What are Hormones?
A hormone is a chemical messenger that is secreted (or released) into our bloodstream by specific organs known as glands – three are found in the brain and seven in the rest of the body. They regulate
or control many different processes in our body, including blood glucose levels, metabolism, the water content in blood, general growth, sleep, blood pressure, and many more. Hormones produce a specific response when they reach the target organ. Generally speaking, sex hormones are responsible for growth, maintaining, and regulating the sexual cycle, how we experience
puberty, moods, and the reproductive process.
Female Sex Hormones
The roles your hormones play change over time because it is natural and expected. They change as you leave childhood and enter puberty, and change dramatically if you become pregnant, give birth, or are
breastfeeding. They also continue to change as you near menopause.
The six female sex hormones that work to regulate and balance the sexual cycle are:
1. Estrogen – responsible for the development and regulation of the female reproductive system, primary and secondary sex characteristics. It also plays a role in bone metabolism and liver
2. Progesterone – regulates the monthly menstrual cycle and plays an important role in the preparation of the endometrium for implantation of a fertilized ovum and maintenance of
3. Testosterone – increases vaginal blood flow and lubrication which boosts sexual desire (libido). It also helps regulate the menstrual cycle and maintain bone and muscle strength.
4. Inhibin – it is released from the ovaries and decreases the production of Follicle-stimulating hormone (FHS) which plays an important role in sexual development and functioning,
controlling the menstrual cycle and stimulating the growth of eggs in the ovaries.
5. Activin – it has an effect that is opposite to Inhibin and increases the production of FHS.
6. Follistatin – decreases the activity of Activin by binding to it and its overall effect is to decrease FHS secretion.
Roles of Hormones
● Puberty – when an increase in female sex hormones results in the development of breasts, growth of pubic and armpit hair and overall growth spurt, an increase in body fat, the
maturation of the ovaries, uterus, and vagina and the start of the menstrual cycle.
● Menstruation – begins with menarche and is identified by the following phases – follicular phase, ovulatory phase and luteal phase every month as the uterus thickens in preparation for a
fertilized egg and eventually sheds its lining when an egg is not fertilized.
● Sexual desire (Libido) – estrogen, progesterone, and testosterone all play a role in female sexual desire and sexual functioning. Due to hormonal fluctuations, sexual desire is at its peak
just before ovulation.
● Pregnancy – in this period progesterone thickens the cervix to protect the uterus from bacteria and sperm. Estrogen levels are also higher, contributing to the thickening of the lining of the
uterus. Both hormones help milk ducts in the breasts to dilate.
● Postnatal – hormone levels start to fall immediately after pregnancy. Breastfeeding lowers estrogen levels and can prevent ovulation but this isn’t always the case. This significant fall in
hormones may also contribute to postpartum depression.
● Perimenopause and menopause – in the period leading up to menopause, hormone production in your ovaries slows down. Estrogen levels begin to fluctuate while progesterone
levels start a steady decline.
We will experience hormonal fluctuations throughout our life cycle however some conditions may have more serious implications on the normal function of our hormones:
● Polycystic ovary syndrome (PCOS) – a hormonal disorder common among women of reproductive age.
● Hypogonadism (gonad deficiency) – when sex glands called gonads produce little if any, sex
● Androgen excess – an overproduction of male hormones that can cause menstrual irregularities, infertility, acne, and male pattern baldness.
● Hirsutism – an increase in hair growth on the face, chest, abdomen, and back caused by excessive male hormones and sometimes a symptom of PCOS.
● Estrogen deficiency – include menopausal symptoms, vaginal and endometrial atrophy, and osteoporosis.
● Excess estrogen levels may also have adverse effects, including gynecomastia, thrombosis, and an increased risk of breast and endometrial cancer.
● Low progesterone levels – irregular periods and short cycles, ectopic pregnancy and miscarriage.