| Hormone | Ref. Intervals | Constitution | Source/Target | Function |
| Thyrotropin-releasing hormone (TRH) | Baseline TSH: <10 m U/mL Stimulated TSH (following iv TRH): 2´ baseline | Peptide (3 aa)* | H/Anterior pituitary lobe | Release of TSH and PRL |
| Gonadotropin-releasing hormone (GnRH) or luteinizing hormone- releasing hormone (LHRH) | - | Peptide (10 aa) | H/Anterior pituitary lobe | Release of LH and FSH |
| Corticotropin-releasing hormone (CRH) | - | Polypeptide (41 aa) | H/Anterior pituitary lobe | Release of ACTH and ß-LPH |
| Growth hormone-releasing hormone (GHRH) | - | Polypeptide (40 aa) | H/Anterior pituitary lobe | Release of GH |
| Somatostatin± (SS) or growth hormone-inhibiting hormone (GHIH) | - | Peptide (14 aa) | H/Anterior pituitary lobe | Suppression of GH and TSH; inhibition of gastrin, VIP, GIP, secretin, motilin, and insulin |
| Prolactin-releasing factors (PRF) | - | Peptide? | H/Anterior pituitary lobe | Release of PRL |
| Prolactin-inhibiting factor (PIF) | 0 – 20 pg/mL (as dopamine) | Dopamine | H/Anterior pituitary lobe | Suppression of PRL |
| Thyrotropin or thyroid-stimulating hormone (TSH) | 40 – 200 mg/dL | Glycoprotein‡ (a , 89 aa; ß, 112 aa) | AP/Thyroid gland | Stimulation of thyroid hormone formation and secretion |
| Follicle-stimulating hormone (FSH) | Male: (<45 yr): 4 – 25 IU/L (³ 45 yr): 2 – 14 IU/L Female: (Non-preg, 18 – 40 yr): 4 – 30 IU/L (Midcycle): 10 – 90 IU/L (Postmenopausal): 40 – 250 IU/L | Glycoprotein‡ (a , 89 aa; ß, 115 aa) | AP/Ovary AP/Testis | Growth of follicles and, with LH, secretion of estrogens and ovulation. Development of seminiferous tubules, spermatogenesis |
| Luteinizing hormone (LH) | Female: (Non-preg, 18 – 40 yr): 1 – 9 IU/L (Midcycle): >11 IU/L (Postmenopausal): 13 – 60 IU/L Male: 6 – 23 IU/L | Glycoprotein‡ (a , 89 aa; ß, 115 aa) | AP/Ovary AP/Testis | Ovulation, formation of corpora lutea, secretion of progesterone. Stimulation of interstitial tissue; secretion of androgens. |
| Prolactin (PRL) | Female: 80 – 530 mIU/L Male: 80 – 350 mIU/L | Protein (198 aa) | AP/Mammary gland | Proliferation of mammary gland; initiation of milk secretion; antagonist of insulin action |
| Growth hormone (GH) or somatotropin | Female: 0 – 8.0 m g/L Male: 0 – 4.0 m g/L | Protein (191 aa) | AP/Body as a whole | Growth of bone and muscle |
| ß-Lipotropin (ß-LPH) | - | Polypeptide (91 aa) | AP/Unknown | Precursor of ß-MSH and the endorphins |
| Corticotropin or adrenocorticotropin (ACTH) | 1.2 – 15.6 pmol/L (ng/L = 4.5 ´ pmol/L) | Polypeptide (39 aa) | AP/Adrenal cortex | Stimulation of adrenocortical steroid formation and secretion |
| ß-Endorphin (ß-END)±¶ | 5 – 35 pmol/L | Polypeptide (31 aa) | AP/Brain | Endogenous opiate; raising of pain threshold and influence on extrapyramidal motor activity |
| a -Melanocyte-stimulating hormone (a -MSH) | - | Peptide (13 aa) | AP/Skin | Dispersion of pigment granules, darkening of skin |
| Leu-enkephalin (LEK)±¶ and met-enkephalin (MEK)±¶ | - | Peptide (5 aa) | AP/Brain | Endogenous opiate; raising of pain threshold and influence on extrapyramidal motor activity |
| Vasopressin or antidiuretic hormone (ADH) | 0.0 – 7.0 pmol/L | Peptide (9 aa) | PP/Arterioles PP/Renal tubules | Elevation of blood pressure. Water reabsorption |
| Oxytocin | <3.2 m IU/mL Oxytocin challenge test: Negative | Peptide (9 aa) | PP/Smooth muscle (uterus, mammary gland) | Contraction, action in parturition and in sperm transport, ejection of milk |
| Serotonin or 5-hydroxytryptamine (5-HI) | 5 – 220 ng/mL | Indoleamine | PG/Cardiovascular, respiratory, and gastrointestinal systems, brain | Neurotransmitter; stimulation or inhibition of various smooth muscles and nerves; possible role in mental illness |
| Melatonin | - | Indoleamine | PG/Hypothalamus | Suppression of gonadotropin and GH secretion; induction of sleep |
