Supplement Glossary
66 essential terms and definitions for understanding dietary supplements, from adaptogens to withanolides.
A
Adaptogen
A class of herbs and mushrooms that help the body resist and adapt to physical, chemical, and biological stressors by modulating the hypothalamic-pituitary-adrenal (HPA) axis. Examples include ashwagandha, rhodiola, and holy basil.
Amino Acid
Organic compounds that serve as the building blocks of proteins. There are 20 standard amino acids, 9 of which are essential (must be obtained from diet). Supplements like BCAAs, L-theanine, and NAC are amino acid-based.
AMPK
AMP-activated protein kinase — an enzyme often called the 'metabolic master switch.' It regulates cellular energy balance and is activated by exercise, caloric restriction, and certain supplements like berberine and resveratrol.
Antioxidant
A molecule that inhibits the oxidation of other molecules, protecting cells from damage caused by free radicals. Common antioxidant supplements include vitamin C, vitamin E, CoQ10, NAC, and alpha-lipoic acid.
ATP
Adenosine triphosphate — the primary energy currency of cells. Creatine supplementation increases phosphocreatine stores, which are used to rapidly regenerate ATP during high-intensity exercise.
B
BCAA
Branched-Chain Amino Acids — leucine, isoleucine, and valine. These essential amino acids are popular in sports nutrition for muscle protein synthesis, though whole protein sources (like whey) are generally more effective.
Beta-Glucan
A type of soluble fiber found in the cell walls of mushrooms, yeast, and grains. Beta-glucans from medicinal mushrooms (like Lion's Mane and Reishi) have potent immunomodulating properties.
Bioavailability
The proportion of a supplement that enters the circulation and is available for use by the body. Factors affecting bioavailability include the chemical form, delivery method, and whether it's taken with food. For example, curcumin has ~1% bioavailability alone but 2,000% more with piperine.
Biotin
Also known as vitamin B7, biotin is a water-soluble B vitamin essential for metabolism of fats, carbohydrates, and proteins. Commonly supplemented for hair, skin, and nail health, though evidence for benefits in non-deficient individuals is limited.
C
Carnosine
A dipeptide (beta-alanine + histidine) concentrated in skeletal muscle that acts as an intracellular pH buffer during high-intensity exercise. Beta-alanine supplementation increases muscle carnosine levels.
cGMP
Current Good Manufacturing Practices — FDA regulations that ensure dietary supplements are produced consistently and meet quality standards. Covers facility design, equipment maintenance, production processes, and quality control testing.
Chelated Mineral
A mineral that has been bound to an amino acid or organic acid to improve absorption. Examples include magnesium glycinate (bound to glycine) and zinc picolinate (bound to picolinic acid). Chelated forms are generally better absorbed than inorganic forms.
Choline
An essential nutrient required for cell membrane structure, neurotransmitter synthesis (acetylcholine), and methylation. Most Americans don't get enough from diet alone. Alpha-GPC and CDP-Choline are the most bioavailable supplemental forms.
COA (Certificate of Analysis)
A document from a third-party laboratory that verifies the identity, purity, potency, and contaminant levels of a supplement. Reputable brands make COAs available to consumers upon request or on their website.
Cofactor
A non-protein chemical compound that is required for an enzyme to function. Many vitamins and minerals serve as cofactors — for example, magnesium is a cofactor for over 600 enzymatic reactions in the body.
Collagen
The most abundant protein in the human body, providing structural support to skin, bones, tendons, and cartilage. Hydrolyzed collagen peptides are the most common supplemental form, broken down into smaller, absorbable peptides.
Cortisol
The body's primary stress hormone, produced by the adrenal glands. Chronically elevated cortisol can lead to weight gain, immune suppression, and muscle breakdown. Adaptogens like ashwagandha help modulate cortisol levels.
Curcuminoid
The active compounds in turmeric, with curcumin being the most studied. Curcuminoids have potent anti-inflammatory and antioxidant properties but very poor bioavailability without enhancement technologies like piperine or phytosome formulations.
D
DHA
Docosahexaenoic acid — an omega-3 fatty acid that is a major structural component of the brain (making up ~25% of brain fat) and retina. Critical for brain development and cognitive function throughout life.
DSHEA
Dietary Supplement Health and Education Act of 1994 — the federal law that defines dietary supplements and establishes the regulatory framework. Under DSHEA, supplements do not require FDA approval before marketing, but manufacturers are responsible for safety.
Dual Extraction
A processing method for medicinal mushrooms that uses both hot water extraction (to pull out beta-glucans) and alcohol extraction (to pull out triterpenes and other alcohol-soluble compounds). Considered the gold standard for mushroom supplements.
