Estrogen Explained: The Key Hormone Behind a Woman's Health and Fertility

In short: Oestrogen is the hormone responsible for female characteristics. It is made mainly by the ovaries and controls the growth of the breasts and uterus, ovulation, bone health, vaginal moisture and the elasticity of the skin. Too much can cause heavy periods and fibroids; too little causes hot flushes, vaginal dryness, bone thinning and mood swings. It is used medically to treat menopause symptoms and in contraception.

Estrogen is the hormone best known for shaping female characteristics in a woman’s body, and many patients ask us whether it can be used as a treatment to support or enhance these features. Understanding how estrogen works can help you recognize when your body may need extra care, and when it’s time to speak with a specialist.

Functions of estrogen:

• Breast development
• Growth of the uterus and fallopian tubes
• Building the uterine lining during the menstrual cycle
• Regulating ovulation
• Increasing the level of good cholesterol in the blood
• Maintaining the elasticity of blood vessels
• Regulating sleep
• Enhances cognitive abilities
• Maintains skin thickness and elasticity
• Reduces hair thinning
• Maintains bone density
• Prevents mood swings
• Maintains vaginal lubrication

• Supports the health of the urethra and bladder lining

Sources of estrogen production:

• Ovaries
• Placenta during pregnancy
• Body fat
• Adrenal glands

Types of estrogen:

• Estrone (E1): The primary type after menopause, made mainly in body fat
• Estradiol (E2): The most potent and dominant type during the reproductive years
• Estriol (E3): The primary type during pregnancy, made by the placenta

What happens when estrogen levels in the body are abnormal?

High estrogen levels in the blood can lead to:

• Heavy menstrual bleeding
• Breast tenderness and swelling
• Increased risk of uterine fibroids * Increased risk of endometrial and breast cancer

Low estrogen levels in the blood can lead to:

• Hot flashes
• Vaginal dryness
• Osteoporosis
• Mood swings
• Irregular or absent menstrual cycles
• Heart problems

Are there any medical uses for estrogen?

Yes, estrogen therapy may be considered for several situations, always under medical supervision:

• Hormone replacement therapy for menopause
• It is present in birth control pills
• Treatment of amenorrhea (absence of menstruation)
• Prevention of osteoporosis

It should be noted that women who still have a uterus and take estrogen tablets, patches or gel must also take a progestogen to prevent thickening of the uterine lining and endometrial cancer. Women who have had a hysterectomy can take estrogen alone, and low-dose vaginal estrogen does not usually need a progestogen.

What are the contraindications for using estrogen as a treatment?

• Breast cancer
• Cancers with estrogen receptor-sensitive cells
• A current or past blood clot (DVT or pulmonary embolism), or a known clotting disorder (thrombophilia)
• Unexplained vaginal bleeding
• Active liver disease
• A recent heart attack or stroke

In what conditions does a woman’s body lose estrogen?

[* - Premature ovarian insufficiency (loss of ovarian function before age 40)

• Menopause
• Surgical removal of the ovaries

What forms of estrogen are available in pharmacies?

• Pills
• Transdermal patches
• Vaginal rings, creams, or suppositories

It is not recommended to use estrogen without consulting a doctor due to potential risks in some cases. If you have questions about your hormone levels, menstrual cycle, or fertility, Dr. Najeeb Layyous and his clinical team are available to guide you through safe, personalized evaluation and care.

Dr Najeeb Layyous F.R.C.O.G

Consultant Obstetrician, Gynecologist and Infertility Specialist