Evidence-Based Supplement & Herb Guides

Human Placental Lactogen (hPL) Test: Placenta Function, Pregnancy Hormone, and Results

Learn what human placental lactogen does, why hPL testing is uncommon, what low or high results may mean, and how placental function is assessed in pregnancy.

Human placental lactogen, or hPL, is a protein hormone made by the placenta that helps shift maternal metabolism so the fetus has a steady...

Inhibin A Test in Pregnancy: Quad Screen, Down Syndrome Risk, and Results

Understand inhibin A in the quad screen, MoM values, high results, Down syndrome risk calculations, placental associations, and follow-up testing options.

Inhibin A is a placental and ovarian protein measured in maternal blood as one part of the second-trimester quad screen. The laboratory combines inhibin...

Miscarriage Hormone Test Panel: hCG, Progesterone, and Pregnancy Loss Results

Understand hCG and progesterone testing for suspected miscarriage, common result patterns, ultrasound follow-up, treatment limits, and urgent ectopic warning signs.

A miscarriage hormone panel usually means quantitative hCG testing, sometimes combined with progesterone, during an early pregnancy with bleeding, pain, uncertain development, or an...

Pregnancy Hormone Test Panel: hCG, Progesterone, Estradiol, Estriol, and Results

Understand hCG, progesterone, estradiol, and estriol pregnancy tests, what results can show, treatment effects, and when ultrasound or other testing is more useful.

A pregnancy hormone panel may include hCG, progesterone, estradiol, and estriol, but these tests answer different questions and are not routinely ordered together in...

Pregnancy-Associated Plasma Protein A (PAPP-A) Test: First-Trimester Screening and Results

Understand PAPP-A first-trimester screening, MoM values, low and high results, trisomy risk, placental associations, and appropriate follow-up.

Pregnancy-associated plasma protein A, or PAPP-A, is a protein produced largely by the placenta and measured in maternal blood during first-trimester screening. Laboratories combine...

Progesterone Test in Pregnancy: Low Levels, Miscarriage Risk, and Results

Understand progesterone testing in pregnancy, including low levels, miscarriage risk, result ranges, supplementation, and how hCG and ultrasound guide follow-up.

A progesterone blood test measures a hormone that helps prepare the uterine lining, support implantation, and maintain early pregnancy. The corpus luteum produces most...

Quad Screen Test: AFP, hCG, Estriol, Inhibin A, and Pregnancy Results

Learn how the quad screen uses AFP, hCG, estriol, and inhibin A, what positive pregnancy results mean, and which ultrasound or diagnostic follow-up may be offered.

The quad screen is a second-trimester maternal blood test that estimates the chance of certain fetal chromosome conditions and open neural tube defects. It...

Qualitative hCG Blood Test: Positive, Negative, Pregnancy, and Results

Understand qualitative hCG blood test results, including positive, negative, borderline, early pregnancy timing, false results, and when quantitative testing is needed.

A qualitative hCG blood test answers a focused question: is human chorionic gonadotropin detected above the assay’s decision threshold? The report is usually “positive”...

Quantitative hCG Blood Test: Pregnancy Levels, Doubling Time, and Results

Understand quantitative hCG blood test levels, expected rises, doubling time, falling results, ultrasound timing, and follow-up for early pregnancy and ectopic risk.

A quantitative hCG blood test measures the concentration of human chorionic gonadotropin in serum and reports a number, usually in milli-international units per milliliter....

Relaxin Blood Test: Pregnancy Hormone, Pelvic Changes, and Results

Learn what a relaxin blood test measures in pregnancy, why routine testing is uncommon, how pelvic changes are assessed, and what low or high research results may mean.

Relaxin is a peptide hormone produced mainly by the corpus luteum during human pregnancy, with additional local production reported in reproductive tissues. It participates...

Acromegaly Blood Test Panel: IGF-1, Growth Hormone, Oral Glucose Suppression, and Results

Understand acromegaly blood testing, including IGF-1, random growth hormone, oral glucose suppression, result patterns, confounders, and follow-up steps.