E
Elemental Amount
The actual amount of a mineral available for absorption, as opposed to the total weight of the mineral compound. For example, magnesium glycinate 500mg may contain only 70mg of elemental magnesium.
Enteric Coating
A polymer coating on tablets or capsules that prevents dissolution in the stomach, allowing the supplement to pass to the small intestine before releasing. Used for ingredients that are degraded by stomach acid or cause GI irritation.
EPA
Eicosapentaenoic acid — an omega-3 fatty acid with potent anti-inflammatory properties. EPA is particularly important for cardiovascular health, mood regulation, and reducing inflammatory markers.
Ergogenic Aid
Any substance or technique that enhances physical performance, endurance, or recovery. Evidence-based ergogenic supplements include creatine, caffeine, beta-alanine, and citrulline.
Essential Nutrient
A nutrient that the body cannot synthesize in sufficient quantities and must be obtained from diet or supplementation. Includes essential amino acids, essential fatty acids, vitamins, and minerals.
F
Fat-Soluble Vitamin
Vitamins that dissolve in fat and can be stored in the body's fatty tissue and liver. Includes vitamins A, D, E, and K. These should be taken with a fat-containing meal for optimal absorption and can accumulate to toxic levels at very high doses.
Free Radical
An unstable molecule with an unpaired electron that can damage cells, proteins, and DNA through oxidation. Free radical damage (oxidative stress) is implicated in aging, cancer, and cardiovascular disease. Antioxidants neutralize free radicals.
Fruiting Body
The above-ground, visible part of a mushroom — the cap and stem. For medicinal mushrooms, fruiting body extracts are generally preferred over mycelium-on-grain products because they contain higher concentrations of active compounds.
G
Glutathione
The body's most important endogenous antioxidant, present in every cell. Essential for detoxification, immune function, and protection against oxidative stress. NAC (N-Acetyl Cysteine) is the most effective oral supplement for raising glutathione levels.
Glycinate
A chelated form of a mineral bound to the amino acid glycine. Magnesium glycinate is one of the most popular and well-absorbed forms of magnesium, prized for its calming effects and minimal GI side effects.
GMP
Good Manufacturing Practices — quality assurance standards for the production of supplements and pharmaceuticals. See cGMP (Current Good Manufacturing Practices) for the FDA's updated requirements.
H
Half-Life
The time it takes for the concentration of a substance in the blood to decrease by half. Important for determining dosing frequency — supplements with short half-lives (like berberine, ~4 hours) need to be taken multiple times daily.
Hericenone
A class of compounds found in the fruiting body of Lion's Mane mushroom that can cross the blood-brain barrier and stimulate Nerve Growth Factor (NGF) synthesis. One of the key reasons Lion's Mane is valued for cognitive health.
HPA Axis
Hypothalamic-Pituitary-Adrenal axis — the body's central stress response system. Adaptogens work primarily by modulating the HPA axis, helping the body maintain homeostasis under stress.
Hydrolyzed
A process where proteins are broken down into smaller peptides using water and enzymes. Hydrolyzed collagen (collagen peptides) and hydrolyzed whey protein are more easily absorbed than their intact forms.
I
Immunomodulator
A substance that modifies the immune response, either by stimulating or suppressing it. Many medicinal mushrooms (reishi, turkey tail) and supplements (vitamin D, zinc) have immunomodulating properties.
L
Liposomal
A delivery technology where the active ingredient is encapsulated in tiny fat-based vesicles (liposomes) that improve absorption. Liposomal vitamin C and liposomal glutathione are common examples of this technology.
Loading Phase
A period of higher-dose supplementation to rapidly saturate tissue stores, followed by a lower maintenance dose. Most commonly associated with creatine (20g/day for 5-7 days, then 5g/day maintenance), though loading is optional.
M
Methylation
A biochemical process where a methyl group (CH3) is added to a molecule. Critical for DNA repair, detoxification, neurotransmitter production, and energy metabolism. Key nutrients for methylation include folate (as methylfolate), B12, and choline.
Microbiome
The community of trillions of microorganisms (bacteria, fungi, viruses) living in and on the human body, primarily in the gut. The gut microbiome influences digestion, immunity, mood, and metabolism. Probiotics and prebiotics support microbiome health.
Mitochondria
The 'powerhouses' of cells — organelles responsible for producing 95% of the body's energy (ATP) through oxidative phosphorylation. CoQ10, PQQ, and L-carnitine are supplements that support mitochondrial function.
Mycelium
The underground root-like network of a fungus. Some mushroom supplements use mycelium grown on grain, which is controversial because these products often contain significant amounts of starch filler from the grain substrate.
