There are different ways to administer medicines or vitamins into the body. Injections are dosage forms that deliver a substance into the bloodstream with better bioavailability, or a faster absorption rate. A common method of injection used by healthcare professionals is a subcutaneous injection. Vitamin B12 shots can also be administered at home in the form of a subcutaneous injection. 

The term subcutaneous means under the skin. This type of injection uses a short needle to inject the contents of a vial into the tissue layer between your skin and muscle. However, compared to other methods like intramuscular and intravenous injections, subcutaneous injections may be absorbed more slowly into the bloodstream. So what does it offer?


The Purpose of a Subcutaneous Injection  

A subcutaneous injection is often used for medications absorbed slowly and steadily into the bloodstream. This is because there are fewer blood vessels in the fatty tissues beneath our skin. Subcutaneous injections can often be injected at home depending on the medication injected. A subcutaneous injection is often the preferred method of administration for vitamin B12 and similar supplements

A subcutaneous injection is used by healthcare professionals when other methods of administration are less efficient. Oral medications can be at the mercy of the digestive system, and the absorption of oral medications may be hindered by other drugs or medical conditions. Intravenous and intramuscular injections can be difficult and more painful to administer than a subcutaneous injection. 

Subcutaneous injections are perfect for certain doses of delicate drugs. It can be a safe, convenient, and comfortable method of administration.      

People prefer subcutaneous injection when administering small amounts of medicines or vitamins, such as vitamin B12, at home. This method is suitable for people who are anxious about needle injections. However, this only applies if your medicine is appropriate for subcutaneous administration.  


Location of Injection Sites

With subcutaneous injections, drugs are delivered into the fatty tissue underneath your skin. Hence, some areas of your body may seem more convenient. The needle should easily be inserted into the fatty layer without hitting any muscles, bone, or blood vessels.

The abdomen, arm, and thigh are the most common sites for subcutaneous injection. These parts of our body have more fatty tissues.  


If you need to take a drug through subcutaneous injection often, you may need to rotate the injection sites. Using the same injection site twice in a row or multiple times can cause discomfort or damage to the skin. 

Like with any injection method, you should keep the site of the injection clean. Keeping everything sanitized will help prevent infection.  

This method of injection is only applicable for administering a small dose of drugs. 

Additionally, the absorption rate of subcutaneous injection is slower compared to intramuscular and intravenous. 


How to Administer a Subcutaneous Injection

It is helpful to be informed of the process of administering a subcutaneous injection. It may also help with the anxiety of taking the injection. Additionally, if you plan to self-administer at home, you will need to be knowledgeable on how to deliver your medicine or supplements subcutaneously.

There are some supplies needed for subcutaneous injection. The type of syringe used will differ from other types of injection. Your healthcare provider will help you determine the appropriate needle size and gauge. 

The medication will come in a liquid solution contained in a vial. The site of injection should be sanitized with an alcohol pad or cotton ball prior to injecting the solution.   

After choosing the location of the injection site, the syringe will be prepared to contain the medicine. Then, the medication will be injected into the fatty tissue. The angle of the needle and the way the syringe will be inserted will depend on a few factors. Contact your healthcare provider for more information on how to use the syringe. 


Subcutaneous injection is a method of administering medication into the fatty tissues. It does not bypass the stomach and absorbs faster than oral intake of medicines. However, it absorbs slower than intramuscular and intravenous methods. Still, this method of injection may be more suitable for drugs and vitamins to be slowly absorbed over time. 

Your healthcare provider can assess your condition and demonstrate to you the best way to administer the injection. If you’re needing more information on subcutaneous injections, especially if you’re administering a vitamin B12 shot at home, you can contact the team at Medical Weight Loss Centers of America. The experts at MWLCOA are here to help guide you on your journey to a healthier you.