Estrogen conjugate

An estrogen conjugate is a conjugate of an endogenous estrogen. They occur naturally in the body as metabolites of estrogens and can be reconverted back into estrogens. They serve as a circulating reservoir for estrogen, particularly in the case of orally administered pharmaceutical estradiol. Estrogen conjugates include sulfate and glucuronide conjugates of estradiol, estrone, and estriol:

Double conjugates like estriol sulfate glucuronide can also be formed.

Estrogen conjugates are conjugated at the C3, C16α, and/or C17β positions.

Estrogen conjugates have been used as pharmaceutical estrogens, as in estrone sulfate as estropipate (piperazine estrone sulfate) and in conjugated equine estrogens (Premarin) and estriol glucuronide in Progynon and Emmenin.