What You Need to Know About Female Hormones
Female sex hormones, or sex steroids, play vital roles in sexual development, reproduction, and overall health.
Sex hormone levels change over time, but some of the most important changes occur during puberty, pregnancy, and menopause.
What Are Sex Hormones?
Hormones are chemical messengers produced by the endocrine glands and secreted into the bloodstream. Hormones help regulate many body processes such as appetite, sleep, and growth.
Sex hormones play an important role in sexual development and reproduction. The main glands that produce sex hormones are the adrenal glands and the gonads, which cover the ovaries in females and the testes in males.
Sex hormones are also important for bodily functions and general human health. In both men and women, sex hormones are as follows:
- Puberty and sexual development
- Regulates bone and muscle development
- Inflammatory responses
- regulating cholesterol levels
- promoting hair growth
- Body fat distribution
Sex hormone levels fluctuate throughout a person’s life. Factors that can affect the levels of female sex hormones include:
- menstrual cycle
Sex hormone imbalances can lead to sexual desire and health problems such as hair loss, osteoporosis and infertility.
Types of Female Sex Hormones
In women, the ovaries and adrenal glands are the main producers of sex hormones. The female sex hormones include estrogen, progesterone and small amounts of testosterone.
Estrogen is probably the best known sex hormone.
Although the majority of estrogen production occurs in the ovaries, the adrenal glands and fat cells also produce small amounts of estrogen. Estrogen plays an important role in reproductive and sexual development, which begins when a person reaches puberty.
The ovaries, adrenal glands, and placenta produce the hormone progesterone. Progesterone levels increase during ovulation and experience a spike during pregnancy.
Progesterone helps stabilize the menstrual cycle and prepares the body for pregnancy. Having low progesterone levels can cause irregular periods, difficulty getting pregnant, and a higher risk of complications during pregnancy.
Although testosterone is the main sex hormone in men, it is also found in low amounts in women.
In women, testosterone affects:
- Tissue and bone mass
- red blood cell production
The Role of Female Sex Hormones in Adolescence
During puberty, the body produces more estrogen and progesterone.
Women typically enter puberty between the ages of 8 and 13, and puberty usually ends around age 14.
During puberty, the pituitary gland begins to produce greater amounts of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which stimulate the production of estrogen and progesterone.
Increased estrogen and progesterone levels initiate the development of secondary sexual characteristics, including:
- breast development
- Hair growth in the armpits, legs and groin area
- elongation in length
- Fat storage in the hips, hips and thighs
- Enlargement of the pelvis and hips
- Oily skin
The Role of the Menstrual Cycle
Menarche is a person’s first menstrual period and usually occurs between the ages of 12 and 13. However, menarche can occur anytime between the ages of 8 and 15.
After menarche, many people have regular menstrual cycles until they reach menopause. Menstrual cycles are usually around 28 days, but can range from 24 to 38 days.
The menstrual cycle takes place in three phases that coincide with hormonal changes:
The first day of a period marks the beginning of a new menstrual cycle. Over a period of time, blood and tissue from the uterus exits the vagina through the body. Estrogen and progesterone levels are very low at this point and this can cause irritability and mood changes.
The pituitary gland also releases FSH and LH, which raise estrogen levels and signal follicle growth in the ovaries. Each follicle contains an egg. After a few days, a dominant follicle will emerge in each ovary. The ovaries absorb the remaining follicles.
As the dominant follicle continues to grow, it will produce more estrogen. This increase in estrogen stimulates the release of endorphins that raise energy levels and improve your mood.
Estrogen also enriches the endometrium, the lining of the uterus in preparation for a potential pregnancy.
During the ovulation phase, estrogen and LH levels in the body allow a follicle to burst and release its egg from the ovary.
An ovary can survive for about 12 to 24 hours after it leaves the ovary. Fertilization of the egg can occur only during this time interval.
In the luteal phase, the egg travels from the ovary to the uterus via the fallopian tube. The ruptured follicle releases progesterone, which thickens the uterine lining, preparing to receive a fertilized egg. When the egg reaches the end of the fallopian tube, it attaches to the uterine wall.
An unfertilized egg causes estrogen and progesterone levels to drop. This marks the beginning of the premenstrual week.
