Progesterone — Luteal-Phase Confirmation
Progesterone rises after ovulation. A mid-luteal draw above 10 ng/mL confirms it happened; below that points to anovulation or a luteal-phase defect. The cycle day of the draw decides whether the number means anything.
Progesterone rises sharply after ovulation, so a mid-luteal draw — roughly day 21 of a 28-day cycle — above 10 ng/mL confirms that ovulation happened, while a result below that threshold points to anovulation or a luteal-phase defect.
The biomarker
- Name: Progesterone (Luteal, Women)
- Units: ng/mL
- Standard reference range: follicular < 1; luteal 2–25; post-menopause < 0.5
- Optimal range: > 10 (mid-luteal)
How to read your result
| Value | Interpretation |
|---|---|
| 10–25 ng/mL | Healthy luteal phase |
| < 10 ng/mL (mid-luteal) | Likely anovulation or luteal defect |
| > 2 ng/mL (follicular) | Investigate — rare |
| Post-menopause | < 0.5 ng/mL expected |
The cycle day of the draw decides whether the number means anything at all. A luteal-range result taken in the follicular phase reads as abnormal; a follicular-range result taken mid-luteal reads as a missed ovulation. Record the day.
What moves the needle
- Timing the draw. Cycle day at the draw is critical — mid-luteal means roughly seven days after ovulation, not seven days before the next period if cycles are irregular.
- Adequate calories and fat. Sustained energy deficit and very low fat intake suppress the luteal phase.
- Training and sleep load. Reducing training volume and sleep debt removes two of the most common suppressors of ovulation in active women.
- Clinician referral. An OB/GYN is the right next step if cycles are irregular — this test describes the cycle, it does not explain why.
Why this test is worth asking for
- It is the practical confirmation that ovulation occurred. Cycle tracking apps and basal temperature charts infer ovulation; a mid-luteal progesterone measures its downstream product.
- A luteal-phase defect can sit behind short cycles, spotting, and difficulty conceiving while every other panel looks unremarkable.
- It pairs naturally with estradiol: estradiol describes the follicular half of the cycle, progesterone the luteal half.
Related protocols
- Zinc — Immune + Hormone Cofactor
- TSH, Free T3 and T4 — Thyroid Panel
- Testosterone, Total and Free (Men)
Sources
AgeGen lab guides are educational only. We do not provide medical diagnosis, prescribe brands, or recommend specific doses. Talk to a licensed clinician before changing your supplement or medication routine.
