functions of hormones

Hormonal Blueprint: What Role Do Hormones Play in the Menstrual Cycle?

Hormones play an important role in regulating and managing women’s menstrual cycles. Both estrogen and progesterone are produced by the ovaries and typically ebb and flow throughout a woman’s normal menstrual cycle. 

Not only are hormones important for helping to prepare the uterus for pregnancy, but both estrogen and progesterone help to stimulate the ovaries to produce an egg, which involves various other organs, such as the brain. 

During a normal menstrual cycle, where an egg is not fertilized, progesterone levels will decrease, and signal to the brain that an unfertilized egg is present within the uterine lining. Over the following days, progesterone will begin to prepare the body for menstruation, which is the process that allows the excretion of an unfertilized egg and the shedding of the lining which usually causes bleeding. 

Overview of the Menstrual Cycle Phases

The female menstrual cycle is a highly sophisticated and complex process that involves three different phases:

Phase 1: Follicular Phase 

During this phase both estrogen and progesterone reproductive hormones levels are low, and the top lining layers of the uterus, otherwise known as endometrium, will begin to shed causing menstrual bleeding. Also during this phase, follicle-stimulating hormones (FSH) will slightly increase, and help to stimulate the development of follicles in the ovaries, each of which contains an egg. Over time, FSH will gradually begin to decline, and only one dominant follicle will be left to develop. 

Phase 2: Ovulatory Phase 

In the second phase, there is a natural increase in luteinizing hormone and FSH. During this phase, luteinizing hormone will stimulate egg release, which will in return cause estrogen levels to decrease and progesterone levels to increase. During this time, both luteinizing hormone and FSH levels are high. Another important hormone for reproduction is called gonadotropin-releasing hormone, better known as GnRH

Phase 3: Luteal Phase 

Levels of luteinizing hormone and FSH will begin to decrease, allowing for the ruptured follicle to close and release an egg, helping to form a corpus luteum. This process causes the production of progesterone, and throughout much of this period, estrogen levels are relatively high. Finally, both estrogen and progesterone will help to thicken the lining of the uterus, preparing the body for possible fertilization. 

If an egg is fertilized, the corpus luteum will help to continue to support the function of early pregnancy. On the other hand, an unfertilized egg will mean that the corpus luteum begins to degenerate, causing estrogen and progesterone levels to decrease. This will cause the process to restart, with the top lining breaking apart, and menstrual bleeding occurring and marking the beginning of a new menstrual cycle.

Key Hormones and Their Functions in Menstrual Health

Now that we understand each phase of the menstrual cycle, it’s time to learn more about  which hormone is responsible for menstrual cycle. 

Detailed Analysis of Hormones in the Menstrual Cycle

Estrogen: Its Variants and Impact on Reproductive Health

Estrogen is an important hormone that helps to stimulate the growth of an egg follicle and further helps to stimulate the pituitary gland in the brain. When this occurs, the pituitary gland will help to release hormones that further assist with follicle development. 

The four variants of estrogen include:

  • Estrone (E1): Primary form of estrogen and is formed after menopause. 
  • Estradiol (E2): The most important estrogen for women during their reproductive years. 
  • Estriol (E3): Produced during pregnancy, and helps to regulate pregnancy health. 
  • Estetrol (E4): This is an estrogen that prevents pregnancy by suppressing ovulation.

Take A Look At Estrogen Hormone - The Principal Sex Hormone In Females - Types, Production, Functions In Females: 

Progesterone: The Pregnancy Hormone and Its Role in the Menstrual Cycle

Throughout a normal menstrual cycle, the egg released from the ovary will contain remnants of an ovarian follicle that encloses the developing egg. These remnants are known as the corpus luteum, which helps to release progesterone. 

Progesterone is considered to be the pregnancy hormone because it helps to stimulate the growth of blood vessels that will support the lining of the womb, and further help to supply nourishment for an early embryo. 

Furthermore, progesterone is responsible for helping to prepare the tissue lining of the uterus for a fertilized egg. More than this, there is evidence that has shown progesterone typically supports the health of the endometrium during a normal pregnancy cycle 

Progesterone will continue to be produced by the corpus luteum until the formation of the placenta. This usually occurs around weeks 8-12 of the pregnancy, and by this time the placenta will help support the production of progesterone which is an essential hormone for supporting the pregnancy. 

Testosterone in Women: Lesser-Known Effects on Menstruation and Overall Health

Although testosterone is considered to be primarily a male androgen, this hormone holds several important functions for women’s health. These include both bone and cognitive well-being, help maintain sex drive, and can potentially help to maintain regular periods. 

Too much testosterone in women can be a bad thing and is often associated with polycystic ovarian syndrome (PCOS). In the U.S. roughly 10 percent of women of childbearing age are affected by PCOS, and can cause missed or irregular periods.

On the other hand, a low level of testosterone can cause other health-related concerns including loss of bone density, osteoporosis, increased risk of bone fractures, and feelings of fatigue.

Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH): Triggering Ovulation and Egg Release

There is naturally an increase of both luteinizing hormone and follicle-stimulating hormone or FSH during the ovulatory phase. 

During this phase, luteinizing hormone will stimulate egg release, which will in return cause estrogen levels to decrease and progesterone levels to increase. During this time, both luteinizing hormone and FSH levels are high. 

Levels of luteinizing hormone and FSH will begin to decrease, allowing for the ruptured follicle to close and release an egg, helping to form a corpus luteum. 

This process causes the production of progesterone, and throughout much of this period, estrogen levels are relatively high. Finally, both estrogen and progesterone will help to thicken the lining of the uterus, preparing the body for possible fertilization. 

