Hormone Blood Tests: What to Order, When, and What Results Mean

Hormones are chemical messengers that govern nearly every process in your body — from metabolism and energy to reproduction, mood, and sleep. Yet "you should get your hormones checked" is one of the vaguest pieces of advice in medicine. Which hormones? When? And what do the numbers actually mean?

This guide organizes the world of hormone blood tests into clear, practical sections: thyroid, sex hormones, adrenal, and metabolic. For each group, you will learn what to order, when to test, what normal ranges look like, and when to see a specialist.

Disclaimer: This information is for educational purposes only and does not replace professional medical advice. Always consult an endocrinologist or your primary care provider for diagnosis and treatment.

Why Test Hormones?

Hormones are produced by endocrine glands — the thyroid, adrenals, pituitary, gonads (ovaries and testes), and pancreas. They regulate metabolism, growth, reproduction, stress response, appetite, sleep, and body temperature.

Common reasons to order hormone tests:

• Chronic fatigue, sluggishness, unexplained weight gain — most often thyroid.
• Hair loss, brittle nails, dry skin — thyroid plus ferritin plus vitamin D.
• Irregular periods, difficulty conceiving, severe PMS — sex hormones.
• Low libido, erectile dysfunction, abdominal weight gain in men — testosterone, estradiol, SHBG.
• Chronic stress, anxiety, poor sleep, central fat accumulation — cortisol.
• Suspected pregnancy — hCG.
• Excessive thirst, frequent urination, hunger after meals — insulin and glucose.

Hormone testing is not done "just in case" — it is always tied to a specific complaint, clinical question, or goal such as pregnancy planning or treatment monitoring.

Thyroid Hormones

The thyroid is the master regulator of metabolism. Its hormones determine how fast your body burns energy, maintains temperature, and responds to physical demands. Thyroid disorders are among the most common endocrine conditions, particularly in women over 40.

TSH: The Master Switch

TSH (thyroid-stimulating hormone) is produced by the pituitary gland and commands the thyroid to produce hormones. It works as an inverse marker: the higher the TSH, the harder the pituitary is pushing because the thyroid is underperforming.

Normal TSH: 0.4-4.0 mIU/L (upper limit varies slightly by lab).

• TSH above 4.0 — hypothyroidism (overt or subclinical). More common than most people realize, especially in women over 40.
• TSH below 0.4 — hyperthyroidism (thyrotoxicosis).
• During pregnancy, TSH norms are lower (first trimester: up to 2.5 mIU/L).

For the full breakdown of thyroid test interpretation, see our thyroid test results guide.

Free T4, Free T3, and Antibodies

If TSH is abnormal, your provider typically orders:

• Free T4 (thyroxine) — the primary thyroid hormone in circulation. Normal: 0.8-1.8 ng/dL.
• Free T3 (triiodothyronine) — the most biologically active form. Normal: 2.3-4.2 pg/mL. Sometimes drops before T4 does.
• TPO antibodies (anti-thyroid peroxidase) — the hallmark of Hashimoto thyroiditis, the most common cause of hypothyroidism worldwide. Elevated levels almost always indicate autoimmune thyroid disease.
• Thyroglobulin antibodies — less commonly informative than TPO antibodies.

The Hidden Impact of Thyroid Dysfunction

Thyroid disorders can masquerade as seemingly unrelated conditions:

• Unexplained fatigue — always check TSH.
• Hair loss — TSH plus free T4.
• Inability to lose weight — thyroid dysfunction blocks fat burning when TSH is elevated.
• Insomnia — hyperthyroidism can cause persistent sleep disruption.

Sex Hormones

Sex hormone testing is the most frequently requested — and the most commonly misinterpreted — hormonal workup. In women, results are highly dependent on the day of the menstrual cycle. In men, timing of the draw (morning vs. afternoon) matters significantly.

Female Sex Hormones

Cycle day 1 is the first day of full menstrual bleeding — not spotting the day before.

For women planning pregnancy, these tests are part of the preconception blood test panel.

Male Sex Hormones

Testosterone levels are highest in the morning and can drop 20-30% by afternoon. Always draw before 10:00 AM for accurate results.

For men planning to conceive, see preconception tests for men.

Adrenal Hormones

Cortisol: The Stress Hormone

Cortisol is produced by the adrenal glands and follows a strong circadian rhythm — highest at 8:00 AM, lowest around midnight.

Normal morning cortisol (8:00-9:00 AM): 5-25 mcg/dL (138-690 nmol/L).

• Elevated morning cortisol — acute or chronic stress, Cushing syndrome (rare).
• Low morning cortisol — adrenal fatigue after prolonged stress, Addison disease (very rare).
• Elevated evening cortisol — disrupted circadian rhythm, chronic insomnia, obesity.