| Thyroxine (T4) and triiodothyronine (T3) (free T4, free T3) | T4: (<1 m): 0.8 – 2.2 ng/dL (1-6 m): 0.8 - 1.8 ng/dL (6m-1y): 0.8 – 1.6 ng/dL (1-12y): 0.9 – 1.4 ng/dL (>12 yr): 0.8 – 1.5 ng/dL T3: 2.2 – 4.0 pg/mL | Iodoamino acids | TG/General body tissue | Stimulation of oxygen consumption and metabolic rate of tissue |
| Calcitonin or thyrocalcitonin | <15 pmol/L | Polypeptide (32 aa) | TG/Skeleton | Inhibition of calcium resorption; lowering of plasma calcium and phosphate |
| Parathyroid hormone (PTH) or parathormone | 1.7 – 7.3 pmol/L | Polypeptide (84 aa) | PTG/Skeleton, kidney, gastrointestinal tract | Regulation of calcium and phosphorus metabolism |
| Cortisol | AM peak: 200 – 650 nmol/L PM trough: <50% peak | Steroid | AC/General body tissue | Metabolism of carbohydrates, proteins, and fats; inflammation, resistance to infection; hypersensitivity |
| Aldosterone | 100 – 800 pmol/L | Steroid | AC/Kidney | Salt and water balance |
| Norepinephrine and epinephrine | Epinephrine (pg/mL) 2-10 d: 36-400 11d-3m: 55-200 4-11mo: 55-440 12-23m: 36-640 24-35m: 18-440 3-17yr: 18-460 18+ yr: 10-200 Norepinephrine (pg/mL) 2-10 d: 170-1180 11d-3m: 370–2080 4-11mo: 270–1120 12-23m: 68–1810 24-35m: 170–1470 3-17yr: 85–1250 18+ yr: 80–520 | Aromatic amines | AM/Sympathetic receptors | Stimulation of sympathetic nervous system |
| Epinephrine | <570 pmol/L (see above) | Aromatic amine | AM/Liver and muscle, adipose tissue | Glycogenolysis Lipolysis |
| Estrogens | Female estradiol (pmol/L): Early follicular: 100 – 200 Preovulatory: 500 – 1700 Luteal: 500 – 900 Postmenopausal: 70 – 200 Male: 0 – 283 pmol/L Estriol: Varies with gestational age (increases thru pregnancy) | Phenolic steroids | O/Female accessory sex organs | Development of secondary sex characteristics |
| Progesterone | Female: (nmol/L) Follicular: 2.0 – 4.5 Luteal: 7.0 – 70.0 | Stroid | O/Female accessory reproductive structure | Preparation of the uterus for ovum implantation, maintenance of pregnancy |
| Relaxin | - | Polypeptide | O/Uterus | Inhibition of myometrial contraction |
| Inhibin | Female (>16 yr): 0 – 78 pg/mL | Polypeptide | O/Hypothalamus | Suspected role in the control of FSH secretion |
| Testosterone | Male: 300 – 1200 ng/dL Female: 30 – 95 ng/dL | Steroid | T/Male accessory sex organs | Development of secondary sex characteristics, maturation, and normal function |
| Inhibin | Female (>16 yr): 0 – 78 pg/mL | Polypeptide | T/Hypothalamus | Suspected role in the control of FSH secretion |
| Estrogens | Female estradiol (pmol/L): Early follicular: 100 – 200 Preovulatory: 500 – 1700 Luteal: 500 – 900 Postmenopausal: 70 – 200 Male: 0 – 283 pmol/L Estriol: Varies with gestational age (increases thru pregnancy) | Phenolic steroids | P/Female accessory sex organs | Development of secondary sex characteristics |
| Progesterone | Female: (nmol/L) Follicular: 2.0 – 4.5 Luteal: 7.0 – 70.0 | Steroid | P/Female accessory reproductive structure | Preparation of the uterus for ovum implantation, maintenance of pregnancy |
| Relaxin | - | Polypeptide | P/Uterus | Inhibition of myometrial contraction |
| Human chorionic gonadotropin (hCG) or choriogonadotropin | Female: (b -subunit) (Non-preg): <5 mIU/L | Glycoprotein‡ (a , 92 aa; ß, 144 aa) | P/Ovary AP/Testis | Ovulation, formation of corpora lutea, secretion of progesterone. Prolongation of corpus luteal function; suspected role in steroidogenesis during fetal life. Stimulation of interstitial tissue; secretion of androgens. |
| Human chorionic somatomammotropin (hCS) or human placental lactogen (hPL) | - | Protein (191 aa) | P/Mammary gland | Proliferation of mammary gland; initiation of milk secretion; antagonist of insulin action |
| Insulin, free | 9 – 80 pmol/L | Polypeptide§ | PAN/Most cells | Regulation of carbohydrate metabolism; lipogenesis |
| Glucagon | <190 ng/L | Polypeptide (29 aa) | PAN/Liver | Glycogenolysis |
| Pancreatic polypeptide (PP) | 40 – 300 ng/L (fasting) | Polypeptide (36 aa) | PAN/Gastrointestinal tract | Increased gut motility and gastric emptying; inhibition of gallbladder contraction |
