It peaks 30 to 90 minutes later and may last as long as 5 hours. It peaks 2 to 4 hours later and stays in the blood for about 4 to 8 hours. They peak 4 to 14 hours later and stay in the blood for about 14 to 20 hours. It has no peak or a very small peak 10 to 16 hours after injection. It stays in the blood between 20 and 24 hours.
Some insulins come mixed together.
For example, you can buy regular and NPH insulins already mixed in one bottle. They make it easier to inject two kinds of insulin at the same time. However, you can't adjust the amount of one insulin without also changing how much you get of the other insulin. Insulins come dissolved in liquids at different strengths. Most people use U-100 insulin.