Hormones and signaling molecules

Signaling molecules from fat tissue, including leptin, adiponectin, resistin, and inflammatory cytokines, connect the amount and state of fat with appetite, insulin resistance, inflammation, and vascular risk.

This fat-tissue adipokine is linked with better insulin sensitivity, fatty acid oxidation, and a calmer inflammatory profile; levels often fall with visceral obesity.

This acute adrenal catecholamine rapidly mobilizes glucose and fatty acids, raises heart rate, and prepares the body for action; chronic anxiety and sleep loss can turn this useful emergency signal into a burden.

A group of steroid hormones that define male traits, influence strength, endurance, and sexual desire, but are also important for the female body. The main androgen is testosterone.

A group of steroid hormones synthesized by the adrenal cortex from cholesterol. They are a key link in the body's adaptation to stress, regulating energy metabolism, inflammatory responses, immune activity, and water-electrolyte balance.

This adrenal cortex hormone helps maintain blood pressure, glucose, wakefulness and anti-inflammatory control, but it should not be interpreted as a simple “stress hormone.” Timing, circadian rhythm, sleep, illness, medications, training, energy deficit and the reason for testing all matter; one value without context is weak evidence.

A neurotransmitter belonging to the catecholamine group, which is involved in the transmission of signals between nerve cells and plays a key role in regulating motivation, pleasure, motor activity, and cognitive processes.

High prolactin may accompany ovulation problems, cycle instability, breast tenderness, reduced libido, and infertility, but it should be interpreted only together with stress, sleep, thyroid function, medications, and cycle timing.

Are a group of endogenous opioid neuropeptides that are synthesized in the central nervous system and play a key role in regulating pain, stress, and emotional state. Their main function — is to adapt the body to physical and psycho-emotional loads.

A group of sex hormones influencing the cycle, bones, vessels, brain, skin, fat tissue, fertility, and metabolism; context matters as much as the level.

FSH is a gonadotropic hormone produced by the pituitary gland that regulates follicle maturation in women and supports spermatogenesis in men, which is why it is evaluated in the context of fertility, cycle, and gonadal function. It cannot be interpreted by a single number: its value depends on sex, age, cycle phase, menopause, and neighboring hormones, primarily LH, estradiol, testosterone, and inhibin.

The main inhibitory neurotransmitter in the central nervous system. GABA helps limit excessive neuronal excitation, but its function depends on glutamate balance, sleep, magnesium, vitamin B6, stress, medication and brain health.

The hunger hormone is produced mainly in the stomach and helps the brain track meal timing, energy availability, gut motility and food motivation. Its level is shaped by sleep, stress, habitual meal patterns, calorie deficit, protein intake and diet quality.

A hormone from pancreatic alpha cells that helps maintain glucose between meals by activating hepatic glycogen breakdown and gluconeogenesis.

A group of hormones and medications with strong effects on inflammation, immunity, glucose and protein metabolism; its practical meaning depends on symptoms, tests and the wider metabolic context.

Somatotropin regulates tissue growth, recovery, lipolysis, glucose metabolism and the IGF-1 system, but it should not be treated as a simple youth hormone. Levels are shaped by sleep, nutrition, training, age, pituitary disease, insulin resistance and medications.

A biogenic amine involved in the regulation of immune, nervous, and digestive processes. It is synthesized in the body from the amino acid histidine and is predominantly stored in mast cells and basophils, as well as present in neurons and stomach cells.

The body’s ability to keep its internal environment within working limits underlies regulation of glucose, temperature, acidity, blood pressure, electrolytes and fluid balance. Nutrition can support these mechanisms, but it does not replace nervous, hormonal, kidney, respiratory and immune regulation.

(HRT) is a medical approach aimed at replenishing hormone deficiencies that arise due to age-related changes, endocrine system diseases, or surgical removal of hormone-producing organs. The decrease in sex hormone levels significantly affects metabolism, fat distribution, bone and muscle condition, as well as the body's energy balance.

Gut hormones released in response to food that coordinate the stomach, pancreas, liver, appetite and glucose control. The main incretins are GLP-1 and GIP; their effects depend on meal composition, insulin sensitivity and medications.

A pancreatic hormone that regulates glucose, energy storage and use, protein synthesis, lipolysis and liver metabolism. It is not an enemy by itself; problems arise with deficiency, excess, insulin resistance or inappropriate therapy.

The insulin response to a specific meal depends not only on carbohydrates, but also on protein, fat content, digestion speed, time of day, sleep, stress and metabolic health. In LCHF, the goal is not zero insulin, but a predictable and appropriate post-meal response.

This fat-tissue hormone informs the brain about energy stores and helps regulate appetite, energy expenditure, reproductive function, thyroid signaling and immune responses. In obesity leptin is usually high, but the signal may be poorly perceived; improving leptin sensitivity through sleep, visceral fat loss, sustainable diet and recovery matters more than trying to “add leptin.”

A neurotransmitter and stress-response hormone that affects wakefulness, attention, vascular tone, blood pressure, glucose mobilization and threat response. It should not be reduced to motivation or anxiety; sleep, glucose, thyroid status, medications and the nervous system all matter.

A hormone and neuropeptide involved in labor, lactation, attachment, social regulation, stress and pain sensitivity. It should not be reduced to a “love hormone”; its effects depend on context, receptors, safety and nervous-system state.

This pancreatic hormone helps coordinate digestion, appetite signaling, bile flow, and exocrine pancreatic activity. It is not a lifestyle marker to optimize on its own; it becomes clinically relevant mainly in narrow contexts such as rare pancreatic neuroendocrine tumors or complex pancreatic disease assessment.

A steroid hormone primarily produced by the corpus luteum of the ovaries after ovulation, and to a lesser extent — by the adrenal glands and placenta during pregnancy. It plays a key role in maintaining women's reproductive health, but also affects metabolism, the nervous system, and the balance of other hormones.

A peptide hormone produced by the anterior pituitary gland, traditionally associated with lactation; however, its functions are much broader. It plays a role in regulating the reproductive system, metabolism, immune responses, and the body's adaptive mechanisms.

This adipokine and inflammatory signaling molecule is linked with adipose tissue, immune cells, insulin resistance, and vascular risk. In ordinary practice it is not a useful home marker for keto control; glucose, insulin, waist size, lipids, blood pressure, and inflammatory markers matter more.

A neurotransmitter involved in regulating mood, sleep, appetite, pain sensitivity, and gastrointestinal tract function. Despite its common name «the happiness hormone», serotonin is primarily a regulator of adaptation, stability of the psycho-emotional background, and physiological rhythms.

A peptide hormone that acts as a physiological brake for the pituitary gland, pancreas, and digestive tract. It matters in rare neuroendocrine conditions, growth hormone disorders, glucose disturbances, and treatment with somatostatin analogues.

Pituitary growth hormone regulates childhood growth, tissue repair, lipolysis, bone and muscle maintenance, but it also affects insulin sensitivity. It is interpreted through symptoms, IGF-1, and formal stimulation or suppression tests, not through a random blood draw alone.

A steroid androgen important for libido, muscle, bone, blood formation, mood, and metabolism in both men and women. It should not be judged from one random test: morning timing, SHBG, free testosterone, symptoms, sleep, medication, weight, and pituitary signals matter.

The main thyroid hormone T4 acts as a reservoir for active T3 and influences energy metabolism, temperature, heart function, bowel motility, skin, brain, and lipids. It should be interpreted with TSH, free T4, sometimes free T3, antibodies, symptoms, medications, and context.