Estradiol Undecylate is an estered form of bioidentical estradiol suspended in an oil solution making it suitable for subcutaneous and intramuscular injections. Esterification is the process of combining Estradiol with an acid which the human body will then slowly break down over time, creating a slow-release form of the medication so that it can be delivered as larger injections at lower frequencies, typically around weekly. Estradiol has been delivered in this form for almost a century and it's a well-studied, safe and convenient process. Estradiol Undecylate has a biological half-life of ~30 days.

Unlike many other medications on this site, these products are produced by private individuals, not pharmaceutical companies, and thus do not have the associated safety guarantees. While we only list providers with a positive reputation within the DIY community it's important to understand these risks so that you can make an informed decision.

This product is 5ml of liquid, at a concentration of 100mg per ml, for a total of a 500mg per vial.