Injections
✅ Injections are a very efficient and safe route, on long term as well, leading to relatively stable and high levels of estradiol. It is safe as long as you perform the injection well, and make sure that the product you use if legit and uncontaminated. The main problem is that their are not available in most european countries, and necessitates DIY competences.
| Products | Doses | Blood values to monitor |
|---|---|---|
| None available through prescription in Sweden | Estradiol Valerate : 4 to 7 mg every 5 days / Estradiol Cypionate : 6-7 mg every 7 days or 10-11 mg every 10 days / Estradiol Enanthate : 7.5mg every 7 days or 10-15 mg every 14 days | Estradiol, Testosterone, FSH/LH, SHBG |
Injections of estrogens are not very common in Europe. It is, however, a much more common administration route in other countries, namely in the USA, Latin America, and Japan.
Injection - if you don’t have issues with needles - is a very convenient way to reach high levels of estradiol for monotherapy. It allows for longer time between intakes (up to 15 days with estradiol enanthate). It is also relatively cheap as a vial bought on the grey market costs between 55 and 75 $ USD and can usually last for a year (between 4.5 and 6.5 $/month).
Injections are typically performed as Intramuscular or Subcutaneous. It works by leaving a depot (a small reserve) in the muscle or fat tissue. The depot will slowly release the products, which will enter the bloodstream gradually.
We give more detail on the dedicated pages on how to perform those two types of injections.
What is good to know here is this:
- Intramuscular injection means injection inside the muscle tissue. It usually means using a longer needle, which can be a bit more painful and more uncomfortable if you don’t like needles. The muscle tissues being more vascularized, absorption is faster.
- Subcutaneous injections means injecting between the skin and the muscle, in the fat layer. We usually choose a spot with more fat (upper butt…). With less blood vessels, absorption of the depot in fat tissue is slower, which allows for even longer time between injections, and more gradual increase of the levels after injections.
Esters – What are they?
Injections come with slightly different molecules, which will have a consequence on absorption speed and levels of estradiol reached per shot (and hence, the frequency and doses of each injection). What we use for estrogen injections is called an ester.
An ester designates a molecule (here estradiol) that has been esterified; meaning it has been slightly modified by an addition/replacement of a chain of atoms. This technique is used in many medications, in the objective of optimizing the bioavailability of the drug (and how efficient it is in our system). In a way, the idea is to anticipate the fact that after intake, the body will metabolize the molecule into a weaker (or just very different) form. Esterification creates what we call a “prodrug”: an inactive drug taken as such, but that will become active after its metabolization by the body.
Imagine you want to take a molecule we simplify as “AB”. If you take it just like that, the body will metabolize AB into A, and it won’t be exactly what you want. Esterification consists in first turning AB into ABC; then, after ingestion or injection, the body will then metabolize ABC into AB, and you’ll end up with what you want. For this reason (because estradiol esters are metabolized into estradiol), estradiol esters are considered bioidentical estrogens and not synthetic. The active molecule acting on your body remains, at the end, estradiol (E2).
The main esters used for injections are, Estradiol valerate, Estradiol enanthate and Estradiol cypionate.
Estradiol valerate usually leads to a fast and high peak, falling down rather quickly as well. It means more frequent injections, and also a bigger span between high and low (unstable levels)- which can affect your mood. (Note that estradiol valerate is also used for the oral pill Progynon)
Estradiol enanthate gives slightly lower levels (though still high compared to other routes), but lasts longer. This allows for more stable levels, and the possibility to space out injections (once a week for best stability, up to once every two weeks).
Estradiol cypionate behaves similarly with again slightly lower levels.
You can refer to this Injectable Estradiol Simulator, but keep in mind that data is sometimes scarce, and your actual levels can vary greatly. The best remains to check your levels with blood work, and listen to your body and mind.
Pros
- Easily gives high levels of estrogens
- Allows for easy monotherapy and hence avoid androgen blockers
- Lower risks than with oral route
- No difference of absorption between individual (everyone is receptive)
Cons
- Can produce unstable levels (but can be corrected by dose/frequency adjustments)
- Impossible to get through the legal/prescription market.
- It’s an injection (needle fear…)
Please refer to the dedicated page for details about practicing safe injections.