What even is a hormone? And what is their DAMAGE

When you hear the word “hormone”, you probably think of estrogen, testosterone, and maybe progesterone, but there are so many others. Insulin is a hormone, and so are adrenaline, norepinephrine, and cortisol. You probably have heard about or tested your thyroid levels, but maybe don’t know those tests are measuring thyroid hormones like TSH, T3 and T4. There are a veritable buttload of other hormones and they are all enormously fascinating if you are a gigantic nerd.

Hormones are secreted by glands and coordinate vital life functions throughout your body, mostly via the bloodstream. There are also hormone-counting glands throughout your body that detect tiny changes in circulating hormone levels, and produce hormones in response that tell other glands to produce more or less of those hormones. Think of a guy at the door of a bakery counting people coming into the bakery. When a lot of people are coming in he yells to the kitchen “Luigi! More donuts!’ and when customers taper off, he says “Luigi! Smoke break!” That is EXACTLY how your hormone (endocrine) system works. You are basically an endocrinologist now.

And not to play favorites or anything, but to really understand what is happening in wtfopause, there are a handful of hormones that are really crucial to understand, and a much bigger handful that we can skip (better luck next time, glucagon-like peptide 1).

Estrogen, whew. You don’t know what you’ve got ‘til its gone. Estrogen is present and plays a role in reproductive function in people across genders and sexes. It is mainly produced by the ovaries, but also by the adrenal glands and fat cells.

There are three types of estrogen - estrone, estradiol, and estriol. Estrone is the dominant form after menopause. Everyone of reproductive age produces estradiol. Too much estradiol can cause acne, loss of sex drive, osteoporosis, weight gain, irregular periods, PMS, PMDD, and depression. Very high levels can increase the risk of uterine and breast cancer. Low levels can result in weight gain and cardiovascular disease. That’s where the guy yelling at Luigi comes in - really keeping those levels in the exact right range, in a dynamic way and in the face of all the rapid metabolic pressures on a body on any given day (how many people are going in and out of the bakery). Estriol is the dominant type in pregnancy, peaking just before birth and helping the uterus prepare for birth.

The reality is, we don’t know everything estrogen does in the body, and much of its purported actions are extrapolated from how we feel as we run out of it. Generally, estrogen is a nest builder. It stimulates egg growth and ovulation in the ovaries, thickness and lubrication of the vaginal wall, enhances, maintains and regulates uterine mucus secretions, and builds breast tissue. During puberty, increasing estrogen levels increase waist to hip ratio and other body composition changes. Estrogen affects sex drive and ability to maintain an erection. It also has body wide actions involved in regulating cholesterol levels, blood sugar levels, bone and muscle mass maintenance, circulation and blood flow, collagen production, skin moisture, brain function, and ability to focus. You can see why we experience what we experience - as we stop producing so much estrogen, we have declines in all these tissues and actions estrogen is responsible for maintaining. Does that make you want to take estrogen? I get it.

Testosterone is present and plays a role in reproductive function in people across genders and sexes. Believed to be responsible for fetal testicular development and descent, sperm production, and enlargement of the penis and testes. Testosterone is also involved in hair patterns on the head and body, vocal changes, voice deepening, growth spurts in puberty, and skeletal muscle growth. Testosterone stimulates red blood cell production. Testosterone levels tend to drop with increasing age, causing a decrease in testicular size, a drop in libido, lower bone density, muscle mass decline, increased fat production, decreased red blood cell production, and anemia.

Progesterone is secreted after ovulation to try to get you pregnant and keep you pregnant. It thickens the uterine lining (making it stickier for a fertilized egg), prohibits uterine contractions that might reject a fertilized egg. Low levels of progesterone can be responsible for irregular menstruation and frequent miscarriage. Often, progesterone and estrogen are used together in hormone replacement therapy.

Adrenaline and norepinephrine are secreted by the adrenals in times of stress to help us respond with quickness and stamina to threats. Cortisol is secreted by the adrenal cortex to keep adrenaline circulating. Prolonged excessive cortisol levels caused by excessive stress and inadequate exercise lead to belly fat buildup and heart disease. Estrogen is also secreted, in part, in the adrenal glands. Insulin is secreted by the pancreas in response to consumption of sugars and carbs and even things that taste sweet like fake sweeteners (and that creates problems!) and regulates blood sugar levels and fat storage. Insulin resistance has been linked to estrogen levels but the connection isn’t well understood. Thyroid hormone is secreted by the thyroid gland and coordinates tons of actions throughout the body including but not only our pep and stamina, temperature, immune system, and metabolism.