If you're struggling with strange symptoms and wondering what is happening to your body, you are not alone. Perimenopause is a major hormonal shift that can cause everything from mood swings and insomnia to weight gain and brain fog.
Before diving into lab results and hormone tests, it helps to understand what hormones are actually changing in your body, and why.
The Key Hormones Involved in Perimenopause
We are going to look at five main hormone groups that influence how you feel during perimenopause:
- Reproductive hormones (estrogen and progesterone)
- Stimulating hormones (FSH and LH)
- Adrenal hormones (DHEA and cortisol)
- Insulin and testosterone
- Thyroid hormones
Let’s break it all down.
Reproductive and Stimulating Hormones
Your ovaries are slowing down. As a result, your body makes less estrogen and progesterone, and this causes a ripple effect.
Two important hormones called FSH (follicle-stimulating hormone) and LH (luteinizing hormone) come from the pituitary gland in your brain. These are not true hormones themselves. Instead, they act like messengers, telling your ovaries when to produce estrogen and progesterone.
Your brain is constantly monitoring your hormone levels. When estrogen and progesterone drop, your brain increases FSH and LH to try to get the ovaries to respond. If the ovaries are no longer functioning properly (or have been removed), the brain keeps raising the volume, sending more and more FSH and LH.
This is called a negative feedback loop. The lower your hormone levels, the louder the brain calls out for more.
- In a healthy cycle, FSH and LH are typically between 2 to 9.
- In menopause or after ovary removal, those levels can jump to 70 or even over 100.
- If you are taking high-dose hormone therapy or are pregnant, FSH and LH drop very low, often below 1.
Estrogen and Progesterone
You have three main types of estrogen:
- Estrone (E1): Made in fat tissue and the least active.
- Estradiol (E2): The strongest form, made mainly in the ovaries.
- Estriol (E3): A gentler form, with benefits for skin and hair.
Estradiol supports almost every system in your body, including:
- Brain and memory
- Bones and heart
- Skin, hair, and vaginal health
Progesterone is released after ovulation, usually around day 14 of your cycle. It is deeply calming and helps you sleep, stay balanced, and counteract the effects of estrogen.
When ovulation becomes irregular in perimenopause, progesterone drops. This leads to:
- Trouble sleeping
- Anxiety and irritability
- Estrogen dominance
- Heavier periods
Adrenal Hormones: DHEA, Cortisol, and Pregnenolone
Your adrenal glands are small glands that sit on top of your kidneys. They play a big role in stress response and hormone balance — especially during perimenopause.
DHEA
- Produced by the adrenal glands
- Converts into estrogen and testosterone as needed
- Helps with energy, libido, and skin health
Cortisol
- Your primary stress hormone
- Should be high in the morning, and low at night
When cortisol is out of balance, it can cause:
- Anxiety
- Insomnia
- Belly fat
- Fatigue or burnout
Here is the kicker. Cortisol raises blood sugar, even when you don’t eat. That triggers insulin, which stores fat. So if you are stressed but not burning off the energy, your body stores it as fat. This is a major reason why women gain weight during perimenopause.
Pregnenolone
- A hormone precursor made in the adrenal glands and brain
- Supports focus, memory, and mental clarity
- Declines with age and stress
When pregnenolone is low, you may struggle with memory, mental energy, and word recall.
Testosterone
Testosterone is not just for men. Women need it too, in smaller amounts. Most female testosterone comes from the adrenal glands through DHEA. It supports:
- Confidence
- Muscle mass
- Sex drive
In perimenopause, testosterone often drops due to stress and adrenal fatigue, not necessarily due to aging. Low testosterone may show up as low motivation, poor libido, and fatigue.
Thyroid Hormones
Your thyroid regulates metabolism, energy, mood, and body temperature. Thyroid problems can get worse in perimenopause, or even be triggered by it.
Important markers to test:
- TSH (thyroid-stimulating hormone): Comes from the brain and helps control thyroid output.
- Free T4: The inactive hormone produced by the thyroid.
- Free T3: The active hormone that drives metabolism and energy.
- Reverse T3: An inactive byproduct that blocks the effects of T3.
Your thyroid makes mostly T4, which must convert into T3. If it cannot convert properly, you may feel tired, sluggish, or gain weight. Estrogen and progesterone decline during perimenopause, and this puts pressure on the thyroid.
Some women also develop Hashimoto’s disease, an autoimmune thyroid condition triggered by hormone shifts. It is important to test for thyroid antibodies:
- TPO antibodies
- TgAB (thyroglobulin antibodies)
Why This Matters
Perimenopause is not just a phase. It is a complete hormonal reset. Understanding your lab results makes a huge difference in how you manage symptoms and what kind of support you may need — whether that is lifestyle changes, targeted supplements, or medical guidance.
In our next guide, we will walk through how to test your hormones and what your results really mean.