What is the normal progesterone (Progesterone) level for a 28-year-old female?

Normal Progesterone Levels in a 28-Year-Old Female

Normal progesterone levels for a 28-year-old female vary significantly depending on the phase of the menstrual cycle, with levels typically below 6 nmol/L during the follicular phase and rising to 10-15 times higher (approximately 12.4 nmol/L or higher) during the luteal phase. 1, 2

Menstrual Cycle Variations in Progesterone

Progesterone levels fluctuate predictably throughout the normal menstrual cycle:

Follicular Phase (Days 1-14 of a typical 28-day cycle)

• Range: 0.11-0.65 ng/mL (0.35-2.07 nmol/L)
• Levels remain relatively low and stable during this phase 2, 3

Ovulation/Mid-cycle

• Progesterone begins to rise immediately after the LH peak 3
• This marks the transition to the luteal phase

Luteal Phase (Days 15-28 of a typical 28-day cycle)

• Range: 8.6-19.9 ng/mL (27.3-63.2 nmol/L) at peak
• Reaches maximum concentration 5-8 days after the LH peak
• Typically peaks during the mid-luteal phase 2, 3
• Levels below 6 nmol/L during mid-luteal phase indicate anovulation 1

Interpretation of Progesterone Levels

When interpreting progesterone levels in a 28-year-old female, several important factors should be considered:

• Timing of measurement: The day of the menstrual cycle when the sample is collected is critical for proper interpretation 1
• Purpose of testing: Often measured during mid-luteal phase (approximately day 21 of a 28-day cycle) to confirm ovulation
• Laboratory variations: Reference ranges may vary between different laboratories 1

Clinical Significance

Abnormal progesterone levels may indicate:

1. Low mid-luteal progesterone (<6 nmol/L):

   • Anovulation
   • Polycystic ovary syndrome (PCOS)
   • Hyperprolactinemia
   • Hypothalamic amenorrhea 1

2. Consistently low progesterone:

   • Premature ovarian failure
   • Hypothalamic dysfunction
   • Potential fertility issues 1

Special Considerations

• Measurement method: Serum progesterone is the standard measurement method
• Diurnal variation: Minimal compared to other hormones, but morning measurements are preferred for consistency
• Medication effects: Hormonal contraceptives significantly alter natural progesterone levels and should be discontinued before testing 1
• Stress and exercise: Extreme physical stress or excessive exercise can affect progesterone production 1

Monitoring Recommendations

For women concerned about progesterone levels:

• Timing blood draws to coincide with the mid-luteal phase (approximately 7 days before expected menses)
• Serial measurements may be more informative than a single measurement
• Consider additional hormonal testing (LH, FSH, estradiol) for comprehensive evaluation if abnormalities are suspected 1

For accurate assessment of ovulatory function, the laboratory criteria of a normal ovulatory cycle include:

• Mid-cycle LH peak
• Luteal phase progesterone levels 10-15 times higher than follicular phase
• Progesterone peak occurring at mid-luteal phase
• Luteal phase duration of 12-15 days 2