If you have diabetes, taking medicines is a major part of staying healthy because they help keep your blood sugar levels under control. Having blood sugar that's out of control can make you feel awful and can damage your body over the years.

Whether you have type 1 or type 2 diabetes, it's important to know what medicine to take, when to take it, and how much to take.

What Is Insulin?

What Happens in Diabetes?

Insulin is a hormone that lets sugar, or glucose, get into the body's cells where it can be used for energy. All people with type 1 diabetes and many people with type 2 diabetes need to take insulin every day.

The overall goal of treatment with insulin (and other diabetes medicines) is to match the amount of insulin given with the amount of insulin a person needs throughout the day and night. Doing this means that blood sugar levels can be kept as close to normal as possible, which helps a person avoid both short- and long-term problems from diabetes.

The types of insulin you use and how much you need to take each day depends on your diabetes management plan. Some people with diabetes need to take two injections each day. Others may need several injections or an insulin pump to keep blood sugar levels under control. Your doctor will help you decide what's best for you.

There are a few different kinds of insulin. They differ from one another based on:

  • how long they take to start working
  • when they work their hardest to lower blood sugar
  • how long they last

The table below outlines the types of insulin and how they work. The time it takes for insulin to work, when it peaks, and how long it lasts is different from person to person, and even from day to day as the way a person's body reacts to insulin may change. After a while, you'll get to know how insulin works in your body.

Rapid-Acting Insulin

When It Starts Working: 10–15 minutes
When It Works Hardest: 30–90 minutes
How Long It Lasts: 4 hours
How It Works: Used to help your body handle glucose that you absorb when eating a meal. For the best results, it is usually taken several minutes before or just before eating. Looks clear and can be mixed with intermediate-acting insulin in the same syringe.

Short-Acting Insulin

When It Starts Working: 30–60 minutes
When It Works Hardest:  2–4 hours
How Long It Lasts: 6–9 hours
How It Works: Used to help your body handle glucose that you absorb when eating a meal, but lasts longer than rapid-acting insulin. Take it 30 minutes before eating. Looks clear and can be mixed with intermediate-acting insulin in the same syringe.

Intermediate-Acting Insulin

When It Starts Working: 1–4 hours
When It Works Hardest:  3–14 hours
How Long It Lasts: 10–24 hours
How It Works: Works to control glucose between meals and during the night. Looks cloudy or and can be mixed with rapid- and short-acting insulin in same syringe.

Long-Acting Insulin

When It Starts Working: 1–2 hours
When It Works Hardest:  does not peak
How Long It Lasts: 18–24 hours
How It Works: Works to control glucose between meals and during the night. Looks cloudy or clear and can't be mixed with other insulin in the same syringe.

The Importance of Timing

You can't "turn off" insulin once it's been injected — it's going to work no matter what — so you have to make sure you're using the right amount at the right time. For example, if you'll be eating later than usual because you're eating out, you might need to hold off on your insulin injection, eat a small snack at your normal mealtime, and take the insulin later.

Sticking to a meal plan from day to day and getting regular physical activity — in addition to taking your meds — will help you keep your blood sugar levels in a healthy range and will make it easier to know how much insulin to take. If you run into situations where you're not sure how to adjust your insulin dosage to account for food or exercise, ask a parent or a member of your diabetes health care team.

Although you may do everything you're supposed to, sometimes blood sugar is hard to control. For people with diabetes, there will be times when the amount of insulin they have taken will be too much or too little for the body's needs and the blood sugar level will be too high or too low.

A common problem among people who take insulin is low blood sugar, or hypoglycemia. It can happen at any time, but is more likely if someone eats less or exercises more than usual. Hypoglycemia is also more likely in the first few weeks or months after a person develops type 1 diabetes.

If your blood sugar goes too low regularly, it may mean that your insulin dose or meal plan needs adjusting. If this happens, contact your diabetes health care team. They'll help you develop a plan to help keep your blood sugar levels as close to normal as possible.

Tips for Using Insulin

Insulin can't be taken as a pill because the acids and digestive juices in the stomach and intestines would destroy it before it could do its job. The only way to get insulin into the body at present is by injection with a needle or with an insulin pump.

Before giving yourself an insulin injection, always check the bottle to make sure you're using the right type of insulin and that it hasn't expired. You should also inspect the bottle to see if the insulin looks OK — for example, it should not have particles or crystals floating in it. If you have any questions about whether the insulin is OK to use, ask a parent or your doctor about it.

Here are some guidelines on storing bottled insulin (check manufacturer's instructions for storage of insulin pens):

  • Keep unopened bottles of insulin in the refrigerator. Throw away insulin if it has been frozen or is past the expiration date on the bottle.
  • Opened bottles of insulin can be stored in the refrigerator or kept at room temperature.
  • Avoid leaving insulin in direct sunlight or in a car on a sunny or hot day because it can become overheated. If you're going to be traveling or outdoors, store insulin as you would perishable food (but do not freeze it).
  • Depending on the type of insulin, opened bottles should be thrown away after 4 to 6 weeks (check manufacturer's instructions), whether they have been kept refrigerated or not.
  • Never use any insulin that has expired.

Diabetes Pills

Many people with type 2 diabetes take diabetes pills — in addition to eating right and exercising — to get their blood sugar levels into a healthy range. Sometimes doctors call these pills oral medicines because you put them in your mouth and swallow them.

People with type 2 diabetes have trouble using the insulin their bodies make properly, so some diabetes pills help them use insulin more effectively. (In some cases, though, they might need to take insulin too.) Other kinds of diabetes pills may help the person's body make more of its own insulin. Diabetes pills help reduce the amount of glucose that appears in the bloodstream between meals and at night. They may also help some people with type 2 diabetes lose weight and help improve cholesterol and triglyceride levels.

Taking diabetes pills can help keep blood sugar levels under control, but sometimes it can cause side effects such as a funny taste in your mouth, nausea or vomiting, and diarrhea. Often these symptoms go away or get a lot better after taking diabetes pills for a few weeks.

Your doctor may tell you to stop taking diabetes pills when you are sick with something like the flu. Drinking alcohol when taking diabetes pills also can make some people sick, so it's important not to drink when you're taking these.

If you have any problems or feel sick after taking diabetes pills, talk to your doctor or your diabetes health care team.


Insulin and other diabetes medicines help to keep blood sugar levels from going too high or too low. But sometimes people with diabetes get really low blood sugar, or hypoglycemia, that can make them become confused, have seizures, or pass out if it's not treated right away.

A person who has really low blood sugar probably needs a glucagon shot. Glucagon (pronounced: GLOO-kuh-gon) is a hormone that helps raise blood sugar levels very quickly (in about 10 to 15 minutes after the shot).

The adults in your life — like your parents, teachers, and coaches — should know how and when to give glucagon shots (you wouldn't be able to do this yourself) or when to call 911 because of a diabetes emergency. You should also always wear a medical identification bracelet so that health care personnel and others know that you have diabetes in case of an emergency in which you might have to depend on people who don't know you for help.

Getting a grip on your diabetes medicines — when to take them, how much to take, and when to ask for help — can make managing your diabetes easier. If you have any questions about diabetes medicines, talk to your doctor or anyone on your diabetes health care team.

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