Interplay of Hormones During Menstrual Phases

During the early phases of the menstrual cycle, both estrogen and progesterone hormones are very low, however, experts suggest that during this time, exercise can help to increase the level of endorphins to help make you feel good. 

Throughout the follicular phase, which is considered the second phase of the menstrual cycle, estrogen levels begin to gradually increase and help to prepare the body for ovulation. From here on out, there might be a slight increase in testosterone, and the combination of high estrogen and slightly increased testosterone levels can help make women feel more motivated and social. 

In the luteal phase, progesterone is considered the main hormone of action and acts as a natural anti-anxiety hormone. Estrogen is also present during these phases, although in lower quantities than compared to the first half of the menstrual cycle. 

Unlike other phases, the pre-menstrual phases usually come with a sharp decline in both estrogen and progesterone and tend to play a role in a woman’s moods, and feelings of fatigue, bloating, and sometimes the feeling of having tender breasts.

Hormonal Imbalances and Menstrual Health Issues

Hormonal levels are constantly in ebb and flow, however, an imbalance may result in additional concerns and health issues that need careful consideration.

Identifying and Addressing Hormone Imbalance

Common identifiers of hormone imbalances include: 

  • Decreased sex drive
  • Changes to skin and hair health
  • An increase in body fat or weight gain
  • Increased feelings of stress or anxiety 
  • Reduced cardiovascular function 

Many of these symptoms can be different for every woman. Treatments such as Hormone Replacement Therapy (HRT) are considered to be the most effective method for alleviating hormonal imbalance and negative side effects that naturally occur alongside it. 

Common Menstrual Irregularities and Hormonal Causes

According to research, menstrual irregularities can occur at any time and may affect women differently. These irregularities may include changes such as: 

  • Perimenopause and/or menopause. 
  • Hormonal birth control, including intrauterine devices (IUDs), pills, and injections. 
  • Uncontrolled or undiagnosed diabetes. 
  • Eating disorders, including anorexia and bulimia. 
  • The presence of too many thyroid hormones produced by the thyroid. 

Impact of Hormonal Imbalance on Overall Health and Well-being

For women, a hormonal imbalance can impact the quality of their life, and result in both near and long-term health-related complications. Some of these complications may be resolved through the intervention of HRT treatment or other reliable treatment options. 

The impact of hormonal imbalance in women can lead to several of the following: 

  • Hair loss or the decline in new hair growth. 
  • Dry, ashy-looking skin. 
  • Feeling tired or fatigued most of the time. 
  • A sudden change in mood. 
  • Issues sleeping such as insomnia. 
  • Hot flashes and night sweats. 
  • Low sex drive or decreased libido. 
  • Difficulty having sex due to vaginal dryness. 
  • Trouble concentrating or feeling of brain fog. 
  • A decrease in bone density and bone loss.

Menopause: Hormonal Changes and Management

During menopause, women may notice some changes taking shape, as this is usually due to a decrease in estrogen hormones and progesterone levels. Both these hormones play an important part in regulating female body health and well-being. As hormonal levels begin to decline, several changes may occur, and lead to women experiencing an assortment of symptoms ranging from hot flashes, night sweats, vaginal dryness, mood swings, and weight gain, among other things. 

Hormone Replacement Therapy (HRT): Costs, Benefits, and Considerations

Hormone Replacement Therapy can help to replenish decreasing levels of estrogen, progesterone, and testosterone. HRT helps to alleviate hot flashes, night sweats, vaginal dryness, anxiety, depression and sleeplessness. 

When using HRT, women under 60 may have an increased risk of breast cancer or blood clotting. While the benefits of HRT typically outweigh the risks, it’s important to consult with an expert or healthcare provider beforehand to better understand any potential long-term health risks. 

Bio-identical HRT treatment can cost anywhere between $200 and $500 per month, although, if your medical aid or healthcare provider can cover the majority of the prescription costs, HRT treatment may set you back around $10 to $100 per month. 

Pros and Cons of HRT for Menstrual and Hormonal Imbalance

Pros 

  • Relief of symptoms experienced during periods of hormonal imbalance. 
  • Improved bone health and decreased risk of bone fractures. 
  • Better overall quality of life and alleviates uncomfortable symptoms
  • Helps to normalize menstrual cycles. 

Cons 

  • Increased risk of breast cancer and blood clots for women under 60 years. 
  • Individual variations may result in different side effects or effectiveness of HRT. 
  • Short-term use can lead to long-term health risks. 
  • Other side-effects such as breast tenderness, headaches, and bloating might be more prevalent. 

FAQ

What Hormones Cause Period to Start?

When an egg is unfertilized, both estrogen and progesterone will begin to decrease and will help to trigger the start of a period.

Final Thoughts

Throughout a woman’s life, all her hormones play an important role in helping to keep her healthy, and active and above all, promote a fertile female reproductive system for when she is ready to conceive and become pregnant. 

Conducting regular health checks with your healthcare provider will ensure that your body is receiving all the nutrients it requires to stay healthy. The better you look after your body, the more it will reward you in the long run. 

 

Sources:

  • KNUDTSON, J. (2018). Menstrual Cycle. MSD Manual Consumer Version; MSD Manuals. https://www.msdmanuals.com/home/women-s-health-issues/biology-of-the-female-reproductive-system/menstrual-cycle

  • Reed, B. G., & Carr, B. R. (2018, August 5). The Normal Menstrual Cycle and the Control of Ovulation. Nih.gov; MDText.com, Inc. https://www.ncbi.nlm.nih.gov/books/NBK279054/‌

 

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