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Hormone

Progesterone

Progesterone is produced by the ovaries after ovulation and by the adrenal glands. It prepares the uterine lining for implantation and supports pregnancy. Progesterone also promotes calm, sleep, and GABA activity.

Low progesterone relative to estrogen (estrogen dominance) can cause PMS, anxiety, and irregular cycles.

What It Measures

Serum progesterone levels, ideally tested mid-luteal phase (day 19–22).

Reference Ranges

StatusRange (ng/mL)
OptimalLuteal phase: 10–25 ng/mL
NormalPhase-dependent
BorderlineLuteal < 5 ng/mL
Out of RangeAnovulatory: < 1 ng/mL

Range by Cycle Phase

Cycle PhaseReference Range
Follicular< 1 ng/mL (days 1–13)
Ovulatory2–25 ng/mL (around ovulation)
Luteal5–20 ng/mL (days 17–28, peak 7 DPO)
Menopause< 1 ng/mL

Source: Endocrine Society, ACOG. Ranges are approximate — consult your provider.

When to test: Day 21 (or 7 days post-ovulation) for confirmation of ovulation.

Interpreting Your Results

When Values Are High

Confirms ovulation occurred. Very high may indicate molar pregnancy or congenital adrenal hyperplasia.

When Values Are Low

Anovulation, luteal phase defect, or impending miscarriage. Symptoms: irregular cycles, PMS, anxiety, insomnia.

How GATOR Tracks This

Lab Providers

Function HealthLabCorpQuest

Related Biomarkers

This content is for informational purposes only and does not constitute medical advice. Reference ranges may vary by laboratory and individual factors. Consult a qualified healthcare provider for interpretation of your results and treatment decisions.

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