If you take insulin, chances are, you use a strength of insulin called U-100 insulin (strength is not the same thing as type). U-100 insulin is the most common strength of insulin in the US. The U-100 means that there are 100 units of insulin per milliliter of liquid. If you’ve traveled abroad, you may have used or seen another strength of insulin called U-40 insulin. As the name implies, this insulin has 40 units of insulin per milliliter of liquid. U-40 insulin is not used in this country. And there’s yet another strength of insulin, U-500, that is used in cases of insulin resistance.
Before we discuss U-500 insulin, let’s back up for a moment and address the issue of insulin resistance. It’s a popular term that’s thrown around a lot lately, and chances are, if you have it, you know it. But in case you need a refresher, here’s what it means: Insulin resistance occurs when your body makes insulin (or otherwise has enough available) but can’t use it effectively.
As a result, glucose levels climb higher and higher in the bloodstream simply because the insulin isn’t doing its job of allowing glucose to enter cells to be used for energy. The beta cells in the pancreas struggle to keep up with the insulin demand and begin to work overtime, but eventually, they burn out and stop making enough. There’s only so much these cells can do. If someone does not yet have diabetes, but they have insulin resistance, it’s not hard to figure out where this leads: Type 2 diabetes. But it can also occur in people who already have diabetes.
There are many factors that can lead to insulin resistance, including excess body weight, lack of physical activity, ethnicity, hormones, certain medications, smoking, and lack of sleep. Of course, it’s helpful to tackle the cause of insulin resistance, and health-care providers may prescribe a number of approaches, including weight loss, exercise programs, a change in medication, quitting smoking, and getting enough sleep.
People who have Type 1 diabetes must take insulin in order to survive. There are no other treatment options. People who have Type 2 diabetes may be able, at least initially, to manage their diabetes through weight control, healthy eating, and physical activity. Eventually, many people with Type 2 must take medicine, typically starting off with metformin. Over time, other medicines may be added from different classes of drugs. Ultimately, the majority of people with Type 2 will need to take insulin. This is not a bad thing. It’s just that the beta cells that make insulin get tuckered out and can’t keep up with the body’s demand for insulin, especially if insulin resistance is present.
Sometimes people (with either Type 1 or Type 2 diabetes) who take insulin are faced with what seems like higher and higher doses of insulin. They may be injecting 100 units or more of U-100 insulin every day. Some of the downfalls of taking so much insulin are:
• Having to take several injections each day due to the large volume
• Decreased absorption due to the large amount of insulin
• Pain at the injection site
• Cost for insulin and syringes or pens and needles
One way to address these drawbacks is by using U-500 insulin. U-500 insulin is insulin that is five times more concentrated than U-100 insulin. It has a “peak” like regular insulin but a duration more like NPH insulin. It’s taken about 30 minutes before a meal. So, it works like both basal and bolus insulin, providing coverage for food while also providing coverage for overnight and between meals.
What to know
Here is more information about U-500 insulin:
• It starts to work about 30 minutes after you inject it.
• It peaks, or works its hardest, anywhere from 1 3/4 to 4 hours after injection.
• It lasts roughly for 6–10 hours, and maybe longer in some people.
• There’s a risk for low blood glucose 18–24 hours after the injection.
Why would you want to switch? You end up taking less U-500 insulin, for one thing. For example, if you were taking 100 units of U-100 insulin every day, you’d now be taking just 20 units of U-500 insulin. Plus, the other potential issues of injection site pain and decreased absorption would likely no longer be issues. Other benefits include fewer daily injections, only taking one type of insulin, and even better, you might notice more of an A1C drop than you would with U-100 insulin.
Some things to think about before you switch:
• U-500 does not come in a pen, so you must use a syringe to inject it.
• There are no U-500 syringes; you need to use a U-100 syringe or a TB syringe.
• As mentioned earlier, there’s a risk for low blood glucose hours later.
• Weight gain is likely.
• Because of its strength, it’s important that you receive education from your health-care provider or diabetes educator on how to use U-500, especially around dosing and drawing up into a syringe.
• Pharmacies do not always have U-500 insulin in stock, so it may take several days for them to order it.
U-500 insulin is made by Eli Lilly. You should make sure that this insulin is covered by your health-care plan. If you think U-500 might be right for you, talk to your provider.