Glossary
132 terms used in supplement research and evidence evaluation.
Study Types
A detailed description of a single patient's experience with a supplement.
A research study that tests a supplement or intervention in human participants.
An observational study tracking a group of people over time to assess outcomes.
A study where participants receive both the treatment and placebo in sequence.
A study examining how different supplement doses affect outcomes.
A trial where neither participants nor researchers know who receives the treatment.
An analysis including all participants as originally assigned, regardless of compliance.
A laboratory study conducted on cells or tissues outside a living organism.
A study conducted in a living organism, typically animal models.
A statistical method combining results from multiple studies for stronger conclusions.
A study that observes outcomes without intervening or assigning treatments.
A trial where both participants and researchers know who receives the treatment.
Evaluation of research by independent experts before publication.
A small preliminary study to test feasibility before a full-scale trial.
A study comparing the supplement against an inert substance to isolate true effects.
A study where participants are randomly assigned to treatment or control groups.
A comprehensive review that identifies and critically evaluates all relevant studies on a topic.
A break between treatment periods to eliminate residual effects of the previous intervention.
Nutrients & Supplements
An adaptogenic herb used to reduce stress and cortisol levels.
A carotenoid antioxidant from microalgae with potent free-radical scavenging activity.
A B-vitamin essential for keratin production and hair, skin, and nail health.
The most abundant mineral in the body, essential for bones, muscles, and nerve function.
An antioxidant compound essential for cellular energy production.
The most abundant protein in the body, supporting skin, hair, joints, and connective tissue.
Small protein fragments bound to copper ions, studied for wound healing and tissue remodeling.
The active compound in turmeric with potent anti-inflammatory and antioxidant properties.
Indigestible plant material that supports digestive health and gut microbiome diversity.
A B-vitamin essential for DNA synthesis, cell division, and tissue growth.
A trace mineral essential for thyroid hormone production.
A mineral essential for oxygen transport and red blood cell production.
A Pacific Island plant (Piper methysticum) containing kavalactones with anxiolytic properties.
An essential amino acid involved in collagen formation, iron absorption, and immune function.
An amino acid from tea leaves that promotes relaxation without sedation.
A mineral involved in 600+ enzymatic reactions, including sleep and stress regulation.
A hormone regulating the sleep-wake cycle, produced by the pineal gland.
A precursor to glutathione, the body's master antioxidant.
Essential fats (EPA/DHA) with anti-inflammatory properties supporting cardiovascular and brain health.
Live microorganisms that confer health benefits when consumed in adequate amounts.
A spice (Crocus sativus) containing crocin and safranal with antidepressant and sleep-support properties.
A botanical extract that may inhibit 5-alpha-reductase, studied for hair loss.
A trace mineral essential for thyroid function and antioxidant defense.
A trace mineral involved in collagen cross-linking and connective tissue integrity.
An amino sulfonic acid with inhibitory neurotransmitter properties, modulating GABA and glycine receptors.
A fat-soluble vitamin essential for vision, immunity, and cell differentiation.
A B-vitamin essential for nerve function, DNA synthesis, and red blood cell formation.
A water-soluble antioxidant essential for collagen synthesis and immune function.
A fat-soluble vitamin crucial for calcium absorption, immunity, and overall health.
A fat-soluble antioxidant protecting cell membranes from oxidative damage.
An essential mineral supporting immunity, wound healing, and protein synthesis.
Mechanisms of Action
An enzyme that converts testosterone to DHT, the hormone linked to pattern hair loss.
The process by which nutrients pass from the digestive tract into the bloodstream.
A class of herbs and compounds that may help the body resist and adapt to physical and mental stress.
A property or substance that reduces inflammation in the body.
A substance that neutralizes free radicals, protecting cells from oxidative damage.
Programmed cell death — a controlled process essential for tissue homeostasis.
The proportion of a supplement that is absorbed and available for use by the body.
A selective barrier of endothelial cells that controls which substances enter the brain from blood.
The body's internal 24-hour clock regulating sleep-wake cycles and physiological processes.
The biological process of producing collagen protein in the body.
The body's primary stress hormone, produced by the adrenal glands.
Small signaling proteins released by immune cells to regulate inflammation and immunity.
A potent androgen hormone that drives pattern hair loss by miniaturizing hair follicles.
An unstable molecule that damages cells by stealing electrons from other molecules.
The brain's primary inhibitory neurotransmitter, promoting calm and sleep.
