Metformin can be used alone or in combination with other medicines to treat Type 2 Diabetes mellitus. It is not used to treat type 1 diabetes.
First of all what does this medicine do in the human body.

Metformin helps to control the amount of glucose (sugar) in your blood. It does this in three main ways:
1.It decreases the amount of glucose you absorb from the food you eat and
2.It decreases the amount of glucose made by your liver.
3.Metformin also helps your body to respond better to insulin natural or injected.

Only your doctor can tell you how much Metformin and how many times a day you need to take. Do not take more or less of it than what your doctor has prescribed. Metformin controls diabetes but does not cure it. Continue to take metformin even if you feel well. Do not stop taking metformin without talking to your doctor.

Not everyone who takes metformin is a Type 2 diabetic. Metformin may be prescribed for other uses; ask your doctor for more information regarding this.

Once you start eating metformin you cannot start eating whatever food you like and stop doing any exercise. Diabetes treatment can only work when the person who has diabetes eats the medicines on time and also eats the correct amount of the correct food at the correct time and exercises at least 30 min a day 5-7 days a week.

In case you forget to take a dose take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Metformin may rarely cause a serious, life-threatening condition called lactic acidosis.
Drinking alcohol increases your risk of developing lactic acidosis or may cause a decrease in blood sugar. Ask your doctor how much alcohol is safe to drink while you are taking metformin.
Side effects from metformin include a change in taste, loss of appetite, nausea or vomiting, abdominal bloating or gas, diarrhea, or skin rash. These may occur during the first few weeks of taking the medication but are seldom long-lasting. Taking the medication with food and starting out with a low dose help reduce side effects. The dosage can be gradually increased as side effects diminish.

Metformin may rarely cause low blood sugar levels or hypoglycemia.
Your doctor will tell you what you should do if you develop hypoglycemia. He or she may tell you to check your blood sugar, eat or drink a food or beverage that contains sugar, such as hard candy or fruit juice, or get medical care. Follow these directions carefully.
The following are symptoms of hypoglycemia:

1.shakiness
2.dizziness or lightheadedness
3.sweating
4.nervousness or irritability
5.sudden changes in behavior or mood
6.headache
7.numbness or tingling around the mouth
8.weakness
9.pale skin
10.hunger
11.clumsy or jerky movements

If hypoglycemia is not treated, severe symptoms may develop. Be sure that your family, friends, and other people who spend time with you know that if you have any of the following symptoms, they should get medical treatment for you immediately:

1.confusion
2.seizures
3.loss of consciousness

Therefore who should not use metformin? In a nut shell, it should not be used by those who use more than two ounces or two drinks of alcohol everyday day, who have congestive heart failure, or who have significant kidney, liver, or lung disease.

The advantages of metformin are that it has a much short action time and has a much lower risk for severe side effects and is quite safe for use by anyone who is otherwise healthy. In fact, in the major UKPDS study, it was the only drug that reduced diabetes-related death rates, heart attacks, and strokes.
Metformin lowers fasting blood glucose levels by an average of 25%, postprandial blood glucose up to 44.5%, and the HbA1c by an average of 1.5%. Metformin reduces raised plasma insulin levels in cases of metabolic syndrome by as much as 30% and reduces the need for injected insulin in Type 2s by 15 to 32%.

Metformin possesses some distinct advantages in treating diabetes. Excess glucose produced by the liver is the major source of high blood sugars in Type 2 diabetes and is typically the reason for high blood sugars on waking in the morning. Metformin reduces this overproduction of glucose. It helps in lowering the blood sugar, especially after eating, with no risk of hypoglycemia when used alone. Modest improvements in cholesterol levels are also seen. The 10 year UKPDS Study of over 3,000 people with Type 2 diabetes found that those who were placed on metformin had a 36% decrease in overall mortality and a 39% decrease in heart attacks.
Because metformin shuts off the liver's excess production of glucose, it reduces the amount of injected insulin needed to control the blood sugar in both Type 1 and Type 2 diabetes. People with Type 2 diabetes who are on insulin usually are advised to lower their insulin doses prior to starting metformin. The full improvement in glycemic control and cholesterol levels may not be seen until 4 to 6 weeks of use have passed.

Dr Sherry is a Medical Domain Specialist at Yos Technologies. For reliable information about Diabetes, Diet and  steps to control diabetes effectively please visit the website.