Why Progesterone Might Be Key to Understanding Autoimmune Problems in Women
If you’ve ever wondered why autoimmune diseases seem to affect way more women than men, you’re not alone. In fact, about 80% of people with autoimmune conditions are women. That’s a huge difference—and a big part of the reason comes down to hormones, especially progesterone.
What Is Autoimmune Disease?
First, a quick look at what autoimmune diseases actually are. Normally, your immune system protects you by fighting off germs and infections. But in autoimmune diseases, the immune system gets confused and starts attacking your own body’s cells and tissues by mistake. This can lead to inflammation, pain, and damage in different parts of the body, depending on the condition.
Examples include rheumatoid arthritis, lupus, multiple sclerosis, and Hashimoto’s thyroiditis.
What Is Progesterone, Anyway?
Progesterone is a hormone mostly known for helping with your menstrual cycle and pregnancy. But it actually does a lot more, especially when it comes to your immune system.
During pregnancy, progesterone’s job is to keep your body from “rejecting” the growing baby. It tells your immune system, “Hey, this is safe, don’t attack!” So instead of fighting off what it thinks is a foreign invader, your body learns to chill out and protect the new life.
Progesterone and Your Immune System
Your immune system is like your body’s defense team. It fights germs and infections but also needs to know when to hold back so it doesn’t attack your own tissues. That’s where progesterone comes in—it helps calm things down and keeps your immune system balanced.
Here’s how it works:
It quiets down the parts of the immune system that cause inflammation.
It boosts the “peacekeeper” cells that tell your immune system to chill out.
It helps create more anti-inflammatory signals, keeping things from going haywire.
When progesterone levels drop, especially if estrogen is high (a situation called estrogen dominance), the immune system can get a bit out of control. That’s one reason women are more likely to develop autoimmune diseases.
What Does Estrogen Do to Your Cells?
Estrogen is often called the “growth hormone” because it encourages cells to grow and divide. That sounds good, but there’s a catch. When cells are pushed to grow and divide too much or too fast, especially without enough balance from progesterone, it can cause stress inside the cells. Here’s what happens:
Increased cell division: Estrogen signals cells to multiply, which is necessary for things like the menstrual cycle. But too much can lead to overgrowth in tissues, which might contribute to things like thicker uterine lining or even some kinds of tumors.
Protein folding stress: Cells have to make lots of proteins to grow and divide. Estrogen can push cells to work harder, which sometimes causes proteins to fold incorrectly—this stresses the cell and can trigger inflammation.
More reactive molecules: Rapid growth can lead to more free radicals and oxidative stress, which can damage cells and DNA if not balanced properly.
Here’s where progesterone’s role becomes even more important:
When progesterone is present, it helps balance the rapid cell growth that estrogen encourages, making sure cells grow and divide at a healthy, controlled pace. This balance prevents the kind of cellular chaos that can stress the body and cause problems down the line.
On top of that, progesterone helps your body “recognize” stressed or abnormal cells as part of the normal tissue. This promotes immune tolerance, so your immune system doesn’t mistakenly attack these cells. But when progesterone is low or missing, the immune system may misinterpret these unusual cells as threats and try to push them away — which can lead to inflammation and potentially trigger autoimmune reactions.
Why Do Women Get Better During Pregnancy?
Funny thing: many women with autoimmune conditions like rheumatoid arthritis or multiple sclerosis actually feel better when they’re pregnant. Why? Because during pregnancy, progesterone levels go way up, helping the immune system calm down and stop attacking the body. Plus, estrogen dominance eases, creating a more balanced hormone environment.
How Birth Control Can Mess with Your Progesterone and Immune Health
A lot of women use hormonal birth control to manage periods, acne, or simply to avoid pregnancy. While birth control pills and similar methods can be helpful, they often work by suppressing your body’s natural progesterone production.
Here’s the thing: most birth control pills contain synthetic versions of estrogen and/or progestin (a man-made hormone similar to progesterone), but these don’t act anything like your body’s own progesterone. Even more, many types of birth control shut down ovulation, which means your ovaries stop making natural progesterone altogether.
When your natural progesterone levels drop, your immune system loses some of that calming influence we talked about earlier. This can contribute to:
Increased inflammation
Hormone imbalances
Worsening autoimmune symptoms in some women
Plus, since your body isn’t producing its own progesterone, estrogen dominance can become more of a problem. That’s when estrogen is high compared to progesterone, which can throw your immune system—and your whole body—out of balance.
So while birth control can help with some symptoms, it’s important to understand that it may also affect your hormone balance and immune health in ways that aren’t always obvious.
What Happens When Progesterone Is Low?
Lots of women have low progesterone at some point—due to stress, birth control pills, or natural hormonal changes. When that happens, the immune system loses some of its “chill factor.” This can lead to more inflammation and might make autoimmune symptoms worse.
How Can You Support Healthy Progesterone?
You don’t have to wait for pregnancy to balance your hormones. Here are some ways to help support healthy progesterone levels:
Manage stress — chronic stress can tank your progesterone.
Get good sleep — your body needs rest to make hormones.
Eat nutrient-rich foods — zinc, magnesium, and vitamin B6 are key players.
Avoid hormone disruptors — things like certain plastics and chemicals can mess with your balance.
The Big Picture
Autoimmune problems are complex, but hormones—especially progesterone—play a huge role. By understanding how progesterone helps keep your immune system in check and how estrogen dominance can throw things off, we get a clearer picture of why so many women struggle with these issues. And maybe more importantly, how finding that balance can make a real difference.
