Is a Total Estrogen Level of 76 pg/mL Normal for a 21-Year-Old?
Yes, a total estrogen level of 76 pg/mL is normal for a 21-year-old premenopausal woman, falling within the expected follicular phase range (51-601 pg/mL) provided by the laboratory reference intervals.
Understanding the Result in Context
The reported value of 76 pg/mL sits comfortably within the follicular phase reference range of 51-601 pg/mL 1. This level is physiologically appropriate for a young premenopausal woman and does not warrant concern or further investigation based on the value alone.
Key Interpretive Points
Menstrual cycle timing matters significantly: Estrogen levels fluctuate dramatically throughout the menstrual cycle, ranging from follicular phase lows to mid-cycle peaks approaching 600 pg/mL, then rising again during the luteal phase (87-1194 pg/mL) 2.
This level is well above the threshold for concern: Estradiol levels below 20 pg/mL in premenopausal women should prompt investigation for functional hypothalamic amenorrhea or premature ovarian insufficiency, but 76 pg/mL is nearly 4 times this threshold 1, 3.
The level indicates normal ovarian function: Research using highly sensitive LC-MS/MS methodology confirms that premenopausal women typically have estradiol levels ranging from undetectable to 100 pmol/L (approximately 27 pg/mL) during early follicular phase, with levels increasing substantially during the cycle 2.
When to Investigate Further
Clinical context supersedes the numeric value. Further workup would only be indicated if this patient presents with 4, 3:
- Menstrual irregularities: Amenorrhea >6 months, oligomenorrhea (cycles >35 days), or polymenorrhea (cycles <23 days)
- Infertility: Inability to conceive after 12 months of unprotected intercourse
- Signs of hyperandrogenism: Hirsutism, acne, male-pattern hair distribution
- Galactorrhea or symptoms of hyperprolactinemia
- Symptoms of estrogen deficiency: Hot flashes, vaginal dryness, bone pain
Common Pitfall to Avoid
Do not interpret a single estrogen measurement in isolation without knowing cycle timing 2. A level of 76 pg/mL could represent early follicular phase (normal), mid-follicular phase (normal), or even a suppressed state if measured during what should be the ovulatory surge. Always correlate with menstrual history and, if needed, repeat testing with FSH and LH at specific cycle days (day 3-6) to properly assess ovarian reserve and function 4, 3.