Conjugated estrogens (brand name Premarin), an estrogen product manufactured from the urine of pregnant mares and commonly used in menopausal hormone therapy, is a mixture of natural estrogens including estrone sulfate and equine estrogens such as equilin sulfate and 17β-dihydroequilin sulfate.

oestrogen – which is taken from either plants or the urine of pregnant horses. progesterone – HRT uses a synthetic version of progesterone called progestogen, which is easier for the body to absorb.

Before menopause (pre-menopause) oestrogen is made mainly by the ovaries. Around the time of menopause (peri-menopause), the ovaries stop making female hormones, including oestrogen. This usually happens when women are in their late 40’s and early 50’s.

Estrogens, in females, are produced primarily by the ovaries, and during pregnancy, the placenta. Follicle-stimulating hormone (FSH) stimulates the ovarian production of estrogens by the granulosa cells of the ovarian follicles and corpora lutea.

Having too much oestrogen can lead to minor problems such as acne and constipation, or more serious conditions such as breast cancer. Having too little oestrogen can cause problems such as poor bone growth and menopausal symptoms.

In addition to regulating the menstrual cycle, estrogen affects the reproductive tract, the urinary tract, the heart and blood vessels, bones, breasts, skin, hair, mucous membranes, pelvic muscles, and the brain.

Estriol (E3) and estradiol (E2) are two different forms of the female hormone known as estrogen (sometimes referred to as oestrogen). These forms of estrogen are steroid hormones that are naturally found in the body. Estriol and estradiol can be used as hormone replacement therapy (HRT) for women after menopause.

Plasma leptin levels decrease during fasting[8] or energy restriction[9] and increase during refeeding,[10] overfeeding,[11] and surgical stress. [12,13] Insulin, glucocorticoids, serotonin, and estrogen have been reported to stimulate leptin secretion.