The Basics: Hormones and Hormone Therapy

What Hormones Do

Hormones are chemical messengers your endocrine glands send through the bloodstream. They regulate metabolism, mood, growth, reproduction, and a lot of what happens between. The three you'll hear most about in hormone therapy:

• Estrogen: drives the female reproductive system, regulates the menstrual cycle, and protects bone density.
• Testosterone: the main male sex hormone. Builds muscle, drives libido, and affects mood. Women produce it too, in smaller amounts.
• Progesterone: prepares the uterus for pregnancy and balances estrogen.

Types of Hormone Therapy

• Estrogen therapy: usually for menopausal symptoms like hot flashes and vaginal dryness. Comes as pills, patches, gels, or vaginal creams.
• Testosterone therapy: for low testosterone. Injections, patches, gels, or pellets are all common.
• Combined therapy: estrogen plus progesterone (or a progestin). Used in women who still have a uterus because progesterone protects the endometrial lining.

Who Gets Hormone Therapy

• Menopause and perimenopause: hot flashes, night sweats, mood swings, sleep disruption.
• Gender transition: testosterone for transgender men, estrogen for transgender women.
• Hypogonadism and other hormonal deficiencies: when the body isn't making enough of a given hormone on its own.

Why Bloodwork Matters During Hormone Therapy

Which Tests You'll See

• Estradiol: the main form of estrogen. Tracked closely on estrogen therapy to keep levels effective without overshooting.
• Testosterone: for anyone on testosterone therapy, this is the headline number.
• Progesterone: especially important on combined therapy to keep estrogen balanced and protect the uterine lining.
• Thyroid panel (TSH, T3, T4): thyroid problems can mimic or worsen hormone imbalances, so they're worth ruling out.
• CBC: catches side effects like elevated red cell counts on testosterone or clotting risk on estrogen.

How Bloodwork Shapes Treatment

Most clinicians get a baseline before starting therapy so they have something to compare against. After that, periodic tests answer a few questions:

• Are your levels in the target range?
• If symptoms aren't improving, is the dose too low, or is something else going on?
• Are any side effects starting to show on paper before you feel them?

Based on the answers, your doctor may bump the dose up or down, switch from a patch to an injection, or change formulations.

What Happens If You Skip Monitoring

Going without bloodwork while on hormones is risky. You can drift into too-high or too-low levels and feel it as mood swings, fatigue, or weight changes. Estrogen therapy raises clotting risk, and you want to catch any concerning trends early. Testosterone can push red cell counts up, which becomes a problem if it goes unchecked. Bloodwork isn't optional, it's the part that makes the therapy safe.

Reading the Results

Typical Reference Ranges

Ranges shift with age, sex, and which lab ran the test. Rough numbers to keep in mind:

• Estradiol: 15 to 350 pg/mL in women, depending on cycle phase. Under 30 pg/mL after menopause.
• Testosterone: 300 to 1,000 ng/dL for adult men, 15 to 70 ng/dL for women.
• Progesterone: 1 to 20 ng/mL during the luteal phase. Under 0.5 ng/mL after menopause.
• TSH: 0.4 to 4.0 mIU/L.
• CBC: red cell count, hemoglobin, and white cells all vary by age and sex.

When to Call Your Doctor

Don't wait for the next scheduled visit if you notice:

• Unexplained weight changes, persistent fatigue, mood swings, or libido shifts
• Missed periods or heavy bleeding (if you menstruate)
• New anxiety, depression, or irritability that doesn't track with anything else

Adjusting the Plan

If levels are too low, your doctor will usually raise the dose. Too high, they'll lower it or switch delivery methods. Sometimes a pill isn't absorbing well and a patch works better, or vice versa. The frequency of testing also changes: you'll get tested more often at the start while things settle, then less once your levels are stable.

Getting the Most Out of Your Bloodwork

Before the Draw

• Time it right: estrogen and testosterone levels swing depending on when you took your last dose. Your doctor will tell you whether to test at trough (right before next dose) or at peak.
• Check fasting requirements: not all hormone tests need fasting, but some bundled labs do.
• Tell the team what you're on: every prescription, every supplement. Biotin in particular can interfere with hormone assays.
• Drink water: dehydration makes the draw harder and can shift some readings.

Tracking Your Symptoms

Keep notes between appointments. A short daily log of energy, mood, sleep, libido, and any side effects gives your doctor real information to work with. If you menstruate, note any cycle irregularities. Lifestyle changes (new workout routine, stress, diet shifts) are worth jotting down too because they affect interpretation.

What the Monitoring Schedule Looks Like

Expect frequent tests at the start, maybe every few weeks, until your levels stabilize. After that, every few months is typical. Each visit should include a quick review of your symptom log, your latest results, and any adjustments to dose or delivery.

The Bottom Line

Hormone therapy works best when it's actively monitored. The bloodwork keeps the dose dialed in, flags problems before you feel them, and gives you and your doctor the data needed to adjust as your body responds.

Disclaimer: This blog post is intended for educational purposes only and should not be taken as medical advice. Always consult your healthcare provider for personal health concerns.