Skip to content

Serum Progesterone Level (15-day Cycle Phase)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of progesterone hormone in your blood, specifically taken during the mid-luteal phase of your menstrual cycle (around day 15 of a typical 28-day cycle). Progesterone helps regulate your menstrual cycle and supports pregnancy.

Quick summary

["Progesterone levels help assess fertility, ovulation timing, and potential hormonal imbalances."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
17485-4
Short code
Progest 15M p chal SerPl-mCnc
Synonyms
Progest 15M p chal SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you’re trying to conceive, experiencing irregular periods, suspecting an ovarian cyst, or evaluating symptoms like heavy bleeding, pain, or hormonal imbalances. It can also help diagnose conditions like polycystic ovary syndrome (PCOS) or evaluate fertility treatments.

What to Expect Before the Test

For this test, you’ll provide a blood sample drawn from a vein in your arm. No special preparation is needed, but your provider may ask you to confirm your cycle day (typically day 15). Avoid alcohol or certain medications that could affect results for 24 hours before testing.

What the Results Mean

Progesterone levels vary by cycle phase. Low levels may indicate issues with ovulation or luteal phase deficiency, while very high levels could suggest conditions like ovarian tumors. Your results will be compared to your individual baseline and clinical context, not a single reference range.

Common Conditions Linked to Progesterone Testing

Abnormal progesterone levels can signal fertility problems, hormonal disorders, or complications like miscarriage risk. In pregnancy, low progesterone may signal early pregnancy loss, while high levels could warrant further evaluation for conditions like ovarian hyperstimulation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Frequently asked questions

How long does it take to get my results back?
Results are typically available within 24–72 hours, depending on your lab. Follow up with your provider to discuss findings and next steps.
Can I take anything for my progesterone levels?
Avoid alcohol and medications that alter hormone levels (e.g., birth control pills, steroids) for 24 hours before testing. Always check with your provider first.
Does this test require fasting?
No fasting is required for this blood test. However, your provider may ask you to confirm your cycle day to ensure accurate timing.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy