Blood draw timing significantly affects hormone result accuracy. Each hormone has an ideal testing day.
Timing by Hormone:
- FSH, LH, Estrogen: Day 2-3 of cycle (first day of bleeding = day 1). Best morning fasting.
- Progesterone: Day 21 of cycle (or 7 days after expected ovulation). Evaluates whether ovulation occurred.
- Prolactin: Any day — but morning fasting after rest (stress raises it). Avoid testing after breast exam.
- TSH (Thyroid): Any day — best morning.
- Testosterone and DHEAS: Day 2-3 morning.
- AMH (Ovarian reserve): Any day of cycle — not affected by timing.
Pre-Test Tips:
- Fast 8-12 hours for morning tests.
- Stop biotin 48 hours before (affects results).
- Tell doctor about any hormonal medications.
- Avoid physical exertion and stress before testing.
At BEIT TARIQ Center, we coordinate optimal timing for your blood draw to obtain accurate, reliable results.