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Estradiol Enanthate, a Long-Acting Injectable Estradiol Ester, is Being Sold Online by Transfeminine Homebrewers

By Aly W. | First published February 24, 2019 | Last modified March 6, 2021

Notice: This page was originally posted as a thread on Reddit and has not yet been properly or fully revised since being moved to Transfeminine Science.

Lena is a transgender woman living in Ukraine who has made and sold cheap homebrewed injectable estradiol valerate (EV) for do-it-yourself (DIY) transfeminine people since late 2017. She ships her products worldwide from her country. Lena’s site can be found at http://lena.kiev.ua/EV/.

Lena started offering estradiol enanthate (EEn or E2-EN) in early 2019. EEn is a long-acting injectable estradiol ester that has been used widely in in combination with the progestin algestone acetophenide (dihydroxyprogesterone acetophenide; DHPA) in once-a-month combined injectable contraceptives (CICs) in Spain and Latin America. She provides EEn by itself as follows: “ready-to-use solution of estradiol enanthate 500 mg/vial (10 ml/vial 50 mg/ml) in ethyl oleate [oil].” EEn is notable in that it is the longest-acting parenteral estradiol ester that remains pharmaceutically available. In addition, pharmaceutical EEn has limited availability and is not available for use by itself. It also does not seem to be available for purchase from any online pharmacies.

Beginning in 2020, homebrewed EEn has also been sold by Lilian of “Otokonoko Pharmaceuticals” in Brazil. Her page for EEn can be found at https://otokonokopharma.com/Estradiol-Enanthate/. She sells EEn in MCT oil in 10 mL vials of 400 mg EEn with a resultant concentration of 40 mg/mL.

Lena and Lilian’s products are frequently used by members of the DIY transfeminine community.

Durations of EEn relative to other major parenteral estradiol esters are as follows (Wiki-Table):

Estradiol esterAbbr.FormDuration by dose (i.m. injection)
Estradiol benzoateEBOil soln.5 mg ≈ 4–6 days
Estradiol valerateEVOil soln.5 mg ≈ 7–8 days | 10 mg ≈ 10–14 days
Estradiol cypionateECOil soln.5 mg ≈ 11–14 days
Estradiol enanthateEEnOil soln.10 mg ≈ 20–30 days
Estradiol undecylateaEUOil soln.10–20 ≈ 40–60 days | 25–50 ≈ 60–120 days
Polyestradiol phosphateaPEPAq. soln.40 ≈ 30 days | 80 ≈ 60 days | 160 ≈ 120 days

a Note that both estradiol undecylate and polyestradiol phosphate have been discontinued and are no longer available. Polyestradiol phsphate had limited availability and was recently discontinued (Reddit; Reddit).

And here is a graph comparing EEn and a few other parenteral estradiol esters:

Figure: A simplified graphical representation of the time–concentration curves of EEn and a few other estradiol esters after a single intramuscular injection of 5 or 10 mg in oil solution (Wiki-Graph; Garza-Flores, 1994). The doses chosen are the common doses used in combined injectable contraceptives.

Some additional time–concentration curves for EEn can be found here. As can be seen, EEn lasts longer than other commonly used parenteral estradiol esters and can be injected less frequently. It can also allow for steadier estradiol levels and less variation than other estradiol esters.

A structural comparison of EEn with other estradiol esters can be found here. Basically, EEn has a couple more carbon atoms added to the fatty acid ester moiety compared to EV. This makes it more fat-soluble and hence last longer with intramuscular or subcutaneous injection (which form a long-lasting depot in muscle and/or fat tissue at the site of injection).

For high-dose parenteral estradiol monotherapy, a dose of EEn of 10 mg once every 2 weeks by i.m. injection may be a good regimen (Aly W., 2020). A 3-week dosing regimen, for instance with 15 mg per dose, may also be feasible although with greater variation in estradiol levels. It should be noted that the dosages of parenteral estradiol esters recommended by Lena and Lilian (e.g., 7 mg/5 days for EV) are excessive and may pose unnecessary health risks (Aly W., 2020; Sam S., 2020).

EEn is a favorable choice relative to other commmonly used estradiol esters when a longer injection interval is desired. With that said however, it should be cautioned that these EEn products are homebrewed preparations not subject to regulations and their quality and safety are not guaranteed. We do not endorse the use of these products and only seek to inform.