Hormones such as Anti-Mullerian hormone (AMH), Thyroid-stimulating hormone (TSH) and Prolactin (Prl) can be tested any day during your cycle. However, some hormones such as Follicle-stimulating hormone (FSH), Luteinising hormone (LH), and Oestradiol (E2) fluctuate throughout your cycle.
Since different hormones fluctuate throughout your cycle, if you are not on hormonal contraception, you must collect your sample on day 3 of your menstrual cycle. This is when your fluctuating hormones are at a baseline and therefore we get the most accurate results.
It’s also best to test in the morning, within 3-4 hours of waking up after fasting for at least 8 hours. Some hormones also fluctuate throughout the day - so collecting your sample first thing gives the most accurate readings.