Hormone injections and their application

Administration via injections has a higher bioavailability (how much of the dose gets into the systemic circulation) compared to oral administration. Oral medicines are weakened by first-pass metabolism—they pass through your gastrointestinal tract and liver before taking any effects. Their bioavailability can sometimes be a few percent. Administration via injections has a bioavailability of almost 100%. This can be beneficial because: you'll absorb more of the substance, reduce the impact on the liver, using higher doses is possible and safe. If you're on Androcur (bad for the liver), have liver issues, or don't reach the desired levels of hormones, injections might be a better choice.

For trans feminine people, there are 2 products available—Neofollin (estradiol valerate) and Agofollin (estradiol benzoate, has not been available since 2020). Benzoate starts with a very high level of estrogen with a sharp decline. The high peak can cause severe mood swings. Valerate maintains more consistent levels for a longer period without such a high peak. Trans masculine people can use Sustanon or Nebido, we don't know the difference in their efficiency. However, Nebido is the only one of these products packed in a vial which is easier to use than ampules.

All of these products are applied intramuscularly. Subcutaneous variations (injecting into fat) exist, but they are not available in Czech Republic yet.

Injections can be applied by your general practitioner or at your sexology. If this is a viable variant for you, you don't need to worry about anything else. If you want to self administer the injections, it's necessary to prepare several things and learn the correct application. They'll likely show you how to apply the injection at the doctor's office, but you usually won't get all the information about the whole process.

First of all, you need to buy some material that helps with safe application. Don't forget anything on this list:

The following part can be uncomfortable for some people, we ask you to be cautious if you are afraid of needles or injections, especially if you tend to pass out.

First of all, prepare a safe space for the application of the injection. It's very important to be very relaxed, ask other people you live with to give you some space for a while. If you passed out at any point in the past or you don't feel well when receiving injections, it doesn't mean you can't use them as this can improve with time (otherwise, we don't recommend injections). In this case, we strongly recommend having someone to look after you. Even if you feel generally good about injections, it might be a good idea to get assistance for the first one. Let this person know what to do in case you pass out—we even recommend studying first aid for fainting. Always let the person know how you're feeling, if you feel sick, your head is spinning or you're seeing flashes, you are passing out. Always have the other person on the opposite side of the injection. If they know you're passing out, they shouldn't let you fall, they should ensure that you lie down easily and prevent you from falling towards the injection. It's best to pull out the injection, the tissue could get damaged more during spasms.

After ensuring safety, you should aspirate the substance. Prepare everything listed above. Aspiration might be different based on the product you're using.

Once the medicine is inside the syringe, it's important to remove all the air. If you're using a needle for aspiration, remove it and change it for the one you're going to apply the injection with. The aspiration needle is too thick and you would lose more of the substance. You remove the air by orienting the needle upwards and keep flicking the syringe. Once all the air gets upwards, push the plunger to get it out. Repeat this process until all the air bubbles are gone. Air injection during intramuscular injection is not so problematic, but it's best to avoid it. Now the syringe is ready for the application. If you want to put it aside, put the cover back on.

The choice of the injection site is mostly about preference, however, they will probably advise you where to self-inject at the sexology. For subcutaneous injections, you're likely gonna inject into the belly fat at a 45° angle. For intramuscular injections, we use a 90° angle and we can use several muscles. It's not recommended to inject into the shoulder or the dorsogluteal site (backside of the buttocks), although injections are common here, the site is less available and less safe. For self-injection, the ventrogluteal site (outer side of buttocks) and thigh (vastus lateralis muscle, which we'll describe here) is recommended. There are a lot of guides on how to find this site on the internet. Easy way to find the site: put a palm above the knee so that it covers the outer side of the thigh, do the same with the other hand, right under your crotch. Your palms should create a small imaginary window, which is the site for your injection. The injection shouldn't be applied at the top of the thigh but slightly on the side.

Once you find the site, disinfect it thoroughly, again, let the disinfectant evaporate, you can wipe it later as it might cause stinging during the injection. The last step is the injection.

You're probably fighting the stress and fear. 0.7 × 4 cm needle might look scary, but it's best to not think about it, it will essentially not hurt anyway. Once you're ready, put the needle close to the site, check if it's under 90°, make sure that your leg is relaxed, and swiftly insert the needle. It's not necessary to use a lot of strength, the needle is exceptionally sharp and will insert very easily. If you're inserting the needle slowly, it might cause more discomfort, however, it's not a big difference. In this case, don't freak out—once you hit the subcutaneous layer, the needle will pass through very quickly, then it will slow down again on hitting the muscle.

Once the needle is completely inserted, the worst part is done. It's recommended to aspirate inside of the muscle now. Hold the injection with one hand and pull the plunger. Aspirating might be difficult, but once you see bubbles enter the syringe, it means the needle is in the correct place. If you see blood enter the syringe (which means the injection is inside of a blood vessel where you can't inject the substance), it's necessary to repeat the process with a new needle. Considering the nature of the recommended injection sites, this problem will likely not occur.

After a successful aspiration, you can apply the medicine. Slowly push on the plunger, if you still see bubbles after the aspiration in your muscle, you don't have to worry about them. Once the substance is all applied, pull out the needle, disinfect the place once again and apply a medical patch.

Rarely, you might hit a nerve. It is an uncomfortable situation and might cause some pain, it's ideal to interrupt the injection, change the injection and try a different site. If this happens often, avoid this site.

Let the site rest after the injection, excessive strain could cause a hematoma. From a long-term point of view, it's recommended to switch the injection sites to let the site heal properly.