Do Injections Hurt?

by Gretchen Becker Patient Expert

One thing that always makes me wince is a news story about some new oral diabetes drug that the reporter says promises to free people with diabetes from “painful insulin injections.”

When I was a child, immunizations were painful. They were injected into a muscle, and after getting booster shots, my arm would ache for a day or two. The sight of the syringe with its big needle was frightening. The only good thing about getting immunizations was the treat we were given if we didn’t fuss. I remember being taken to the Elizabeth Taylor movie National Velvet, a big treat, as in those days we didn’t have TV and going to a movie was rare.

But most injections today are a totally different story. For one thing injections for diabetes, like insulin, are given subcutaneously, meaning they’re injected into the fat layer under the skin. And the needles used these days are extremely thin, so we hardly feel the shots at all.

One exception is the once-a-week injected exenatide, which requires larger needles than the twice-daily exenatide. This is because the way the action of the drug is extended is to encapsulate it into tiny spheres, and these spheres require larger needles.

With needles, larger numbers mean smaller needles. Most insulin and some of the GLP-1 drugs use 31 or 32-gauge needles. The extended release form uses 23-gauge needles, which are larger. So anyone with a real fear of needles might not like that version of the GLP-1 inhibitors.

The extended-release version can also cause nodules (little bumps) at the site of injection, although patients report that they fade with time.

The fingersticks we use to measure our blood glucose levels hurt more than the injections because we prick our fingertips, which are full of pain-sensitive nerves. But even though it’s very difficult to do the fingersticks at first, with practice we hardly feel them because we’re not focussed on the pricks.

The same is true of most insulin injections. Injecting ourselves becomes as routine as getting dressed in the morning. Not a big deal. And we give the shots in parts of the body that don’t contain a lot of pain receptors, so we hardly feel them. This is also true of some of the injected drugs used to control type 2 diabetes: the GLP-1 agonists, meaning drugs that increase the levels of glucagon-like peptide 1, as explained in a previous post.

An older insulin, ultralente, did sting a bit because the insulin was dissolved in an acidic solution that kept the individual insulin molecules separated. When the solution got into the interstitial fluid in the body, the insulin molecules clumped, and this allowed them to release slowly. Unfortunately, UL insulin, which was a lot cheaper than today’s long-lasting insulins, is no longer available.

There are drawbacks to using any injected drug. Although this is rare, there’s always the possibility of an allergic reaction at the injection site, or even an infection. Traveling with injected drugs is more complex as you have to keep any liquids in clear plastic bags you can show to the security personnel. And drugs like insulin should be kept cool.

However, when you and your physician discuss whether or not it makes sense for you to go on an injected drug, “painful shots” need not be part of the discussion.

Gretchen Becker
Meet Our Writer
Gretchen Becker

Gretchen wrote for HealthCentral as a patient expert for Diabetes.