The Most Comprehensive Reference Online

Skincare & Longevity Glossary

Every ingredient, technique, condition and longevity term — fully defined with usage guidance and research links.

125
Terms
15
Categories
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🧬 Peptides💊 Vitamins🧪 Acids✨ Retinoids🌿 Botanicals⚡ Antioxidants🫧 Lipids & Oils💎 Minerals🥗 Oral Supplements🔬 Skin Science🩺 Skin Conditions✋ Techniques🏷 Label Terms⏳ Longevity Science🌱 Health & Wellness
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Peptides

Signalling peptides that stimulate collagen, relax muscles and regenerate skin.

8 terms
Argireline
Acetyl Hexapeptide-3 / Acetyl Hexapeptide-8…
Relaxes facial muscle micro-contractions that cause dynamic wrinkles around the eyes…
Eyeliss
Dipeptide-2 / Hesperidin Methyl Chalcone…
A proprietary peptide complex for the eye area. Dipeptide-2 improves lymphatic drainage…
GHK-Cu
Copper Peptide / Tripeptide-1…
A naturally occurring copper-binding tripeptide that declines with age. Stimulates…
Leuphasyl
Pentapeptide-18…
A neuro-relaxing peptide that inhibits enkephalin degradation, in turn inhibiting…
Matrixyl 3000
Palmitoyl Tripeptide-1 & Palmitoyl Tetrapeptide-7…
One of the most clinically studied peptide complexes. Works via two matrikine peptides:…
Palmitoyl Pentapeptide-4
Original Matrixyl / Pal-KTTKS…
The original Matrixyl peptide — a Pro-Collagen I fragment that directly stimulates…
SNAP-8
Acetyl Octapeptide-3…
An extended version of Argireline with two additional amino acids, designed to interact…
Syn-Ake
Dipeptide Diaminobutyroyl Benzylamide Diacetate…
A synthetic peptide mimicking the mechanism of Waglerin-1 from Temple Viper venom —…
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Vitamins

Topical and oral vitamins with clinically proven skin benefits.

7 terms
High-Dose Niacinamide
Oral Nicotinamide / Skin Cancer Prevention Dose…
At 500mg twice daily orally, niacinamide has a landmark clinical application beyond…
Niacinamide
Vitamin B3 / Nicotinamide…
The most versatile and universally tolerated skincare active. Inhibits melanin transfer…
Panthenol
Vitamin B5 / Pro-Vitamin B5 / D-Panthenol…
Converts to pantothenic acid on absorption. Functions as a powerful humectant,…
Vitamin B12
Cobalamin / Cyanocobalamin…
A water-soluble vitamin with significant topical evidence for inflammatory skin…
Vitamin C
L-Ascorbic Acid / Ascorbyl Glucoside / MAP / THDA…
The gold-standard antioxidant for skin. L-Ascorbic Acid neutralises free radicals,…
Vitamin D
Cholecalciferol / Calcitriol / Sunshine Vitamin…
Synthesised in skin from sunlight, Vitamin D is critical for skin barrier function,…
Vitamin E
Tocopherol / Alpha-Tocopherol…
The primary fat-soluble antioxidant in skin. Protects cell membranes from lipid…
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Acids

AHAs, BHAs, PHAs and other exfoliating and treating acids.

10 terms
Azelaic Acid
Nonanedioic Acid (grain-derived)…
A dicarboxylic acid from grains with a uniquely versatile clinical profile:…
Benzoyl Peroxide
BPO…
One of the most effective OTC acne treatments. An oxidising agent that directly kills…
Glycolic Acid
AHA / Alpha Hydroxy Acid…
The smallest AHA molecule — 76 daltons — allowing the deepest penetration and most…
Hyaluronic Acid
Sodium Hyaluronate / HA / Multi-Weight HA…
A glycosaminoglycan naturally present throughout the body, holding up to 1000x its…
Kojic Acid
Tyrosinase Inhibitor / Fermentation-Derived Brightener…
A chelating agent derived from fungal fermentation (sake, soy sauce). Competitively…
Lactic Acid
AHA / Alpha Hydroxy Acid (milk-derived)…
The gentlest commonly used AHA — larger molecular weight than glycolic means shallower…
Mandelic Acid
AHA (almond-derived) / 152 Dalton AHA…
The largest commonly used AHA — 152 daltons — giving the slowest and most superficial…
PHAs
Polyhydroxy Acids / Gluconolactone / Lactobionic Acid…
Next-generation exfoliants larger than AHAs — the gentlest chemical exfoliants…
Salicylic Acid
BHA / Beta Hydroxy Acid…
The only BHA widely used in skincare and the gold standard for acne and congested skin.…
Tranexamic Acid
TXA…
Originally a pharmaceutical antifibrinolytic, TXA is now one of the most effective…
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Retinoids

Vitamin A derivatives — the most evidence-backed anti-aging actives.

