How Hormones Affect Our Immune System

by May 7, 2020

The sex hormones estrogen, testosterone, and progesterone are known to play a role in the way that our bodies respond to sex and fertility. However, these same hormones play a much bigger role in the way our bodies function. Our sex hormones play in our bodies is related to our immune system and how it functions.

a woman in a har and blanket

How our immune system works

The goal of our immune system is to protect us as best it can and is made up of two systems dedicated to this.

The nonspecific immune system that protects us from antigens, has barriers that keep materials from entering the body and is the first line of defense.

The specific immune system is also known as acquired immunity, this is developed over time after different experiences with different infections as we are exposed to them.

How does each sex hormone affect the immune system?

Testosterone is known as an immunosuppressant, which makes men more susceptible to infections.  An article was written by Stanford Medical shows high levels of testosterone in men are linked to a lower immune system.

Progesterone also works as an immunosuppressant. High levels of progesterone also cause an increased risk of infections and overall lowers the immune system.

Estrogen, on the other hand, has an immunoenhancing effect and can affect the immune system in many different ways that we’ll discuss below

Types of estrogen

There are different types of estrogen in our bodies, and they all have different effects on the body.

Estrone is found in the body post-menopause. The other types of estrogen can change estrone into other types of estrogen if needed.

Estriol is an estrogen produced in the body during pregnancy.

Estradiol is the type of estrogen produced by both men and women and is what is usually referred to when we talk about estrogen. And this is the type of estrogen we will focus on in this article.

How Estrogen affects your body

As a quick overview,  even though we’re focusing on estrogen in this article, sex hormones also include testosterone and progesterone.

Estrogen (Estradiol) is typically known as a female hormone, however, estrogen is also found in males. While both sexes create the hormone, women produce more of it and that is what we’ll focus on in this article.

When we think of estrogen, we usually link it to our sexual and reproductive health.

However, estrogen plays a much bigger role in our bodies than we usually hear about. Estrogen contributes to our cardiovascular health, and cognitive health as well.

Estrogen is produced in our ovaries, fat tissues and adrenal glands.

It regulates our menstrual cycles, controls the growth of our uterine lining during our first part of the menstrual cycle, and plays a role in our overall body development when we first begin puberty.

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When it comes to the immune system estrogen can potentially cause negative effects

The female hormone estrogen is said to have an immunoenhancing effect on the immune system. Which means it can help us get less than men when it comes to viral infections. This also makes our bodies much stronger in fighting off viruses in the future.

On the other hand, too much estrogen can also wreak havoc on a woman’s immune system, causing her body to even fight against its self.

A study performed showed that estrogen in some cases has contributed to women being affected with autoimmune diseases.

According to, women appear to be more likely to develop autoimmune diseases like systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis, and grave disease to name a few.

While there’s still more search that needs to be done there’s reason to believe the sex hormone estrogen may contribute to this increased risk for women (we also wrote a post on Autoimmune Diseases and Pregnancy).

Estrogen also can have effects on a woman’s immune response during pregnancy, and even our circadian rhythm.

Does your period affect your immune system?

It’s likely that your period does, in fact, affect your immune system.

A  study shared on PubMed suggests that women can actually get sicker during their menstrual cycle. The study goes on to note that its possible women may notice a flare-up in autoimmune disease during their cycle as well.

These flareups can be contributed to the fluctuation of progesterone and estrogen during your menstrual cycle.

With so many ways that estrogen affects your overall health, it can bring up a few questions.

Does this mean there’s an estrogen imbalance?

Without seeking medical help, it’s difficult to say whether or not you could have an estrogen imbalance, so it’s always recommended to speak with your doctor.

Having high levels of estrogen can cause symptoms such as:

  • Weight gain
  • Irregular periods
  • Heavy bleeding during periods
  • Hair loss
  • Fatigue
  • Headaches
  • Low sex drive
  • Mood changes
  • Noncancerous breast lumps


In women experiencing low estrogen, they’re likely to experience:

  • Infertility
  • Painful sexual intercourse
  • Hot flashes
  • Urinary tract infection (UTI)
  • Weight gain mainly in the abdomen.
  • Vaginal dryness


Your doctor can help you figure out whether or not you have abnormal levels of estrogen by performing a blood test.

Whether your levels are actually too high or too low will determine the type of treatment that will be best for you.  The symptoms above can also be caused by other health issues, which is why it’s important to talk with a medical professional for a clear answer.


Estrogen plays a big role in not only our fertility but overall health. Being aware of not only the positive but negative effects estrogen can play in our lives is important and can help you better understand how your body works.

Always consult with your doctor when it comes to figuring out whether or not there could be issues such as high or low levels of estrogen.

As we learn more about estrogen and how it operates with our body, we can help women that struggle with imbalances and autoimmune diseases to find better solutions.

✔️ Medically Reviewed by Banafsheh Kashani, MD, FACOG

Banafsheh Kashani, MD, FACOGBanafsheh Kashani, M.D., FACOG is a board-certified OB/GYN and specialist in reproductive endocrinology and infertility at Eden Fertility Centers, and has been treatingcouples and individuals with infertility since 2014.

Dr. Kashani has conducted extensive research in female reproduction, with a specific focus on the endometrium and implantation.

Additionally, Dr. Kashani has authored papers in the areas of fertility preservation, and fertility in women with PCOS and Turners syndrome. She also was part of a large SART-CORS study evaluating the trend in frozen embryo transfers and success rates.

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