndrome (An illness characterized by irregular or no periods)
  • Trauma
  • Vomiting
  • Older adults
  • Children younger than 16

Patient Education

  • Hypoglycemia is not a risk when drug is taken in recommended therapeutic doses unless combined with other drugs which lower blood glucose
  • Report to prescriber immediately of infection, which increase the risk of lactic acidosis (Abdominal pain, nausea, vomiting, anorexia)
  • Avoid drinking alcohol while taking this drug

Immediately report the following

  • Severe vomiting
  • Diarrhea
  • Fever
  • Any illness that causes limited fluid intake

Comprehensive List of Side Effects for Metformin

  • Severe vomiting
  • Diarrhea
  • Fever
  • Any illness that causes limited fluid intake

Body – These effects can appear anywhere in the body.

  • Hypersensitivity (Allergic Reaction)
  • Chest Pain
  • Chills
  • Flushing
  • Fever
  • Muscle Pain

Cardiovascular – These effects pertain to the heart and circulation.

  • Chest Discomfort
  • Flushing
  • Palpitation

Gastrointestinal – These effects are found in the digestive tract which begins at the mouth, goes through the stomach, and ends with the intestines and rectum.

  • Nausea
  • Diarrhea
  • Vomiting
  • Feeling Bloated
  • Abdominal pain
  • Anorexia
  • Bitter or metallic taste in mouth
  • Malabsorption of amino acids
  • Vitamin b12 and folic acid possible
  • Flatulence
  • Indigestion
  • Abnormal Stools
  • Dyspepsia

Endocrine – These effects are to the hormone secreting glands within the body.

  • Lower TSH levels

Hematologic – These effects are disorders which affect the blood.

  • Lower B12 levels

Musculoskeletal – These effects impact muscles and bones.

  • Muscle Pain

Central Nervous System – These effects impact the brain, spinal cord, and nerve messages throughout the body.

  • Headache
  • Dizziness
  • Agitation
  • Taste Disturbances
  • Fatigue

Skin – These effects impact the skin.

  • Rash
  • Nail Disorder
  • Increased Sweating
  • Erythema
  • Pruritis
  • Urticaria

Metabolic – Affect the body’s metabolism.

  • Lactic Acidosis – occurs when cells make lactic acid (from glucose) faster than it can be metabolized

Gastrointestinal – These effects are found in the digestive tract which begins at the mouth, goes through the stomach, and ends with the intestines and rectum

  • Nausea
  • Diarrhea
  • Vomiting
  • Bloatedness
  • Abdominal pain
  • Anorexia
  • Bitter or metallic taste             
  • Malabsorption of amino acids
  • Vitamin b12 and folic acid possible

Respiratory – Affects the respiratory tract (nose, nasal passages, nasopharynx, larynx, trachea, bronchi, and lungs)

  • Rhinitis

Hepatic – Affecting the Liver

  • Abnormal liver function tests
  • Hepatitis