7 terms
Adapalene
Differin / Third-Generation Retinoid…
Third-generation synthetic retinoid — selective for RARβ and RARγ subtypes and…
Bakuchiol
Plant Retinol Alternative / Babchi-Derived…
A meroterpene phenol from Psoralea corylifolia seeds. A landmark 2019 BJD double-blind…
Retinaldehyde
Retinal / RAL…
One enzymatic step closer to retinoic acid than retinol — approximately 11x more…
Retinol
Vitamin A (OTC) / All-Trans Retinol…
The most evidence-backed OTC anti-aging ingredient. Converts in skin to retinaldehyde…
Retinyl Palmitate
Vitamin A Ester / Most Gentle Retinoid…
The most stable and least irritating form of topical Vitamin A — requires two…
Retinyl Retinoate
HP-Retinol / Hybrid Retinoid…
A next-generation retinoid ester combining retinol and retinoic acid in one molecule.…
Tretinoin
Retinoic Acid / Prescription Vitamin A / Retin-A…
The active form of Vitamin A — the most potent and clinically studied retinoid. Binds…
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Botanicals

Plant-derived actives with clinical evidence for skin benefits.

11 terms
Aloe Vera
Aloe Barbadensis / Acemannan / Aloesin…
Contains polysaccharides, glycoproteins, aloesin, anthraquinones and minerals with…
Centella Asiatica
Cica / Gotu Kola / Tiger Grass…
One of the most clinically validated plant-based actives. Rich in triterpenoid saponins…
Colloidal Oatmeal
Avena Sativa / Avenanthramides / FDA Skin Protectant…
FDA-approved as an OTC skin protectant. Contains beta-glucan (barrier-forming…
Ectoin
Ectoine / Extremolyte / Stress Protector…
A natural extremolyte produced by extremophilic bacteria to protect cellular structures…
Green Tea Extract
EGCG / Epigallocatechin Gallate / Camellia Sinensis…
Rich in catechins, primarily EGCG — a potent free-radical scavenger, anti-inflammatory,…
Licorice Root Extract
Glycyrrhiza Glabra / Glabridin / Licochalcone A…
A well-studied plant-derived brightener. Glabridin inhibits tyrosinase and has…
Neem Extract
Azadirachta Indica / Nimbidin…
Ayurvedic botanical with potent antibacterial, antifungal and anti-inflammatory…
Resveratrol
Trans-Resveratrol / Stilbenoid / Grape Skin Extract…
A polyphenol from grape skin, red wine and blueberries. Activates sirtuin enzymes…
Rosehip Seed Oil
Rosa Canina / Rosa Rubiginosa Seed Oil…
Cold-pressed oil rich in linoleic acid (36–45%), alpha-linolenic acid (19–30%) and…
Sulforaphane
Broccoli Sprout Extract / NRF2 Activator / Glucoraphani…
An isothiocyanate from cruciferous vegetables — one of the most potent activators of…
Turmeric Extract
Curcumin / Curcuma Longa…
Curcumin is a potent anti-inflammatory, antioxidant and tyrosinase-inhibiting…
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Antioxidants

Free-radical neutralisers that protect against UV, pollution and aging.

8 terms
Adenosine
Purine Nucleoside / FDA Anti-Wrinkle Ingredient…
A naturally occurring purine nucleoside with FDA-approval as an anti-wrinkle ingredient…
Alpha Lipoic Acid
ALA / Thioctic Acid / Universal Antioxidant…
The "universal antioxidant" — unique in being both water- and fat-soluble, allowing it…
Astaxanthin
Keto-Carotenoid / Marine Carotenoid / HPA…
A xanthophyll carotenoid from microalgae — considered one of the most potent natural…
Caffeine
1,3,7-Trimethylxanthine / Eye Area Vasoconstrictor…
Topical caffeine works as a potent vasoconstrictor (reducing undereye puffiness and…
Coenzyme Q10
CoQ10 / Ubiquinol / Mitochondrial Antioxidant…
A fat-soluble quinone essential for mitochondrial ATP production. Levels in skin…
Ferulic Acid
Hydroxycinnamic Acid / Antioxidant Booster…
A plant-derived antioxidant found in cell walls of grains and seeds. Most important…
Glutathione
GSH / Reduced Glutathione / Master Antioxidant…
The body's most abundant endogenous antioxidant, produced in every cell. In skin,…
N-Acetyl Cysteine
NAC / Glutathione Precursor…
A precursor to glutathione — the body's primary endogenous antioxidant. Replenishes…
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Lipids & Oils