The body's master antioxidant, a tripeptide produced in every cell.
The three-phase cycle (anagen, catagen, telogen) of human hair follicle growth.
The time required for the body to eliminate half of a substance's active amount.
The class of psychoactive compounds in kava responsible for anxiolytic and sedative effects.
The chemical processes by which the body converts nutrients into energy and building blocks.
The community of trillions of microorganisms living in and on the human body.
A chemical messenger transmitting signals between nerve cells in the brain and body.
A glutamate receptor involved in synaptic plasticity, memory, and neural excitability.
An imbalance between free radical production and the body's antioxidant defenses.
Plant-derived compounds that can bind estrogen receptors and modulate hormonal activity.
A neurotransmitter regulating mood, sleep, appetite, and the precursor to melatonin.
Temporary hair shedding caused by stress, illness, or nutritional deficiency.
A metabolic pathway that converts toxic ammonia into urea for excretion by the kidneys.
Health Conditions
An autoimmune condition causing patchy hair loss when the immune system attacks hair follicles.
Rapid hair loss during the active growth phase, typically caused by chemotherapy or toxins.
The most common form of hair loss, driven by genetics and DHT hormone.
A condition where the blood lacks enough healthy red blood cells or hemoglobin.
Persistent excessive worry or fear that interferes with daily activities.
Misalignment between the body's internal clock and external environment.
Gradual loss of memory, attention, and thinking ability with aging.
Inflammation of the skin causing itching, redness, and irritation.
Persistent tiredness or exhaustion not relieved by rest.
An imbalance in the gut microbial community linked to inflammation and disease.
A state of elevated physiological and cognitive activation that interferes with sleep onset.
Underactive thyroid gland producing insufficient thyroid hormones.
The immune system's response to injury or infection, which can become chronic and harmful.
Persistent difficulty falling asleep, staying asleep, or waking too early.
Discomfort, aching, or soreness in any joint of the body.
A cluster of conditions increasing risk of heart disease, stroke, and diabetes.
An inadequate level of a vitamin or mineral needed for normal body function.
Cellular harm caused by excess free radicals overwhelming antioxidant defenses.
An irresistible urge to move the legs, especially at rest and in the evening.
The condition of the scalp skin and follicular environment affecting hair growth.
A disorder where breathing repeatedly stops and starts during sleep.
The body's physiological and psychological response to perceived threats or demands.
Hot flashes and night sweats caused by hormonal changes, particularly during menopause.
Research Measurements
A measurable indicator of a biological state, used to assess health and treatment response.
A range of values likely to contain the true effect size, typically at 95% confidence.
A measure of the magnitude of a treatment's impact, independent of sample size.
A graphical display showing individual study results and the pooled meta-analysis estimate.
A scatter plot used to detect publication bias in meta-analyses.
A measure comparing the rate of an event occurring between two groups over time.
The degree of variation in study results across a meta-analysis.
A measure of the percentage of variability across studies due to true differences.
How many people need to take a supplement for one additional person to benefit.
The ratio of odds of an event in the treatment group vs. the control group.
Improvement in symptoms due to the belief of receiving treatment, not the treatment itself.
The tendency for studies with positive results to be published more often than negative ones.
The probability of observing results as extreme as the data, assuming no true effect.
The ratio of event probability in the treatment group vs. the control group.
The number of participants enrolled in a study.
A measure of how spread out data values are from the average.
A result unlikely to have occurred by chance, typically at p < 0.05.
A consistent error in study design that skews results in one direction.
Regulatory & Compliance
The system for reporting serious side effects from supplements to the FDA.
A document verifying a supplement batch's tested potency, purity, and contaminant levels.
A claim that a product treats, cures, or prevents a disease — prohibited for supplements.
When a dietary supplement alters the effectiveness or safety of a prescription medication.
The 1994 US law regulating dietary supplements as a special food category.
The US agency responsible for regulating food, drugs, and dietary supplements.
Manufacturing standards ensuring supplement quality, purity, and consistency.
Liver damage caused by drugs, supplements, or other chemicals.
A participant's voluntary agreement to join a study after understanding its risks and procedures.
A certification indicating a supplement has been tested for safety and label accuracy.
A claim describing how a supplement affects the body's structure or function, not disease.
Independent laboratory verification of a supplement's contents, purity, and potency.
The maximum daily nutrient intake unlikely to cause adverse health effects.
A certification indicating a supplement meets rigorous quality standards set by the US Pharmacopeia.