Drug Facts: Basal Insulin
Updated: Oct 25
Not all insulins are created equally! There are several different kinds and strengths as well as different ways they can be taken.
Insulin is typically categorized as either basal or bolus. Basal insulin is a "background" insulin, which controls blood sugars all day long, particularly between meals and while you are sleeping.
Basal insulin is frequently the first insulin prescribed to people with type 2 diabetes. Most people take it once daily, so there is no need to worry about taking it with you to restaurants or dinner parties. However, you will obviously need to bring it with you if you are staying somewhere overnight. Some people take it first thing in the morning, while others take it before bed. Everyone’s dose is different as it is based on how much you weigh, as well as your insulin resistance. Your provider may start you on a small dose and then “titrate” it to a dose that’s suited for you. Your dose may go up or down as over time as well.
Long-acting insulin is the most common type of basal insulin. Levemir and Lantus have been on the market for some time now, and Basaglar became available in 2016. They last for about 24 hours, so it’s important to take it at roughly the same time every day.
Ultra-long-acting insulin is a newer type of basal insulin, with Toujeo coming to the US in 2015 and Tresiba in 2016. They last longer than 24 hours (36 and 42+ hours respectively) so the time of day you take it isn’t as important compared to long-acting insulins. There seems to be less hypoglycemia with these newer insulins as well. Another benefit is that they are more concentrated, meaning that a larger dose can be taken at one time, and more units are in a pen. This is helpful for people that take large doses of the medication. Unfortunately, these ultra-long-acting insulins are generally more expensive in comparison to their long-acting counterparts.
Intermediate-acting insulins can be used as a basal insulin as well. These are not preferred as they can make blood sugars more erratic, with a higher risk of hypoglycemia. If you are struggling to pay for your insulin though, this may be an option due to the lower cost. Always weigh the pros and cons of the various medication options with your provider to decide which is best for you. If you are taking this type of insulin, be sure that you’re mixing it thoroughly by rolling the pen in your hands or inverting the vial – be sure to read the package insert for the full instructions!
With basal insulin you really don’t have to worry about your blood sugars dropping rapidly as it works in a slow and steady fashion (with the exception of intermediate-acting insulins). There is however some risk that basal insulin can cause hypoglycemia, especially if you are exercising more than normal or eating less than usual. If you are having hypoglycemia frequently, talk to your provider as your dose may need to be decreased.
Basal insulin can be used in combination with bolus insulin, as well as oral or other injectable medications. Potential side effects for all insulins include weight gain and hypoglycemia.