Skin-identical lipids, occlusives and emollients that repair the barrier.

7 terms
Ceramides
Ceramide NP / AP / EOP / Skin Barrier Lipids…
Lipids constituting ~50% of the stratum corneum intercellular matrix. Together with…
Dimethicone
Silicone / Polydimethylsiloxane / Breathable Barrier…
A synthetic silicone polymer used as a skin protectant, occlusive and texture enhancer.…
Jojoba Oil
Simmondsia Chinensis Seed Oil / Liquid Wax…
Technically a liquid wax rather than a triglyceride oil — composed primarily of…
Linoleic Acid
Omega-6 Fatty Acid / LA / Barrier Essential…
An essential omega-6 fatty acid critical for ceramide production. Without adequate…
Petrolatum
Petroleum Jelly / Vaseline / White Petrolatum…
One of the most effective occlusives in existence — reduces TEWL by up to 98%, more…
Shea Butter
Butyrospermum Parkii / Karite Butter…
Extracted from the African shea tree nut. Rich in oleic and stearic acid, with…
Squalane
Hydrogenated Squalene / Plant-Derived Squalane…
A saturated, stable form of squalene — a skin lipid that declines dramatically after…
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Minerals

Topical and oral minerals essential for skin health and UV protection.

3 terms
Magnesium
Magnesium Glycinate / Magnesium L-Threonate…
Involved in 600+ enzymatic reactions including DNA repair, inflammation control, stress…
SPF / Sunscreen
Zinc Oxide / Titanium Dioxide / Broad-Spectrum UV Filte…
The single most evidence-backed anti-aging intervention. UV drives 80–90% of visible…
Zinc
Zinc PCA / Zinc Oxide / Sebum Regulator…
Topical zinc PCA regulates sebum via 5-alpha reductase inhibition, kills C. acnes,…
🥗

Oral Supplements

Supplements with clinical evidence for skin, hair, nails and longevity.

10 terms
Berberine
BBR / AMPK Activator / Nature's Metformin…
An isoquinoline alkaloid from plants that activates AMPK — the master metabolic…
Biotin
Vitamin B7 / Vitamin H / Keratin Synthesis Vitamin…
A water-soluble B-vitamin essential for keratin synthesis — the structural protein of…
Collagen Peptides
Marine / Bovine Hydrolysed Collagen…
Hydrolysed collagen (short-chain peptides) are bioavailable and proven to stimulate…
NMN
Nicotinamide Mononucleotide / Direct NAD+ Precursor…
One step closer to NAD+ in the biosynthesis pathway than NR. Human clinical trials show…
Nicotinamide Riboside
NR / NAD+ Precursor / Tru Niagen…
A form of Vitamin B3 that serves as a highly bioavailable NAD+ precursor. NAD+ levels…
Omega-3 Fatty Acids
EPA / DHA / Fish Oil / ALA…
Essential fatty acids reducing production of inflammatory cytokines (IL-6, TNF-α),…
Oral Hyaluronic Acid
Hyaluron Supplement / HA Oral…
Low-molecular-weight oral HA (<10kDa) from fermented bacterial sources shows superior…
Orthosilicic Acid
Colloidal Silica / Biosil / ch-OSA…
The bioavailable form of dietary silicon, involved in collagen hydroxylation,…
Probiotics
Lactobacillus / Bifidobacterium / Gut-Skin Axis…
The gut-skin axis is a well-established relationship: gut dysbiosis is associated with…
Spermidine
Polyamine / Autophagy Activator…
A naturally occurring polyamine and one of the most potent known inducers of autophagy…
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Skin Science

Core concepts in skin biology, barrier function and dermatology.

