Pills vs. Insulin for Diabetes Treatment

Medically Reviewed by Michael Dansinger, MD on March 16, 2023
4 min read

If you have type 2 diabetes and things like exercise and healthy eating haven't done enough to help, you might need medication to get your blood sugar where it needs to be.

There are two main types of medication for type 2 diabetes: pills and insulin. Both help your blood sugar stay close to normal. That’s important, because if it's high, it can lead to things like nerve damage, vision problems, kidney problems, heart disease, and amputation.

Which type of medicine is right for you? There are things you should know before you talk it over with your doctor.

If you’ve just found out you have type 2 diabetes, your doctor will probably recommend that you take pills to manage your blood sugar. There are several different types. They don’t replace insulin. But they can help your body:

  • Make more insulin
  • Use it more effectively
  • Lower your blood sugar

Your doctor may prescribe one or more of the following:

Metformin (Glucophage) is usually the first pill that doctors prescribe for type 2 diabetes. (You can take it as a liquid, too.) Metformin lowers the amount of blood sugar that your liver makes and helps your body use insulin more effectively. You might use other diabetes medications along with it. It may also help you lose a little bit of weight.

You may not be able to take metformin if you have liver disease, kidney problems, or heart failure, or if you drink heavily. In those cases, it can cause low blood sugar and a condition called lactic acidosis, which can be dangerous. 

Sulfonylureas are a type of medicine that helps your body make more insulin. Examples include:

They can cause weight gain and low blood sugar.

Meglitinides help your pancreas release more insulin. They usually do it faster than sulfonylureas, but they don't work as long. Examples include repaglinide (Prandin) and nateglinide (Starlix). Side effects of meglitinides include low blood sugar and weight gain.

Thiazolidinediones make your body’s tissues more sensitive to insulin. That helps your body use it more effectively. Examples of this type of medicine include rosiglitazone (Avandia) and pioglitazone (Actos). They're usually only prescribed if other treatments don't work. That's because their side effects can be severe, including heart failure and anemia.

Dipeptidyl-peptidase 4 (DPP-4) inhibitors lower blood sugar levels slightly, but not as much as many other diabetes drugs. Medications that fall into this class include:

They can cause joint pain and raise your chances of pancreatitis (an inflamed pancreas).

Sodium-glucose cotransporter-2 (SGLT2) inhibitors keep your kidneys from absorbing glucose. Instead, it goes into your urine. That lowers your blood sugar.

Examples include:

SGLT2 medications may lower your odds of heart attack and stroke. They may also help slow the progression of kidney disease. Side effects include yeast or urinary tract infections, low blood pressure, and a higher chance of something called diabetic ketoacidosis. That's when your body creates high levels of blood acids called ketones.

GLP-1 Receptor Agonists (your doctor may call them incretin mimetics) are medicines that help your body make more insulin after you eat. That helps keep your blood sugar down after a meal. Semaglutide (Rybelsus) is the only form of this medicine that comes in pill form. The others are injectable. They are:

Side effects can include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Weight loss
  • Headache
  • Weakness
  • Dizziness

If pills aren’t enough to get your blood sugar under control, your doctor may recommend insulin. You take insulin as a shot. You can't take it like a pill because normal digestion would destroy it.

There are several different types, and they all work in different ways. Your doctor may recommend you use more than one.

Long-acting insulin reaches your bloodstream several hours after you inject it. It lowers your blood sugar over a 24-hour period. If you have type 2 diabetes, your doctor is most likely to have you take long-acting insulin at night.

Intermediate-acting insulin also begins to work several hours after you inject it, but it only works for about 12 to 18 hours.

Regular or “short-acting” insulin reaches your bloodstream about half an hour after you inject it. It does its job for 3 to 6 hours.

Rapid-acting insulin starts to work almost immediately after you inject it. It only works for 2 to 4 hours.

Low blood sugar (hypoglycemia) is a side effect of all forms of insulin. Doctors used to only prescribe insulin as a last resort for people with type 2 diabetes. Now, they often do it sooner because it lowers blood sugar.


Which type of treatment is best for you should always be a joint decision between you and your diabetes care team. Whichever they recommend, be sure to ask about the pros and cons of each medication, including:

  • What are side effects I should expect with each option?
  • How much do they cost?
  • How do I use them?
  • Where should I store them?

Also, be sure you understand how to tell if your blood sugar is too low, and what to do if it is.