Why did the "butt injection" that was popular when we were young disappear?

Hello, this is Science Popularization China. When it comes to injections, do you think of "injections in the buttocks" or "injections in the arm"? If you are a little older, you probably think of an injection in the buttocks. But now it seems that injections in the buttocks are rarely seen. Why is that?

Image source: unsplash.com Photographer: Mufid Majnun

To explain this question, we must first understand what a butt injection is. This is actually a type of intramuscular injection, which means injecting the drug directly into the muscle tissue. In addition to intramuscular injection, we also commonly use intravenous injection, subcutaneous injection and intradermal injection, which are suitable for different types of scenarios.

The characteristic of intramuscular injection is that it can prevent drugs from being metabolized by the liver, allowing the drugs to take effect more slowly. This injection method is often used when injecting many vaccines and drugs that are more irritating to blood vessels. The muscles on the buttocks are very "thick", so of course they have become "excellent candidate areas" for intramuscular injection. In addition, the outer thighs and the deltoid muscles on the arms are also very suitable areas for intramuscular injection.

Image source: unsplash.com Photographer: Steven Cornfield

But why does a butt shot hurt so much? This may be related to the psychological fear of injections when you were a child, as well as the low tolerance for pain. In addition, when medical conditions were not well developed, many hospitals and clinics did not use disposable needles, but sterilized and reused needles. After repeated use, these needles inevitably have some "small burrs", and it is really painful when such needles pierce the flesh.

After the improvement of medical conditions, although there are no blunt needles anymore, in order to avoid the thick fat layer on the buttocks, buttocks needles are often inserted very deep. The deep wound caused by the needle will also increase the pain.

There is another reason that not many people know. In the past, when giving buttock injections, medical staff would perform aspiration before injection to ensure that the needle did not pierce the blood vessels. A 2015 review pointed out that this operation causes more pain. So this may be one of the reasons why we felt that buttock injections were "painful" when we were young.

Image source: unsplash.com Photographer: Diana Polekhina

But why do butt shots seem to have disappeared now? In fact, butt shots have not disappeared, but the scenarios where this injection method is needed have become less frequent. The most important reason is that with the development of modern medicine, there are more drugs that can be taken orally than before. If something can be solved with medicine, there is certainly no need to get another shot. For adults, some vaccines that do not require a particularly large dose can also be completed with an arm shot. Moreover, if the butt shot is not injected properly, it may also cause sciatic nerve damage.

Because of these reasons, buttock injections are becoming less and less popular. That's all for today, see you next time.

Reviewer: Tang Qin, Director and Researcher of the Science Popularization Department of the Chinese Medical Association