| Gastrin¶ | Fasting: <90 ng/L Random: <180 ng/L | Peptide (17 aa) | GI/Stomach | Secretion of gastric acid, gastric mucosal growth |
| Secretin | 12 – 75 pg/mL | Polypeptide (27 aa) | GI/Pancreas | Secretion of pancreatic bicarbonate and digestive enzymes |
| Cholecystokinin-pancreozymin (CCK-PZ)¶ | - | Polypeptide (33 aa) | GI/Gallbladder and pancreas | Stimulation of gallbladder contraction and secretion of pancreatic enzymes |
| Motilin | - | Polypeptide (22 aa) | GI/Gastrointestinal tract | Stimulation of gastrointestinal motility |
| Vasoactive intestinal peptide (VIP)¶ | <20 pmol/L <50 pg/mL | Polypeptide (28 aa) | GI/Gastrointestinal tract | Neurotransmitter; relaxation of smooth muscles of gut and of circulation; increase of release of hormones and secretion of water and electrolytes from pancreas and gut |
| Gastric inhibitory polypeptide (GIP) | - | Polypeptide (42 aa) | GI/Gastrointestinal tract | Inhibition of gastric secretion and motility; increase of insulin secretion |
| Bombesin¶ | - | Peptide (14 aa) | GI/Gastrointestinal tract | Stimulation of release of various hormones and pancreatic enzymes, smooth muscle contractions and hypothermia, changes in cardiovascular and renal function |
| Neurotensin¶ | - | Peptide (13 aa) | GI/Gastrointestinal tract and hypothalamus (gut and brain) | Uncertain |
| Substance P (SP)¶ | - | Peptide (11 aa) | GI/Gastrointestinal tract and brain | Sensory neurotransmitter, analgesic; increase in contraction of gastrointestinal smooth muscle; potent vasoactive hormone; promotion of salivation, increased release of histamine |
| 1,25-(OH)2 Vitamin D | 22.5 – 94.3 nmol/L | Sterol | K/Intestine K/Bone K/Kidney | Facilitation of calcium and phosphorus absorption Increase in bone resorption in conjunction with PTH. Increase in reabsorption of filtered calcium |
| Erythropoietin | 12 – 28 U/L | Glycoprotein | K/Bone marrow | Stimulation of red cell formation |
| Insulin-like growth factor I | (ng/mL) 2m - 5y: 17 – 248 6 – 8 yr: 88 – 474 9-11 y Male: 110 – 565 9-11 y Fem: 117 – 771 12-15y Male: 202 – 957 12-15y Fem: 261 – 1096 16-24y M/F: 182 – 780 25-39y M/F: 114 – 492 40-54y M/F: 90 – 360 ³ 55 yr M/F: 71 – 290 | Peptide (70 aa) | L/Most cells | Stimulation of cellular and linear growth |
| Insulin-like growth factor II | - | Peptide (67 aa) | L/Most cells | Insulin-like activity |
| Thymosin and thymopoietin | - | Peptides (49 and 28 aa) | THY/Lymphocytes | Maturation of T-lymphocytes |
| Atrial natriuretic factor (Atrial natriuretic peptide, ANF, ANP, Atriopeptin) | 4 – 27 pmol/L | Peptide (28 aa) | HT/Vascular, renal, and adrenal tissue | Regulation of blood volume and blood pressure |
| Brain natriuretic factor (Brain natriuretic peptide, BNF, BNP) | 5 – 99 pg/mL | Peptide (17 aa) | HT/Vascular, brain tissue | Regulation of blood volume and blood pressure |
| Parathyroid hormone-related peptide (PTH-RP) | <5 pmol/L | Peptide (141 aa) | MCT/Kidney, bone | Conjectural; PTH-like actions; tumor marker |
| Growth factors (e.g., epidermal growth factor, fibroblast growth factor, transforming growth factor family, platelet-derived growth factor, nerve growth factors) | - | Polypeptides | MCT/ | Stimulation of cellular growth |
| Cytokines (e.g., interleukins 1 - 9, tumor necrosis factor, interferons) | - | Polypeptides | MLM/ | Stimulation or inhibition of cellular growth |
±Also produced by gastrointestinal tract.
‡Glycoprotein hormone composed of two dissimilar peptides. The a -chain is similar in structure or identical; the ß-chain differs for each hormone and confers specificity.
§Two chains linked by disulfide bonds: A, 21 aa; B, 30 aa.
¶Also produced in the brain.
>Source abbreviations: H = Hypothalamus, AP = Anterior Pituitary, PP = Posterior Pituitary, PG = Pineal Gland, TG = Thyroid Gland, PTG = Parathyroid Gland, AC = Adrenal Cortex, AM = Adrenal Mrdulla, O = Ovary, T = Testis, P = Placenta, PAN = Pancreas, GI = Gastrointestinal tract, K = Kidney, L = Liver, THY = Thymus, HT = Heart, MCT = Multiple Cell Types, MLM = Monocytes/Lymphocytes/Macrophages