Skincare Ingredient Master Index + Glossary

A practical, pro-level reference for readers.

Each entry includes:

Definition
Benefits
Common Products
Effective Concentration (typical OTC range; formula and pH matter)
Storage & Packaging

Quick notes: Light and air degrade many actives. Opaque, airless pumps beat droppers. Heat speeds oxidation. For exfoliating acids, pH controls strength as much as percentage. For sunscreen, prioritize SPF 30 or higher, broad-spectrum protection from a trusted brand.

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Vitamin A Family — Retinoids and Alternatives

Retinol

Definition: Classic OTC vitamin A that converts to retinal, then retinoic acid in skin.
Benefits: Lines, texture, tone, acne, pores, collagen support.
Common Products: Night serums, creams, eye treatments.
Effective Concentration: 0.1–1%. Start low if sensitive.
Storage & Packaging: Light and air sensitive. Opaque, airless. Night use.

Retinal (Retinaldehyde)

Definition: One step from retinoic acid. Faster-acting than retinol.
Benefits: Similar to retinol, often with quicker results and good tolerability.
Common Products: Night serums, creams.
Effective Concentration: 0.05–0.1%.
Storage & Packaging: Opaque, airless. Night use.

Hydroxypinacolone Retinoate (HPR, “Granactive Retinoid”)

Definition: Retinoic acid ester that can bind to retinoid receptors directly.
Benefits: Anti-aging and anti-acne with often lower irritation.
Common Products: Night serums, creams.
Effective Concentration: 0.2–1% active HPR (labels may show higher blend %).
Storage & Packaging: Light sensitive. Opaque, airless. Night use.

Retinyl Esters (Retinyl Palmitate, Retinyl Propionate)

Definition: Mildest OTC retinoids that must convert through several steps.
Benefits: Gentle maintenance, antioxidant support.
Common Products: Moisturizers, eye creams.
Effective Concentration: Often 0.1–1%+. Efficacy is modest.
Storage & Packaging: Opaque, airless preferred. Night use.

Prescription Retinoids (Tretinoin, Adapalene, Tazarotene)

Definition: Active retinoic acid or synthetic analogs.
Benefits: Gold standard for acne and photoaging.
Common Products: Rx creams and gels.
Effective Concentration: Per Rx. Common: tretinoin 0.025–0.1%, adapalene 0.1–0.3%.
Storage & Packaging: Follow label. Night use, avoid light.

Bakuchiol

Definition: Plant-derived antioxidant sometimes positioned as a retinol alternative.
Benefits: Texture, tone, fine lines, antioxidant support.
Common Products: Serums, oils, creams.
Effective Concentration: 0.5–1%.
Storage & Packaging: Protect from light and heat.

Exfoliating Acids and Enzymes

AHAs (family overview)

Definition: Water-soluble acids that exfoliate surface layers. Key types below.
Benefits: Radiance, smooth texture, fade spots, support collagen.
Common Products: Toners, serums, masks, peels.
Effective Concentration: Daily use 4–10% at pH ~3–4. Masks up to ~30%.
Storage & Packaging: Opaque best. Avoid heat. Use SPF daily.

Glycolic Acid

Benefits: Strongest AHA. Texture, brightness, photoaging.
Effective Concentration: 4–10% daily, 20–30% peels.

Lactic Acid

Benefits: Gentle AHA with hydration. Brightens, smooths.
Effective Concentration: 5–10% daily, 10–15% weekly.

Mandelic Acid

Benefits: Larger molecule, gentler, helpful for acne-prone or sensitive skin.
Effective Concentration: 5–10%.

Citric, Malic, Tartaric Acids

Benefits: Supportive AHAs often used in blends for pH and synergy.
Effective Concentration: Usually part of complexes. Percent varies.

BHA — Salicylic Acid

Definition: Oil-soluble exfoliant that clears inside pores.
Benefits: Blackheads, acne, texture, visible pores.
Common Products: Toners, cleansers, spot treatments.
Effective Concentration: 0.5–2% OTC.
Storage & Packaging: Opaque, airtight preferred. Daily SPF.