N
NGF
Nerve Growth Factor — a protein essential for the growth, maintenance, and survival of neurons. Lion's Mane mushroom is the only known natural compound that stimulates NGF synthesis through its hericenone and erinacine compounds.
Nootropic
A substance that enhances cognitive function, including memory, focus, creativity, and motivation. Can be natural (Lion's Mane, Bacopa, Alpha-GPC) or synthetic (racetams, modafinil). The term was coined by Romanian psychologist Corneliu Giurgea in 1972.
NSF International
An independent organization that tests and certifies supplements for quality, purity, and label accuracy. NSF Certified for Sport is the gold standard for athletes, testing for over 270 banned substances.
O
Oxidative Stress
An imbalance between free radical production and the body's antioxidant defenses, leading to cellular damage. Chronic oxidative stress contributes to aging, cardiovascular disease, neurodegeneration, and cancer.
P
Paresthesia
A tingling or prickling sensation, commonly experienced with beta-alanine supplementation. The tingling is harmless and temporary (15-30 minutes), caused by beta-alanine activating sensory neurons in the skin.
Peptide
A short chain of amino acids (typically 2-50). Collagen peptides, BPC-157, and glutathione are examples of peptide-based supplements. Peptides are smaller than proteins and often better absorbed.
Phytosome
A delivery technology where a plant extract is complexed with phospholipids to improve absorption. Curcumin phytosome (Meriva) has 29x better absorption than standard curcumin.
Piperine
The active compound in black pepper that enhances the bioavailability of many supplements by inhibiting drug-metabolizing enzymes in the gut and liver. Most notably, piperine increases curcumin absorption by 2,000%. BioPerine is the patented form.
Prebiotic
Non-digestible fibers that feed beneficial gut bacteria. Common prebiotics include inulin, FOS (fructooligosaccharides), and GOS (galactooligosaccharides). Prebiotics and probiotics work synergistically for gut health.
Probiotic
Live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Common probiotic strains include Lactobacillus and Bifidobacterium species. CFU (Colony Forming Units) indicates the number of viable organisms.
Proprietary Blend
A supplement label practice where multiple ingredients are listed under a single 'blend' with only the total weight disclosed, not individual amounts. Generally considered a red flag because it hides ingredient dosages from consumers.
R
RDA
Recommended Dietary Allowance — the average daily intake level sufficient to meet the nutrient requirements of 97-98% of healthy individuals. Note that RDAs represent minimum amounts to prevent deficiency, not necessarily optimal amounts for health.
S
Salidroside
One of the primary active compounds in Rhodiola Rosea, responsible for many of its adaptogenic and neuroprotective effects. Quality Rhodiola extracts are standardized to contain at least 1% salidroside.
Standardized Extract
An extract that has been processed to contain a guaranteed minimum percentage of specific active compounds. This ensures consistency between batches and allows meaningful comparison between products.
Sublingual
A method of administration where the supplement is placed under the tongue and absorbed directly into the bloodstream through the mucous membranes. Bypasses the digestive system, providing faster absorption. Common for B12 and some hormones.
Synergy
When two or more supplements work together to produce an effect greater than the sum of their individual effects. Examples: Vitamin D + K2, Curcumin + Piperine, Vitamin C + Iron, Creatine + Beta-Alanine.
T
Terpene
A large class of organic compounds produced by plants and some insects. In supplement context, triterpenes from medicinal mushrooms (like ganoderic acids from Reishi) have anti-inflammatory and immune-modulating properties.
Third-Party Testing
Independent laboratory testing of supplements by organizations not affiliated with the manufacturer. Verifies that products contain what the label claims and are free from contaminants like heavy metals, pesticides, and microbes.
Tolerable Upper Intake Level (UL)
The maximum daily intake of a nutrient that is unlikely to cause adverse health effects. Exceeding the UL increases the risk of toxicity. For example, the UL for vitamin D is 4,000 IU/day (though many experts consider higher doses safe with monitoring).
U
Ubiquinol
The reduced (active) form of Coenzyme Q10 (CoQ10). Better absorbed than ubiquinone (the oxidized form), especially in older adults. Recommended for those over 40 and statin users.
USP
United States Pharmacopeia — a nonprofit organization that sets quality standards for medicines and supplements. USP Verified supplements have been tested for identity, strength, purity, and manufacturing quality.
W
Water-Soluble Vitamin
Vitamins that dissolve in water and are not stored in the body in significant amounts. Includes B vitamins and vitamin C. Excess amounts are excreted in urine, making toxicity rare (with some exceptions like B6).
Withanolide
The primary active compounds in ashwagandha (Withania somnifera). Withanolides are responsible for ashwagandha's adaptogenic, anti-inflammatory, and neuroprotective effects. KSM-66 is standardized to 5% withanolides.