Supplement Glossary A-Z

Over 50 supplement and nutrition terms explained in plain English. Tap a letter to jump.

A

Adaptogen: A natural substance (like ashwagandha or rhodiola) that helps the body adapt to stress and promotes balance in physiological processes.
Amino Acid: The building blocks of protein. There are 20 amino acids, 9 of which are essential and must come from your diet.
Anabolic: Refers to metabolic processes that build complex molecules from simpler ones, such as muscle protein synthesis.
Antioxidant: A compound that neutralises free radicals and protects cells from oxidative damage. Examples include vitamin C, vitamin E, and selenium.

BCAAs: Branched-Chain Amino Acids: leucine, isoleucine, and valine. Often supplemented to support muscle recovery and reduce soreness.
Beta-Alanine: A non-essential amino acid that increases carnosine levels in muscle, helping buffer acid build-up during high-intensity exercise.
Bioavailability: The proportion of a nutrient or supplement that is absorbed and available for use by the body after ingestion.

Caffeine: A natural stimulant found in coffee, tea, and many pre-workout supplements. Improves alertness, focus, and exercise performance.
Casein: A slow-digesting milk protein often taken before bed to provide a sustained release of amino acids during sleep.
Citrulline: An amino acid that boosts nitric oxide production, improving blood flow and exercise performance. Often found in pre-workouts as L-citrulline or citrulline malate.
Collagen: The most abundant protein in the body, supporting skin, joints, bones, and connective tissue. Supplemented as hydrolysed collagen peptides.
Creatine: One of the most researched supplements. Stored in muscle as phosphocreatine, it regenerates ATP for short bursts of high-intensity effort. Creatine monohydrate is the gold standard.

DHA: Docosahexaenoic acid, an omega-3 fatty acid critical for brain health, vision, and reducing inflammation. Found in oily fish and algae.
Digestive Enzymes: Proteins that break down food into absorbable nutrients. Supplemental forms include protease, lipase, and amylase.
DMAE: Dimethylaminoethanol, a compound sometimes used in nootropic supplements for focus and cognitive function.

EAAs: Essential Amino Acids: the 9 amino acids your body cannot produce and must obtain from food or supplements.
Electrolytes: Minerals like sodium, potassium, magnesium, and calcium that conduct electrical signals in the body and regulate hydration.
EPA: Eicosapentaenoic acid, an omega-3 fatty acid with strong anti-inflammatory properties. Found in fish oil alongside DHA.

Fat-Soluble: Vitamins (A, D, E, K) that dissolve in fat and are stored in the body. Best absorbed when taken with a meal containing fat.
Flavonoid: A group of plant compounds with antioxidant properties found in fruits, vegetables, tea, and dark chocolate.

GABA: Gamma-Aminobutyric Acid, a neurotransmitter that promotes relaxation and calm. Supplemented for sleep and stress support.
Glucosamine: A natural compound in cartilage, often supplemented (with chondroitin) to support joint health and reduce stiffness.
Glycaemic Index: A scale ranking carbohydrates by how quickly they raise blood sugar levels. Low GI foods provide slower, steadier energy.

HMB: Beta-Hydroxy Beta-Methylbutyrate, a metabolite of leucine that may help reduce muscle breakdown during intense training or calorie restriction.

Isolate: A highly refined form of protein powder (typically whey) with most fat and lactose removed, yielding 90%+ protein by weight.

L-Carnitine: An amino acid derivative that transports fatty acids into mitochondria for energy production. Supplemented for fat metabolism and recovery.
L-Glutamine: The most abundant amino acid in the body. Supports gut health, immune function, and muscle recovery, especially during intense training.
L-Theanine: An amino acid found in tea that promotes calm focus without drowsiness. Often paired with caffeine for smooth energy.

Macronutrient: The three major nutrients the body needs in large amounts: protein (4 kcal/g), carbohydrates (4 kcal/g), and fat (9 kcal/g).
Micronutrient: Vitamins and minerals needed in smaller amounts but essential for health, immunity, energy production, and hundreds of bodily functions.

Nitric Oxide: A molecule that relaxes blood vessels and improves blood flow. Boosted by ingredients like citrulline, arginine, and beetroot.
Nootropic: A substance that enhances cognitive function, including memory, focus, creativity, or motivation. Examples: caffeine, L-theanine, lion's mane.

Omega-3: A family of essential fatty acids (EPA, DHA, ALA) with anti-inflammatory benefits. Found in oily fish, flaxseed, and walnuts.

Peptide: A short chain of amino acids. Collagen peptides and BPC-157 are examples used in supplementation.
Pre-Workout: A supplement taken before training, typically containing caffeine, citrulline, beta-alanine, and other performance-boosting ingredients.
Probiotic: Live beneficial bacteria that support gut health, digestion, and immune function. Found in yoghurt, kefir, and supplements.
Prebiotic: Non-digestible fibres that feed beneficial gut bacteria. Found in garlic, onions, bananas, and chicory root.
Proprietary Blend: A supplement label listing ingredients without individual doses. Generally considered less transparent than fully disclosed formulas.

RDA: Recommended Dietary Allowance: the daily intake level of a nutrient considered sufficient to meet the requirements of most healthy individuals.

Satiety: The feeling of fullness and satisfaction after eating. High-protein and high-fibre foods tend to promote greater satiety.
Stimulant: A substance that increases alertness, energy, and heart rate. Caffeine is the most common stimulant in supplements.

TDEE: Total Daily Energy Expenditure: the total calories your body burns in a day, combining BMR, activity, digestion, and NEAT.
Thermogenic: A compound that raises body temperature and metabolic rate, potentially increasing calorie burn. Examples: caffeine, green tea extract, capsaicin.
Tincture: A concentrated liquid extract of an herb or supplement, usually made by soaking plant material in alcohol or glycerine.
Turkesterone: An ecdysteroid derived from plants, marketed as a natural anabolic agent. Research in humans is still limited.

Vitamin: An essential organic compound needed in small amounts for normal growth, metabolism, and health. Classified as fat-soluble (A, D, E, K) or water-soluble (B vitamins, C).

Water-Soluble: Vitamins (B-complex, C) that dissolve in water and are not stored long-term. Excess is excreted in urine, so regular intake is important.
Whey: A fast-digesting dairy protein derived from milk during cheese production. The most popular protein supplement, available as concentrate, isolate, or hydrolysate.

ZMA: A supplement combining Zinc, Magnesium Aspartate, and Vitamin B6. Often taken at night to support sleep quality, recovery, and hormone production.