14 terms
Acid Mantle
Skin pH / Surface Acid Film…
A thin, slightly acidic film on the surface of the skin with a natural pH of…
Collagen (Protein)
Type I / III / IV Collagen / Extracellular Matrix…
The most abundant protein in the human body — accounting for approximately 80% of the…
Comedogenicity
Comedogenic Rating / Pore-Clogging Scale…
The tendency of a topical ingredient or product to cause or worsen comedones (clogged…
Desquamation
Cell Turnover / Skin Shedding…
The natural process by which the outermost dead skin cells (corneocytes) are…
Elastin
Elastic Fibres / Skin Elasticity Protein…
A highly elastic protein in the dermis responsible for skin's ability to snap back…
Fitzpatrick Scale
Fitzpatrick Skin Type / FST I–VI…
A numerical classification system developed by Harvard dermatologist Thomas Fitzpatrick…
Free Radicals
ROS / Reactive Oxygen Species / Oxidative Stress…
Unstable molecules with unpaired electrons that cause oxidative damage to cellular…
Glycation
Advanced Glycation End Products / AGEs / Sugar-Skin Dam…
A non-enzymatic chemical reaction in which sugar molecules (glucose, fructose) attach…
Melanin
Eumelanin / Phaeomelanin / Pigment…
The pigment produced by melanocytes in the basal layer of the epidermis that determines…
Sebum
Skin Oil / Natural Oil / Lipid Film…
An oily, waxy substance produced and secreted by sebaceous glands — primarily composed…
Skin Barrier
Moisture Barrier / Lipid Barrier / Barrier Function…
A broad term encompassing the multiple defence mechanisms of the skin — primarily the…
Skin Microbiome
Cutaneous Microbiome / Skin Flora / Commensal Bacteria…
The community of microorganisms — bacteria, fungi, viruses and mites — that live on and…
Stratum Corneum
SC / Horny Layer / Outermost Skin Layer…
The outermost layer of the epidermis — approximately 10–20 cells thick, composed of…
Transepidermal Water Loss
TEWL…
The passive diffusion of water vapour from inside the body through the epidermis to the…
🩺

Skin Conditions

Common skin conditions — causes, mechanisms and treatment approaches.

6 terms
Acne Vulgaris
Acne / Pimples / Spots / Breakouts…
A chronic inflammatory skin condition involving the hair follicle and sebaceous gland…
Eczema
Atopic Dermatitis / AD / Atopic Eczema…
A chronic inflammatory skin condition characterised by intensely itchy, dry, inflamed…
Hyperpigmentation
Dark Spots / Uneven Skin Tone / PIH / Melasma…
An umbrella term for patches of skin that are darker than the surrounding area, caused…
Photoaging
Extrinsic Aging / UV-Induced Aging / Solar Aging…
Premature skin aging caused by cumulative ultraviolet radiation exposure — distinct…
Rosacea
Rosacea Subtypes / Facial Redness / Couperose…
A chronic inflammatory skin condition characterised by facial redness, flushing,…
Skin Dehydration
Dehydrated Skin / Dehydrated vs Dry Skin…
A temporary skin condition (not a skin type) characterised by a lack of water in the…
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Techniques

Application methods and skincare protocols for better results.

7 terms
Double Cleansing
Oil Cleanse + Water Cleanse / K-Beauty Cleansing…
A two-step cleansing method originating in Korean beauty: a first cleanse with an…
Gua Sha
Facial Gua Sha / Jade/Rose Quartz Tool…
A traditional Chinese medicine technique adapted for facial use, involving gentle…
Patch Testing
Skin Patch Test / Allergy Test…
The practice of applying a new skincare product to a small, discreet area of skin…
Product Layering Order
Skincare Application Order / Routine Order / Thin to Th…
The principle that skincare products should be applied in order of ascending molecular…
Sandwich Technique
Buffering Retinol / Retinol Sandwich / Moisturiser Buff…
A method for reducing the irritation associated with retinoids by "sandwiching" the…
Skin Cycling
4-Night Skin Cycle / Exfoliate-Retinol-Recover Protocol…
A structured skincare rotation protocol popularised by dermatologist Dr. Whitney Bowe…
Slugging
Petrolatum Occlusion / Overnight Moisturising Technique…
A skincare technique involving the application of a thin layer of an occlusive agent —…
🏷

Label Terms

Ingredient label terminology, formulation terms and regulatory labels.

