People with type 2 diabetes (T2D) should not stop taking metformin without speaking with a doctor first. They can assess if this is safe, or provide alternative medications a person may be able to take instead.
Metformin is a drug that helps to control the amount of sugar in the blood for people with T2D. In people with prediabetes, the drug can also help prevent or delay the onset of the condition.
However, metformin may not be suitable for everyone and can cause side effects, such as digestive problems.
A healthcare professional can advise on ways of reducing side effects from metformin, or if appropriate, using another treatment approach to manage blood sugar levels.
Metformin is an effective treatment for T2D. It is often the first-line drug therapy for the condition, and helps to lower blood glucose levels by:
- making the body’s cells more sensitive to insulin
- slowing the release of glucose stored in the liver
- slowing the absorption of glucose from food in the gut
However, metformin has a number of
Common side effects of metformin can include:
- digestive problems, such as diarrhea, vomiting, and flatulence
- abdominal discomfort
- headaches
- lack of energy
Taking the medication with food may help reduce the risk of digestive problems.
Less common side effects
In some people, metformin causes blood glucose levels to drop too low. The medical term for this is hypoglycemia. Hypoglycemia is more likely to occur if a person is taking other diabetes medications, such as insulin, as well as metformin.
There is also a very low risk of developing lactic acidosis. This is when lactic acid builds up in the blood. When it occurs due to metformin, it is known as
Certain people taking metformin may also have a risk of kidney damage. A
Some people with T2D may want to stop taking metformin due to the side effects, a wish to manage the condition through lifestyle changes, or to avoid the long-term use of a medication.
However, a person should talk to a doctor before stopping metformin treatment for any reason. Stopping abruptly without another way of managing blood sugar may cause an increase in levels.
Lifestyle changes that may help to manage T2D include:
- Exercising regularly: According to a 2022 statement from the American College of Sports Medicine, various types of physical activities can not only enhance health, but also help manage sugar levels due the glucose-lowering effects of exercise.
- Making dietary changes: A
2020 reviewTrusted Source notes that a combination of diet and exercise can lead to T2D remission in some people. Specifically, a low carbohydrate diet may help with T2D. - Maintaining a moderate weight: In a
2018 studyTrusted Source , almost half of the participants reversed their T2D and stopped their antidiabetic medications by following a 12-month weight loss program.
When a person chooses to stop taking metformin, or any other antidiabetic medication, there is a risk of symptoms becoming worse.
Left untreated, high blood glucose levels can lead to complications, such as:
- impaired vision, or diabetic retinopathy
- kidney problems, or diabetic nephropathy
- nerve damage, or diabetic neuropathy
- heart problems
- sexual health issues
- foot problems
It is therefore essential that people consult a doctor first.
A doctor will often use certain criteria to determine whether it is safe for an individual to stop taking metformin. These criteria may include:
- having a fasting or pre-meal blood glucose level of 80 to 130 milligrams per deciliter (mg/dL)
- having a random or after-meal blood glucose level of under 180 mg/dL
- having a hemoglobin A1c result of under 7%
If a person meets these criteria, a doctor may help provide advice about continuing to manage their health with the right diet and exercise plans.
They can help set realistic goals and provide monitoring and support. If necessary, they can also refer a person to a dietician or another specialist for guidance.
If a person does not meet the criteria, a doctor may help a person meet them through diet, weight management, and regular exercise. Alternatively, they may suggest other treatments.
Alternatives to metformin may include:
Dipeptidyl peptidase 4 (DPP-4) inhibitors
These medications may help to improve A1C scores without causing hypoglycemia. They work by preventing the breakdown of glucagon-like peptide 1 (GLP-1) and gastric inhibitory peptide (GIP) by an enzyme known as DPP-4.
GLP-1 and GIP are natural hormones that help to reduce blood glucose levels in the body. As such, using DPP-4 inhibitors allows these hormones to remain active for longer. Typically, DPP-4 inhibitors are well-tolerated.
GLP-1 and dual GLP-1/GIP receptor agonists
Both GLP-1 and GIP are natural hormones that can help to regulate glucose levels. These medications have a similar effect to the natural hormones, but are resistant to being broken down by DPP-4. These drugs can help to lower blood glucose and may also aid weight loss and help prevent heart disease.
Examples of GLP-1 receptor agonists include Trulicity, Byetta, and Ozempic. Currently, the only dual GLP-1/GIP receptor agonist available is Mounjaro.
Sodium-glucose cotransporter 2 (SGLT2) inhibitors
Glucose in the blood passes through the kidneys, where the body either excretes it in urine or reabsorbs it back into the blood. SGLT2 helps to reabsorb glucose in the kidneys. As such, SGLT2 inhibitors block this action, helping the body to eliminate excess glucose in the urine.
These drugs may help to improve blood glucose levels, aid weight loss, and decrease blood pressure. A doctor may prescribe them for individuals with T2D who also have heart or kidney problems. However, they may increase the risk of genital yeast infections.
Sulfonylureas
These drugs help to stimulate the beta cells in the pancreas to release more insulin. All sulfonylurea drugs have similar effects on blood sugar levels, but differ in side effects, drug interactions, and how often people take them. Common side effects may include hypoglycemia and weight loss.
Examples include Amaryl and Glucotrol XL.
Thiazolidinediones (TZDs)
These drugs help insulin to work better in muscle and fat and also reduces glucose production in the liver. TZDs can help lower blood sugar without a high risk of hypoglycemia. However, drugs in this class can increase the risk of heart failure in some people, and may also cause fluid retention in the legs and feet.
Some FAQs about metformin include:
The most common side effects of metformin are stomach problems, such as diarrhea, nausea, vomiting, and gas.
Doctors still often prescribe metformin to help treat T2D. However, metformin may not be suitable for everyone with T2D. For example, a doctor may prescribe alternative treatments, such as SGLT2 inhibitors, in people with kidney problems.
Metformin does not harm the kidneys. However, if a person has kidney problems, they are more likely to experience complications from metformin, such as lactic acidosis.
When taking metformin, it is advisable to avoid or reduce certain foods, such as processed foods and those high in saturated fats, trans fats, sodium, and sugar. It is also advisable to avoid certain medications, such as diuretics and medication to treat heart problems and hypertension.
People with type 2 diabetes may be able to stop taking metformin with the supervision of a doctor. However, to prevent blood sugar from rising, they may need to make changes first.
A doctor may suggest dietary changes, physical activity, or weight management as a way of managing T2D. In some cases, this can cause T2D remission, which can mean a person no longer needs metformin.
For others, alternative drugs to metformin may be preferable, but a person must discuss this change with a doctor before stopping metformin or altering their dose.
