When to Test Your Hormones: Complete Timing Guide

I can't tell you how many times a patient has sat down and said, "My doctor checked my hormones and everything's normal." Then I look at the labs and all I see is a TSH. That's it. One number. Checked at 3 PM on a random Tuesday. For a woman with irregular cycles, no cycle-day timing was considered. For a man complaining of fatigue and low libido, testosterone wasn't even ordered.

This drives me a little crazy, if I'm being honest. Because the difference between useful hormone testing and useless hormone testing often comes down to *when* the blood was drawn, *which* tests were ordered, and *how* the results are interpreted. Get any of those wrong, and you'll be falsely reassured that "everything's fine" when it isn't.

Hormone testing is one of the most powerful diagnostic tools in functional medicine — but only when done correctly. Timing, cycle day, time of day, and test type all dramatically affect the clinical utility of results. This guide gives you the practical knowledge to ensure your hormone testing is accurate and actionable.

Menstrual Cycle-Dependent Hormones (Women)

When to Test Estrogen and Progesterone

For menstruating women, hormones fluctuate dramatically across the cycle. Testing on the wrong day gives misleading results:

Day 3 (Follicular Phase):

• FSH (Follicle Stimulating Hormone): Assesses ovarian reserve
• LH (Luteinizing Hormone): Evaluates pituitary function
• Estradiol (E2): Baseline estrogen level
• Purpose: Evaluates ovarian function and fertility potential

Day 19–22 (Mid-Luteal Phase, ~7 days post-ovulation):

• Progesterone: MUST be tested mid-luteal to confirm ovulation and assess progesterone adequacy
• Estradiol: Evaluates luteal estrogen for hormonal balance
• Purpose: Confirms ovulation, assesses progesterone sufficiency, identifies luteal phase defect

For Irregular Cycles or PCOS

If cycles are irregular, standard cycle-day timing doesn't work. Options:

• Test on Day 3 if you can identify a clear menstrual onset
• Use the DUTCH test (dried urine) which captures hormone metabolites over 24 hours
• Track basal body temperature and ovulation predictor kits to identify ovulation, then test 7 days later

For Perimenopausal Women

Hormones fluctuate wildly in perimenopause, making single-point blood draws unreliable:

• The DUTCH test provides a more complete picture through metabolite mapping
• Test multiple months to identify patterns
• Clinical symptoms often outweigh lab numbers in perimenopause

Testosterone (Men and Women)

Men

• Time: Before 10 AM (fasting) — testosterone peaks in early morning and declines throughout the day
• Tests: Total testosterone, free testosterone, SHBG, estradiol, LH, FSH
• Frequency: Confirm with two separate morning draws if low
• Optimal ranges: Total T 600–900 ng/dL; free T 15–25 pg/mL (functional ranges, not lab "normal")

Women

• Time: Morning, Day 3 of cycle (or any morning if post-menopausal)
• Tests: Total and free testosterone, DHEA-S
• Elevated testosterone: Suggests PCOS, adrenal hyperplasia, or insulin resistance
• Low testosterone: Contributes to fatigue, low libido, muscle loss

Thyroid Panel

Thyroid testing is one of the most commonly mismanaged areas in conventional medicine:

• When: Morning, fasting (TSH is highest in early morning)
• Hold thyroid medication: If applicable, test before taking morning dose (to avoid false peaks)
• Complete panel: TSH, free T3, free T4, reverse T3, TPO antibodies, thyroglobulin antibodies
• TSH alone is insufficient — many patients have normal TSH with low free T3 or elevated antibodies

Optimal (Not Just "Normal") Ranges

• TSH: 1.0–2.0 μIU/mL (not the lab range of 0.5–4.5)
• Free T4: 1.1–1.5 ng/dL
• Free T3: 3.0–4.0 pg/mL
• Reverse T3: < 15 ng/dL
• TPO antibodies: < 9 IU/mL (any elevation suggests Hashimoto's)

Cortisol and Adrenal Function

The Right Test Matters

• Morning serum cortisol: Only captures one snapshot — limited utility
• 4-point salivary cortisol: Captures the diurnal curve (morning, noon, evening, bedtime) — much better
• DUTCH test: Most comprehensive — captures cortisol, cortisone, and metabolites over 24 hours
• When: The DUTCH test is collected at specific times (waking, +2 hours, afternoon, evening, bedtime)

What to Look For

• Healthy curve: High morning cortisol that declines throughout the day
• Flat curve: Suggests adrenal fatigue/HPA dysfunction or burnout
• Inverted curve: High evening cortisol — insomnia, anxiety pattern

Metabolic Hormones

Insulin

• When: Fasting (12-hour fast minimum)
• Test: Fasting insulin (NOT just fasting glucose)
• Optimal: < 5 μIU/mL (lab "normal" goes up to 24 — this misses early insulin resistance)
• Also order: HOMA-IR calculation, fasting glucose, HbA1c

Leptin and Ghrelin

• Fasting: Both should be tested in a fasted state
• Elevated leptin with obesity = leptin resistance (drives continued weight gain)