Acromegaly blood testing looks for persistent overactivity of the growth hormone system. The usual first test is insulin-like growth factor 1, or IGF-1, because...

ACTH Blood Test: High, Low, Pituitary Function, and Adrenal Results

Learn how an ACTH blood test is interpreted with cortisol, including high and low patterns, pituitary and adrenal causes, preparation, follow-up tests, and urgent symptoms.

An adrenocorticotropic hormone, or ACTH, blood test measures the pituitary signal that tells the adrenal glands to make cortisol. The result is most useful...

Antidiuretic Hormone (ADH) Test: Water Balance, Diabetes Insipidus, and Results

Understand ADH blood testing for water balance, including low and high vasopressin patterns, diabetes insipidus, osmolality, copeptin, collection limits, and next steps.

An antidiuretic hormone blood test measures arginine vasopressin, the hormone that helps the kidneys conserve water. ADH and vasopressin are two names for the...

Central Hypothyroidism Test Panel: TSH, Free T4, Pituitary Function, and Results

Learn how a central hypothyroidism panel uses free T4, TSH, cortisol, other pituitary hormones, and imaging to diagnose and monitor pituitary-related thyroid deficiency.

Central hypothyroidism occurs when the hypothalamus or pituitary does not stimulate a structurally normal thyroid gland well enough to produce adequate thyroid hormone. The...

Copeptin Blood Test: ADH Surrogate Marker, Diabetes Insipidus, and Results

Understand how a copeptin blood test serves as an ADH surrogate, how baseline and stimulated results distinguish diabetes insipidus from primary polydipsia, and what can affect interpretation.

A copeptin blood test helps evaluate the body’s vasopressin system when excessive thirst, excessive urination, abnormal sodium, or a suspected water-balance disorder needs clarification....

Diabetes Insipidus Hormone Test Panel: Copeptin, ADH, Serum Osmolality, Urine Osmolality, and Results

Learn how a diabetes insipidus test panel combines copeptin, ADH, serum sodium, plasma osmolality, urine osmolality, and dynamic testing to identify water-balance disorders.

A diabetes insipidus hormone test panel evaluates whether excessive urine output comes from inadequate vasopressin release, kidney resistance to vasopressin, excessive water intake, or...

Follicle-Stimulating Hormone (FSH) Test: Pituitary Function, Fertility, and Results

Learn how an FSH blood test reflects pituitary and gonadal function, what high or low results can mean, how cycle timing affects ranges, and why fertility interpretation requires related tests.

A follicle-stimulating hormone test measures FSH, a pituitary hormone that helps regulate ovarian follicle development, estradiol production, sperm production, puberty, and reproductive function. The...

Growth Failure Hormone Test Panel: IGF-1, IGFBP-3, GH Stimulation, and Results

Learn how a pediatric growth failure panel combines growth velocity, IGF-1, IGFBP-3, GH stimulation, bone age, and pituitary evaluation to distinguish GH deficiency from other causes.

A growth failure hormone test panel evaluates whether a child’s slow height gain may involve the growth hormone–IGF-1 axis. The panel usually includes insulin-like...

Growth Hormone (GH) Test: High, Low, Normal Range, and Results

Learn why random GH levels are difficult to interpret, how stimulation and suppression tests define low or high growth hormone, and which age-, assay-, and protocol-specific results guide diagnosis.

A growth hormone blood test measures GH, also called somatotropin, but a single result rarely answers whether production is normal. GH is released by...

Growth Hormone Stimulation Test: GH Deficiency, Peak Levels, and Results

Learn how a growth hormone stimulation test measures GH reserve, how insulin, glucagon, arginine, clonidine, and macimorelin protocols differ, and how peak levels are interpreted.

A growth hormone stimulation test evaluates whether the pituitary can release an adequate GH surge when challenged. It is used when a child has...