Taking insulin is often an important part of diabetes treatment
If you have Type 1 diabetes, your doctor prescribes insulin to replace the insulin your body is unable to produce.
Insulin is sometimes prescribed for persons with Type 2 diabetes when diabetes pills and lifestyle changes failed to control blood glucose levels. It is also prescribed in
gestational diabetes when diet alone is unable to control blood glucose1.
Understanding how insulin works can help you better manage your condition and prevent serious problems.
Insulin controls blood glucose in two ways:
In Type 1 diabetes, the body produces little or no insulin. For Type 2 diabetes, the body does not produce enough insulin or the insulin is not working properly. In both cases, the absence or ineffectiveness of insulin causes blood glucose levels to spike. Prolonged high blood glucose can lead to serious problems like blindness, nerve damage and kidney failure.
There are many types of insulin. Some work slowly and some quickly.
This table explains the different types of insulin. Depending on your condition and lifestyle, your doctor will decide which types of insulin you need and how much you should take each time. Remember to follow your doctor’s instructions closely so that insulin treatment works for you.
Type of Insulin
Common Insulin Names
When to Take it
How Soon It Starts to Work
How Long Does It Last
Right before a meal
30 minutes before a meal
Before breakfast and/or at bedtime
Daily at the same time (e.g. bedtime)
Premixed mixture of rapid-acting and medium-acting insulin
Humalog Mix 25/75
Right before breakfast and/or right before the evening meal
Premixed mixture of short-acting and medium-acting insulin
30 minutes before breakfast and/or before the evening meal
Source: Ministry of Health Singapore (2014). Diabetes MOH Clinical Practice Guidelines 1/2014.
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This article was last reviewed on
18 Aug 2023
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