10 terms
Emollient
Smoothing Agent / Softening Ingredient…
An ingredient that softens and smooths the skin by filling in the gaps between skin…
Fragrance / Parfum
Fragrance Complex / Perfume / Allergen…
Fragrance in skincare is listed as "fragrance" or "parfum" on ingredient labels, often…
Humectant
Water-Binding Agent / Moisture Magnet…
An ingredient that attracts and binds water molecules to itself — pulling moisture from…
INCI
International Nomenclature of Cosmetic Ingredients / In…
The standardised international naming system for cosmetic and personal care…
Non-Comedogenic
Non-Pore-Clogging / Non-Acnegenic…
A claim that a product or ingredient has been tested or formulated to not clog pores or…
Occlusive
Sealant / TEWL Reducer / Barrier Sealant…
An ingredient that forms a physical film on the skin surface to slow transepidermal…
Parabens
Methylparaben / Propylparaben / Preservative Class…
A class of widely used synthetic preservatives (methylparaben, ethylparaben,…
SPF Rating
Sun Protection Factor / SPF Number / PA Rating…
SPF (Sun Protection Factor) is a measure of a sunscreen's ability to protect against…
Surfactant
Surface Active Agent / Cleansing Agent / Detergent…
Molecules with a hydrophilic (water-loving) head and a hydrophobic (oil-loving) tail…
pH
Potential of Hydrogen / Skin pH / Product pH…
A logarithmic scale from 0–14 measuring the acidity or alkalinity of a substance.…
⏳

Longevity Science

Cellular aging mechanisms and evidence-based longevity interventions.

9 terms
Autophagy
Cellular Self-Cleaning / Lysosomal Degradation…
A fundamental cellular recycling process — from Greek "self-eating" — by which cells…
Cellular Senescence
Senescent Cells / Zombie Cells / SASP…
A state of stable, permanent cell cycle arrest that cells enter in response to various…
Epigenetic Clock
Biological Age / DNA Methylation Clock / Horvath Clock…
A computational tool developed by biostatistician Steve Horvath in 2013 that estimates…
Hormesis
Adaptive Stress Response / What Doesn't Kill You / Xeno…
A biological principle describing a beneficial adaptive response to low doses of a…
Inflammaging
Chronic Sterile Inflammation / Low-Grade Inflammation o…
A portmanteau coined by immunologist Claudio Franceschi describing the chronic,…
NAD+
Nicotinamide Adenine Dinucleotide / Cellular Energy Cur…
A coenzyme found in every living cell, essential for mitochondrial energy production…
Sirtuins
SIRT1–7 / Longevity Genes / NAD-Dependent Deacetylases…
A family of seven NAD+-dependent protein deacylases (SIRT1–7) that regulate a wide…
Telomeres
Chromosomal End Caps / Telomere Length / Hayflick Limit…
Repetitive DNA sequences (TTAGGG repeats in humans) that cap the ends of chromosomes,…
mTOR
Mechanistic Target of Rapamycin / Nutrient Sensor…
A central nutrient-sensing kinase that integrates signals from amino acids, growth…
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Health & Wellness

Lifestyle, nutrition and wellness factors that directly affect skin health.

8 terms
Blue Light
HEV Light / High-Energy Visible Light / Digital Aging…
High-energy visible (HEV) light in the 380–450nm wavelength range, emitted by the sun…
Circadian Rhythm
Circadian Biology / Body Clock / Chrono-Skincare…
The approximately 24-hour internal biological clock that regulates physiological…
Cortisol
Stress Hormone / HPA Axis / Glucocorticoid…
The primary glucocorticoid stress hormone produced by the adrenal cortex, essential for…
Gut-Skin Axis
Gut Microbiome Skin Connection / Enteric-Cutaneous Axis…
The bidirectional communication network between the gut microbiome and the skin,…
Inflammation
Acute vs Chronic Inflammation / Inflammatory Response…
A fundamental biological response to harmful stimuli — infection, injury, or irritation…
Nutrition & Skin
Diet and Skin / Food and Acne / Skin Nutrition…
The relationship between dietary patterns and skin health is robustly supported by…
Sleep & Skin Health
Beauty Sleep / Overnight Skin Repair / Sleep and Aging…
Sleep is arguably the most powerful non-topical intervention for skin health and…
Sun Protection Behaviour
UV Avoidance / Sun Safety / Photoprotection…
The lifestyle habits and practices that reduce cumulative UV exposure beyond just…