What Diabetic Medications Do

Diabetic medications work in different ways to bring your blood sugar down or keep it steady. Some help your pancreas make more insulin. Others help your body use the insulin it already makes. Still others slow digestion so sugar enters your bloodstream more slowly. Your doctor picks which medication fits your situation based on your blood sugar numbers, your other health conditions, and how your body responds to treatment.

Most people with type 2 diabetes start with one medication and may add others over time as their body changes. Type 1 diabetes always requires insulin because the pancreas cannot make it. The goal is the same either way: keep your blood sugar in a range that protects your heart, kidneys, eyes, and feet from damage.

Key Takeaways

  • Metformin is usually the first medication doctors prescribe for type 2 diabetes because it lowers blood sugar and rarely causes dangerously low blood sugar on its own.
  • Insulin comes in different types that work at different speeds, and type 1 diabetes always requires it while type 2 may need it later.
  • Newer medications like GLP-1 drugs can lower blood sugar, help you lose weight, and protect your heart, but they cost more and may not be covered by all insurance plans.
  • Side effects and cost matter — tell your doctor if a medication makes you feel sick or if you cannot afford it, because other options usually exist.
  • Blood sugar checks at home help you and your doctor see whether your current medication is working or needs to change.

Metformin and Other First-Line Medications

Metformin is the medication most doctors start with for type 2 diabetes. It lowers blood sugar by helping your liver and muscles use glucose better and by slowing how fast your stomach empties food. Metformin rarely causes your blood sugar to drop too low on its own, which makes it safer than some other drugs. It comes as a tablet or liquid, usually taken once or twice a day with meals.

Common side effects are stomach upset, nausea, and diarrhea, especially when you first start it or when the dose goes up. These often fade after a few weeks. Taking metformin with food helps. If your kidneys do not work well, your doctor may lower the dose or choose a different medication instead, because metformin can build up in your body and cause harm.

If metformin alone does not bring your blood sugar down enough after a few months, your doctor will add a second medication rather than stop metformin. Metformin protects your heart and may help you lose weight, so doctors usually keep it even when adding other drugs.

Insulin and How It Works

Insulin is a hormone that moves glucose from your blood into your cells. People with type 1 diabetes must take insulin because their pancreas stopped making it. People with type 2 diabetes may need insulin later if other medications are not enough. Insulin comes as an injection under the skin, a pen, or a pump that delivers it continuously.

Different types of insulin work at different speeds. Rapid-acting insulin (like Humalog or NovoLog) starts working in 10 to 15 minutes and peaks in an hour — you take it right before meals. Long-acting insulin (like Lantus or Levemir) works slowly over 24 hours and keeps your blood sugar steady between meals and overnight. Many people take both types: long-acting once or twice a day, plus rapid-acting before meals. Your doctor will tell you which types and how much to inject.

Low blood sugar (hypoglycemia) is the main risk with insulin. Symptoms are shakiness, sweating, fast heartbeat, confusion, and hunger. Always carry fast-acting sugar — juice, glucose tablets, or candy — and tell people around you what to do if you cannot treat it yourself. Your doctor or a diabetes educator will teach you how to inject, how much to take, and when to adjust your dose based on your blood sugar readings.

Newer Medications That Lower Blood Sugar and Protect Your Heart

GLP-1 receptor agonists (such as Ozempic, Victoza, Trulicity, and Mounjaro) are newer drugs that work by making your pancreas release more insulin when blood sugar is high and by slowing digestion. They also help many people lose weight and lower the risk of heart attack and stroke. These medications come as a weekly injection or a daily injection, depending on which one your doctor prescribes.

Side effects often include nausea, especially at first, and sometimes vomiting or constipation. These usually improve after a few weeks. A rare but serious side effect is pancreatitis (inflammation of the pancreas), which causes severe belly pain. Stop the medication and call your doctor right away if that happens. These drugs are more expensive than metformin and insulin, and not all insurance plans cover them without a prior authorization from your doctor.

SGLT2 inhibitors (such as Jardiance, Invokana, and Farxiga) work by making your kidneys remove more glucose through urine. They also lower blood pressure and protect your heart and kidneys. You take them as a daily tablet. Side effects can include yeast infections and urinary tract infections because glucose in urine feeds bacteria. Drink plenty of water and watch for signs of infection.

