Explaining active insulin

What is active insulin?

When insulin is delivered into your body, it doesn’t immediately disappear; it continues to work for a certain period of time, lowering your blood sugar levels. Active insulin refers to the amount of insulin that is still working in your body after you have given a dose of insulin.

Diabetes technology such as insulin pumps and smart insulin pens keep track of active insulin to ensure you aren’t giving another dose too close to your previous dose, which is also known as insulin stacking. This is an important safety feature to help avoid delivering too much insulin which could lead to low blood sugars.
 

Active insulin time

Active insulin time is how long the insulin is working to lower your glucose levels. The duration typically varies depending on the type of insulin used. For example, the rapid-acting insulin used in an insulin pump works for about 3-4 hours in most adults. Your healthcare team will personalize the active insulin time you program into your pump system based on a variety of factors, including age and historic glucose data.
 

Bolus Wizard™ feature

The Bolus Wizard™ active insulin time setting lets the pump know how long insulin continues to work in your body. It calculates the amount of active insulin and subtracts that amount before estimating a bolus. In other words, if the Bolus Wizard™ calculator recommends that you give a reduced amount of correction insulin or no correction insulin, it's because you have active insulin remaining from a previous bolus. This may help prevent hypoglycemia from overcorrecting for a high glucose level.
 

Active insulin time with SmartGuard™ technology

Did you know that active insulin time is different when using the SmartGuard™ feature (automated insulin delivery mode) on the MiniMed™ 780G system? When in SmartGuard™, active insulin time is used as a lever to strengthen automatic correction doses and doesn’t relate to how long the insulin lasts in the body. The recommended setting in SmartGuard™ technology is two hours. This allows the system to step in sooner to help correct high blood sugars. Don’t worry, the system is working behind the scenes to prevent stacking of insulin and will subtract insulin from your bolus doses if needed.

[Originally published 2013-10-14. Updated 2025-01-15]
 

Important safety information: MiniMed™ 780G system with SmartGuard™ technology with Guardian™ 4 sensor

The MiniMed™ 780G system is intended for continuous delivery of basal insulin at selectable rates, and the administration of insulin boluses at selectable amounts for the management of type 1 diabetes mellitus in persons seven years of age and older requiring insulin as well as for the continuous monitoring and trending of glucose levels in the fluid under the skin. The MiniMed™ 780G system includes SmartGuard™ technology, which can be programmed to automatically adjust insulin delivery based on the continuous glucose monitoring (CGM) sensor glucose values and can suspend delivery of insulin when the sensor glucose (SG) value falls below or is predicted to fall below predefined threshold values.

The Medtronic MiniMed™ 780G system consists of the following devices: MiniMed™ 780G insulin pump, the Guardian™ 4 transmitter, the Guardian™ 4 sensor, One-press serter, the Accu-Chek™ Guide Link blood glucose meter, and the Accu-Chek™ Guide test strips. The system requires a prescription from a healthcare professional.

The Guardian™ 4 sensor is intended for use with the MiniMed™ 780G system and the Guardian 4 transmitter to monitor glucose levels for the management of diabetes. The sensor is intended for single use and requires a prescription. The Guardian™ 4 sensor is indicated for up to seven days of continuous use.

The Guardian™ 4 sensor is not intended to be used directly to make therapy adjustments while the MiniMed™ 780G is operating in manual mode. All therapy adjustments in manual mode should be based on measurements obtained using a blood glucose meter and not on values provided by the Guardian™ 4 sensor. The Guardian™ 4 sensor has been studied and is approved for use in patients ages 7 years and older and in the arm insertion site only. Do not use the Guardian™ 4 sensor in the abdomen or other body sites including the buttocks, due to unknown or different performance that could result in hypoglycemia or hyperglycemia.
 

WARNING: Do not use the MiniMed™ 780G system until appropriate training has been received from a healthcare professional. Training is essential to ensure the safe use of the MiniMed™ 780G system.
 

WARNING: Do not use SG values to make treatment decisions, including delivering a bolus, while the pump is in Manual Mode. When the SmartGuard™ feature is active and you are no longer in Manual Mode, the pump uses an SG value, when available, to calculate a bolus amount. However, if your symptoms do not match the SG value, use a BG meter to confirm the SG value. Failure to confirm glucose levels when your symptoms do not match the SG value can result in the infusion of too much or too little insulin, which may cause hypoglycemia or hyperglycemia.
 

Pump therapy is not recommended for people whose vision or hearing does not allow for the recognition of pump signals, alerts, or alarms. The safety of the MiniMed™ 780G system has not been studied in pregnant women, persons with type 2 diabetes, or in persons using other anti-hyperglycemic therapies that do not include insulin. For complete details of the system, including product and important safety information such as indications, contraindications, warnings and precautions associated with system and its components, please consult https://www.medtronicdiabetes.com/important-safety-information#minimed-780g  and the appropriate user guide at https://www.medtronicdiabetes.com/download-library.