For suspected circadian disruption, providers may order a 4-point salivary cortisol test throughout the day. Not all labs offer this option.

DHEA-S: Adrenal Androgens

Dehydroepiandrosterone sulfate is the primary adrenal androgen. Normal values depend on age and sex (levels naturally decline after age 30).

Elevated DHEA-S in a woman combined with hair loss, acne, and weight gain raises suspicion for adrenal hyperandrogenism and warrants endocrinology evaluation.

Insulin and Metabolic Hormones

Insulin and HOMA-IR: Insulin Resistance

Insulin regulates blood sugar. In insulin resistance, cells respond poorly to insulin, so the body produces more — driving fat storage and making weight loss extremely difficult.

What to order (strictly fasting, 8-12 hours):

• Fasting glucose — normal 70-99 mg/dL.
• Fasting insulin — normal 2.7-10.4 mcIU/mL (varies by lab).
• HOMA-IR — calculated as (glucose in mmol/L x insulin in mcIU/mL) / 22.5.

Normal HOMA-IR: below 2.7. Above 4.0: overt insulin resistance.

High insulin effectively locks fat-burning pathways. When HOMA-IR exceeds 3.0, standard calorie-deficit diets often fail because the hormonal environment overrides the energy balance. This is part of diabetes monitoring blood tests and a core component of pre-weight-loss testing.

Leptin and Ghrelin

Rarely ordered in routine practice. Leptin is produced by fat tissue and signals satiety to the brain; in obesity, leptin resistance often develops. Ghrelin is the hunger hormone. These may be useful in complex cases of refractory obesity but are not part of standard panels.

How to Prepare for Hormone Tests

Proper preparation is non-negotiable for accurate hormone results:

1. Morning draw, fasting, 7:00-10:00 AM. Most hormones follow a circadian rhythm.
2. No intense exercise for 24 hours before the test.
3. No alcohol for 48 hours.
4. Rest before the draw — sit quietly for 15 minutes. Cortisol and prolactin are especially stress-sensitive.
5. No smoking for at least 1 hour before.
6. For women — test on the correct cycle day (when applicable).
7. Do not take morning medications before the draw (especially levothyroxine, oral contraceptives, or statins) — but never discontinue medications without discussing with your doctor first.
8. Consistency — retest at the same lab, same time of day, same cycle phase. Otherwise, comparisons are meaningless.

How to Interpret Hormone Results

The central challenge with hormones is that combinations matter more than individual values. Examples:

• TSH 5.5 + normal free T4 = subclinical hypothyroidism — check TPO antibodies.
• Testosterone "in range" in a man, but SHBG is high = bioavailable testosterone is actually low.
• FSH above 25 in a 38-year-old woman = early decline of ovarian reserve.
• Progesterone "normal" on day 21, but basal body temperature stays low = possible issue in a different part of the axis.
• Normal DHEA-S but elevated free testosterone + irregular cycles = PCOS pattern, not adrenal.

A single isolated value rarely tells the full story. Context is everything: sex, age, cycle phase, symptoms, medications, body composition, and lifestyle.

When to See a Specialist

Consult an endocrinologist or relevant specialist if:

• TSH above 4.0 or below 0.4 — thyroid dysfunction confirmed.
• Total testosterone in a man below 300 ng/dL with symptoms — discuss hypogonadism.
• Irregular cycles in a woman with multiple abnormal sex hormone values — gynecologist-endocrinologist.
• Signs of PCOS (irregular cycles, acne, weight gain, elevated LH or testosterone).
• HOMA-IR above 3.0 with excess weight — endocrinologist for insulin resistance.
• Cortisol markedly elevated or suppressed with symptoms — rule out Cushing or Addison.
• Infertility lasting more than 12 months — comprehensive hormonal workup by a reproductive endocrinologist.

Do not attempt to correct hormones on your own with supplements, unregulated compounds, or iodine without a confirmed deficiency. The endocrine system is the most sensitive to well-intentioned errors, and the potential for harm is real.

Related Tests

Hormone panels rarely exist in isolation. Depending on your results and symptoms, your provider may also recommend:

• Complete blood count — anemia often coexists with thyroid and iron deficiency.
• Blood chemistry panel — liver and kidney function affect hormone metabolism.
• Urinalysis — kidney function impacts electrolyte and hormone clearance.

Get Your Results Interpreted

Hormone tests can be confusing — especially when multiple values need to be read together in the context of your age, sex, and cycle phase. If you have a hormone panel and want a clear explanation of what your results mean, upload your results at Evallume for an instant AI-powered interpretation that connects the dots across all your values.

This article is for informational purposes only. It does not constitute medical advice, diagnosis, or treatment. Consult a healthcare professional for any medical concerns.