Other Medications That Add to Your Treatment Plan

Sulfonylureas (such as glipizide and glyburide) make your pancreas release more insulin. They work quickly but can cause low blood sugar, especially if you skip meals or exercise more than usual. Doctors use them less often now because newer medications are safer.

DPP-4 inhibitors (such as sitagliptin and linagliptin) help your pancreas release insulin when blood sugar is high and do not usually cause low blood sugar on their own. You take them as a daily tablet. They are gentler than sulfonylureas but do not lower blood sugar as much as some other drugs.

Thiazolidinediones (such as pioglitazone) help your body use insulin better. They can cause weight gain and fluid buildup, so your doctor will monitor you closely. They are used less often now because of these side effects.

Managing Side Effects and Cost

Every medication can cause side effects. Some fade after your body adjusts; others do not. Nausea, diarrhea, dizziness, and weight changes are common. Tell your doctor about any side effect that bothers you or changes how you live. Do not stop taking a medication on your own — your doctor can lower the dose, switch you to a different drug, or add something to ease the side effect.

Cost is real. Insulin and newer medications can be expensive even with insurance. If you cannot afford your medication, tell your doctor before you skip doses or stop taking it. Many drug makers offer patient information programs that lower the cost or provide the medication free if your income is below a certain level. Your doctor's office or a social worker can help you find these programs. Some states also have programs that help seniors pay for medications.

Generic versions of older medications like metformin and some insulins cost much less than brand-name drugs and work the same way. Ask your doctor or pharmacist whether a generic is available for what you are taking.

Checking Your Blood Sugar to Know If Your Medication Is Working

Blood sugar checks at home tell you and your doctor whether your current medication is doing its job. You prick your finger, put a drop of blood on a test strip, and a meter shows your number. Your doctor will tell you what range to aim for — usually 80 to 130 before meals and under 180 two hours after meals, though this varies by person.

Write down your readings or use an app so you can see patterns. If your numbers are often too high or too low, bring your log to your next visit. Your doctor may adjust your dose, change the timing of when you take it, or add a different medication. Some people use a continuous glucose monitor (CGM) that checks blood sugar every few minutes and alerts you if it gets too high or too low — ask your doctor whether this might help you.

Questions to Ask Your Doctor About Your Medication

Before you start a new medication, ask your doctor these questions: What does this drug do? How will I know if it is working? When should I take it — with food, on an empty stomach, at a certain time of day? What side effects might happen, and which ones mean I should call you? What should I do if I forget a dose? How much will it cost, and does my insurance cover it? Are there programs that can help me pay for it?

Also ask: Can I take this with my other medications, or will it interact with them? What should I do if I get sick or have surgery? If this medication is not working after a few months, what is the next step? Your doctor or a diabetes educator should take time to answer these questions and make sure you understand how to take your medication safely.

Frequently Asked Questions

Can I stop taking my diabetes medication if my blood sugar is normal?

No. Your medication is keeping your blood sugar normal. If you stop, your blood sugar will likely go back up. Talk to your doctor before making any changes. Sometimes your doctor may lower your dose if your weight, exercise, or diet changes a lot, but stopping suddenly can be dangerous.

What should I do if I cannot afford my medication?

Tell your doctor right away. Many drug makers offer free or low-cost medications through patient information programs based on your income. Your doctor's office, a social worker, or a 211 call can connect you to these programs. Generic versions of many older medications cost much less. Do not skip doses to save money — that puts your health at risk.

Is it normal to take more than one diabetes medication?

Yes. Most people with diabetes eventually take two or more medications because one drug alone is not enough to keep blood sugar in a healthy range. Your doctor will add medications slowly and watch how you respond. Taking multiple medications is normal and safe when your doctor prescribes them.

What is the difference between type 1 and type 2 diabetes medications?

Type 1 diabetes always requires insulin because the pancreas cannot make it. Type 2 diabetes usually starts with pills like metformin that help your body use insulin better, and insulin is added later if needed. Some newer medications work for both types, but the starting point is different.

What should I do if I have side effects from my medication?

Call your doctor and describe what you are feeling. Do not stop taking the medication on your own. Your doctor can lower the dose, switch you to a different drug, add something to ease the side effect, or wait a few weeks to see if it improves. Some side effects fade as your body adjusts.