If you live with type 2 diabetes, your body doesn’t produce enough insulin or doesn’t use the available insulin properly, leading to elevated blood sugar levels.

There are many options for treatment available, including managing your condition with diet and exercise alone, opting to take insulin, or you may be given a drug called a Sulfonylureas to be included in a healthy lifestyle. 

But what are Sulfonylureas? 

This article will explain what they are, how they’re prescribed, the pros and cons of taking Sulfonylureas, and everything else you need to know if you choose to include this drug into your diabetes management plan. 

What are Sulfonylureas?

Simply put, Sulfonylureas are a group of medicines used to treat patients with type 2 diabetes. 

This type of medication has been around since the 1950s and works by increasing the amount of insulin that’s released from the pancreas, helping to lower blood sugar levels in patients. 

What are some common types of Sulfonylureas? 

Some of the most commonly prescribed Sulfonylureas include:

  • Tolbutamide
  • Diabinese (chlorpropamide) 
  • Amaryl (glimepiride) 
  • Micronase, Glynase, or DiaBeta (glyburide or glibenclamide) 
  • Glucotrol (glipizide)
  • Tolinase (tolazamide) 

Oftentimes, Sulfonylureas are combined with other medications, especially Metformin

How do you take a Sulfonylurea?

Sulfonylurea is a medication taken orally either with or before a meal (ideally, 30 minutes before a meal). They are usually taken once or twice a day (before breakfast or before both breakfast and dinner). If you miss a dose, just take your next dose as soon as you are able. 

Most patients start on a low dose of a Sulfonylurea, and if glucose targets are not met within two weeks, a physician can help you gradually increase your dose. 

Increasing your dose too quickly without a doctor’s supervision can cause dangerous side effects, including extremely low blood sugar levels that can be fatal. 

Storage instructions

Any oral Sulfonylurea should be stored at room temperature: 68°F to 77°F (20°C to 25°C) in a dry, safe place, out of the reach of children. Refill your prescriptions often, to avoid taking expired medications that may not be as effective. 

What are the common side effects of Sulfonylureas? 

Since these medications increase the amount of insulin that’s released from your pancreas, side effects can oftentimes feel and look like low blood sugar. 

The following are common side effects of this medication:

  • Low blood sugar, including shakiness, dizziness, confusion, and sweating 
  • Increased hunger
  • Weight gain 
  • Dark colored urine
  • Skin rashes and/or hives 
  • Upset stomach 

Several rare, but serious side effects may include: 

  • Heart attack
  • Stroke
  • Death 

Always check with your doctor before beginning any new medication regimen. 

The benefits of taking Sulfonylureas

If you live with type 2 diabetes and struggle with high blood sugar levels, elevated hba1c readings, and insulin resistance, taking a Sulfonylurea may be the right option for you. 

Always check with your doctor first, but one of the main benefits of taking a Sulfonylurea is improvement in blood sugar levels and hba1c readings. Some other benefits of taking a Sulfonylurea include: 

  • Decreased likelihood of experiencing diabetes complications, such as amputations, blindness, heart disease, stroke, and premature death (due to improved blood sugar levels) 
  • Increased energy levels 
  • Improvement in appetite 
  • Weight gain, if underweight 
  • They are an affordable option to help lower blood sugar levels and hba1c readings, if other therapies are too expensive 

The dangers of taking Sulfonylureas 

There are some negative consequences associated with taking Sulfonylureas that patients need to be cognizant of. 

Liver and kidney issues: Sulfonylureas may exacerbate existing liver and kidney problems; check with your doctor if you have such issues and wish to take a Sulfonylurea 

Light sensitivity: Some Sulfonylureas may cause one to be more sensitive to sunlight; always wear sunscreen and avoid unnecessary, direct contact with sunlight to avoid sunburns if you take a Sulfonylurea

Not recommended for people who are obese or are looking to lose weight: Since Sulfonylureas increase insulin production from the pancreas and may cause weight gain, they are not recommended for people who are looking to lose weight or for people who are currently obese, as the medication can exacerbate these issues

Some studies have found that starting Sulfonylureas as a second-line drug to treat type 2 diabetes increases one’s risk of myocardial infarction (heart attack) and all-cause mortality. The study recommends that if a patient is already on Metformin to simply add a Sulfonylurea treatment plan to their existing drug regimen instead of changing to using only a Sulfonylurea

Sulfonylureas can cause dangerously low blood sugar levels in patients. Be sure to always wear a medical ID bracelet, carry fast-acting glucose with you at all times, and that you can feel low blood sugars coming on before it becomes an emergency. Be cognizant of hypo-unawareness, which can be common 

If you develop an allergic reaction to a Sulfonylurea, call 911 immediately and seek emergency medical attention. 

You are encouraged to report any negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088. 

What to be cautious of when taking a Sulfonylurea 

Taking a sulfonylurea is not for everyone. People with type 1 diabetes and those who experience diabetic ketoacidosis (DKA) often should not take the medication. 

There are several other groups of people who need to be cautious when taking this medication: 

  • If you drink alcohol regularly and/or heavily, it may worsen the side effects of a Sulfonylurea. Check with your doctor before starting a Sulfonylurea regimen and do not drink alcohol when taking the medication
  • Women who are planning on becoming pregnant, are pregnant, or are breastfeeding should check with their doctors before starting a regimen of Sulfonylurea. Due to the lack of random control trials (RCTs) and other studies on those who are pregnant, the side effects of Sulfonylurea are unknown in this population and should be closely monitored by your doctor.
  • People who struggle with hypo-unawareness (not physically feeling their low blood sugars before they reach dangerous levels) may struggle when taking this medication because it can cause low blood sugars

Check with your doctor to see if getting a continuous glucose monitor (CGM) or diabetes alert dog to help you track your low blood sugars, may be helpful for you. Always carry a medic alert ID on you along with fast-acting glucose in case of a low blood sugar emergency. 


Since they were discovered in the mid-20th century, patients have been taking Sulfonylureas to help manage their blood sugar levels, if they struggle with insulin resistance and type 2 diabetes. 

This commonly prescribed, affordable drug can vastly improve one’s hba1c and improve quality of life. 

However, there are many contraindications with these drugs that may not make them suitable for everyone. Most notably, they may increase the risk of heart attack, all-cause mortality, and severe hypoglycemia (low blood sugar). 

Always work with your doctor and care team to see if taking a Sulfonylurea may be an appropriate addition to your diabetes management and therapy.