Finally, the unfertilized egg and uterine lining leave the body, marking the end of the current menstrual cycle and the start of the next.
The Role of Female Sex Hormones in Pregnancy
Pregnancy begins when a fertilized egg implants in the uterine wall. After implantation, the placenta begins to develop and produce a number of hormones, including progesterone, relaxin, and human chorionic gonadotropin (hCG).
Progesterone levels increase steadily during the first few weeks of pregnancy, causing the cervix to thicken and form a mucus plug.
Progesterone production prevents contractions in the uterus until the end of pregnancy, at which point it helps relax the ligaments and tendons in the pelvis.
Rising levels of hCG in the body then stimulate the production of estrogen and progesterone.
This rapid rise in hormones leads to early pregnancy symptoms such as nausea, vomiting and more frequent urination.
Estrogen and progesterone levels continue to rise during the second trimester of pregnancy. At this time, the cells in the placenta will begin to produce a hormone called human placental lactogen (HPL). HPL regulates women’s metabolism and nourishes the growing fetus.
Hormone levels drop as the pregnancy ends and gradually returns to pre-pregnancy levels. When a mother breastfeeds, it can lower estrogen levels in the body, which can prevent ovulation from occurring.
The Role of Female Sex Hormones in Menopause
Menopause can cause difficulties in sleeping. Menopause occurs when the person no longer menstruates and loses fertility. In the United States, the average age at which a woman reaches menopause is 52.
Perimenopause refers to the transitional period leading up to the person’s last menstrual period. During this transition, large fluctuations in hormone levels can cause a person to experience a variety of symptoms.
Symptoms of perimenopause may include:
- Irregular menstruation
- hot flashes
- sleep difficulties
- mood changes
- vaginal dryness
According to the Office of Women’s Health, perimenopause usually lasts about 4 years but can last from 2 to 8 years.
A person enters menopause when a full year has passed after perimenopause. After menopause, the ovaries will only produce very small but constant amounts of estrogen and progesterone.
Low estrogen levels can reduce a person’s sex drive and cause bone density loss that can lead to osteoporosis. These hormonal changes can also increase the risk of heart disease and stroke.
The Role of Sexual Desire and Arousal
Estrogen, progesterone, and testosterone all affect sexual desire and arousal. Having higher estrogen levels in the body supports vaginal lubrication and increases sexual desire. Increases in progesterone can reduce sexual desire.
There is some controversy over how testosterone levels affect female sex drive.
Low testosterone levels can cause decreased sexual desire in some women. However, testosterone therapy is not effective in treating low sex drive in women.
According to a systematic review from 2016, testosterone therapy can increase the effects of estrogen, but only if a doctor keeps testosterone above normal levels. This can cause unwanted side effects.
These side effects can include:
- Gaining weight
- Hair loss
- excessive facial hair
- clitoral enlargement
- hormonal imbalance
Hormonal balance is important for overall health. Although hormonal levels fluctuate regularly, long-term imbalances can lead to many symptoms and conditions.
Signs and symptoms of hormone imbalances may include:
- Irregular periods
- Excess body and facial hair
- vaginal dryness
- low sex drive
- breast tenderness
- gastrointestinal problems
- hot flashes
- night sweats
- Gaining weight
- Irritability and erratic mood changes
- difficulty sleeping
Hormonal imbalances can be a sign of an underlying health condition. Also, some medications can have side effects. Therefore, people who experience severe or recurrent symptoms of hormonal imbalance should consult a doctor.
Potential causes of hormonal imbalances in women include:
- polycystic ovary syndrome
- primary ovarian failure
- hormonal birth control
- hormone replacement therapy
- excessive body weight
- ovarian cancer
What Are Female Sex Hormones Summary
Hormones are chemical messengers that regulate body functions and maintain overall health. Sex hormones play an important role in sexual development and reproduction.
In women, the main sex hormones are estrogen and progesterone. The production of these hormones mostly occurs in the ovaries, adrenal glands, and placenta during pregnancy.
Female sex hormones also affect body weight, hair growth, bone resorption and muscle growth. Although these hormones naturally fluctuate throughout a person’s life, long-term imbalances can cause a variety of symptoms and health effects.
MedicalNewsToday, What to know about female sex hormones, 2019
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