What Are the Six Key Hormone Tests in Endocrine Screening?

When it comes to evaluating hormonal health, the so-called "six endocrine tests" typically refer to a panel of sex hormone assessments. These include estradiol (a primary form of estrogen), progesterone, testosterone (the main androgen), as well as three hormones produced by the pituitary gland: follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin. Together, these markers offer crucial insights into the body's endocrine balance, particularly reproductive health.

Why These Hormones Matter

Each of the six hormones plays a distinct role in regulating bodily functions:

Estradiol

Estradiol is the most potent estrogen and is essential for menstrual cycle regulation, fertility, and maintaining bone and cardiovascular health in women. Abnormal levels may indicate ovarian dysfunction, menopause, or even certain tumors.

Progesterone

Progesterone supports pregnancy and prepares the uterine lining for implantation. It's commonly tested mid-cycle to confirm ovulation and assess luteal phase adequacy.

Testosterone

While often associated with males, testosterone is also present in women and contributes to libido, energy levels, and muscle mass. Elevated levels in women could signal polycystic ovary syndrome (PCOS) or adrenal disorders.

Follicle-Stimulating Hormone (FSH)

FSH stimulates ovarian follicle growth in women and sperm production in men. High FSH levels may point to diminished ovarian reserve or testicular failure.

Luteinizing Hormone (LH)

LH triggers ovulation and promotes progesterone production. An abnormal LH-to-FSH ratio is often seen in PCOS patients.

Prolactin

Prolactin regulates milk production post-childbirth. Elevated levels (hyperprolactinemia) can disrupt menstrual cycles and cause infertility in both sexes.

Expanding to Seven: When hCG Is Added

For women of reproductive age who have missed their period, healthcare providers often recommend adding human chorionic gonadotropin (hCG) to the panel—making it a "seven-hormone test." This hormone is a key indicator of pregnancy and helps rule out or confirm gestational status when interpreting other hormonal imbalances.

Optimal Timing for Testing

For Women: To accurately assess ovarian function, blood tests should ideally be performed on days 2–4 of the menstrual cycle. This early follicular phase provides the most reliable baseline for FSH, LH, and estradiol levels, offering a clear picture of reproductive potential.

For Men: While less common, this panel can also help diagnose male hypogonadism, infertility, or pituitary disorders. Testing can be done at any time, though morning appointments are preferred due to natural diurnal hormone fluctuations.

Clinical Applications Beyond Fertility

These hormone panels are not only useful for fertility evaluations but also aid in diagnosing conditions such as PCOS, premature ovarian failure, hypothalamic amenorrhea, pituitary tumors, and adrenal gland abnormalities. Early detection through comprehensive hormone testing empowers both patients and physicians to develop targeted treatment plans.

Whether you're investigating irregular periods, unexplained infertility, low libido, or hormonal imbalances, the six (or seven) endocrine tests serve as a foundational tool in modern endocrinology—offering clarity, guiding therapy, and improving long-term health outcomes.