LHA — Capryloyl Salicylic Acid

Definition: Lipophilic salicylic derivative with gentle, targeted action.
Benefits: Refines texture and pores with good tolerability.
Common Products: Serums, toners.
Effective Concentration: 0.3–1%.
Storage & Packaging: Protect from light and heat.

PHAs — Gluconolactone, Lactobionic Acid

Definition: Next-gen exfoliants with larger molecules and humectant action.
Benefits: Gentle smoothing, hydration, antioxidant support.
Common Products: Toners, serums, moisturizers.
Effective Concentration: 5–10%.
Storage & Packaging: Generally stable. SPF daily.

Enzyme Exfoliants — Papain, Bromelain, Pumpkin

Definition: Proteolytic enzymes that digest surface dead cells.
Benefits: Instant smoothness with low irritation.
Common Products: Masks, cleansers.
Effective Concentration: Varies by extract potency. Look for reputable brands.
Storage & Packaging: Keep dry and cool. Avoid heat and humidity.

Brighteners and Tone-Evening Agents

Vitamin C — L-Ascorbic Acid (LAA)

Definition: Active water-soluble vitamin C.
Benefits: Brightens, fades dark spots, supports collagen, antioxidant.
Common Products: Serums.
Effective Concentration: 10–20% at pH ~2.5–3.5.
Storage & Packaging: Amber or opaque, airless, cool storage. Use quickly after opening.

Vitamin C Derivatives — 3-O-Ethyl Ascorbic Acid, THD Ascorbate, SAP, MAP, AA-2G

Definition: Stabilized vitamin C forms that convert in skin.
Benefits: Brightening, antioxidant. Often gentler than LAA.
Common Products: Serums, creams, oils (THD is oil-soluble).
Effective Concentration: 5–15% typical. Evidence varies by form.
Storage & Packaging: Opaque, avoid heat. THD stable in oils.

Azelaic Acid

Definition: Dicarboxylic acid with antibacterial and tyrosinase-inhibiting action.
Benefits: Redness-prone skin, acne, post-acne marks, melasma support.
Common Products: Creams, gels, serums.
Effective Concentration: 10% OTC, 15–20% Rx.
Storage & Packaging: Stable. Avoid excess heat.

Tranexamic Acid

Definition: Amino acid derivative that targets pigment pathways.
Benefits: Melasma, PIH, general tone unevenness.
Common Products: Serums, spot correctors.
Effective Concentration: 2–5%.
Storage & Packaging: Opaque preferred.

Alpha-Arbutin and Arbutin

Definition: Hydroquinone glycosides that release HQ slowly in skin.
Benefits: Dark spots, overall brightening with good tolerability.
Common Products: Serums, creams.
Effective Concentration: 1–2% alpha-arbutin. Arbutin similar but less potent.
Storage & Packaging: Protect from heat and light.

Kojic Acid

Definition: Tyrosinase inhibitor produced by fermentation.
Benefits: Dark spots, melasma support.
Common Products: Serums, creams, soaps.
Effective Concentration: 1–2% to balance efficacy and tolerance.
Storage & Packaging: Opaque. Can discolor with air exposure.

Licorice Extract (Glabridin, Licochalcone A)

Definition: Botanical brightener and anti-inflammatory.
Benefits: Redness control, PIH, melasma support.
Common Products: Serums, moisturizers, eye products.
Effective Concentration: Standardized actives often 0.5–1%.
Storage & Packaging: Protect from light.

N-Acetyl Glucosamine (NAG)

Definition: Amino sugar that pairs well with niacinamide for spots.
Benefits: Tone evening, barrier support.
Common Products: Serums, moisturizers.
Effective Concentration: 2–6%.
Storage & Packaging: Stable. Opaque preferred.

Cysteamine

Definition: Potent pigment modulator used as short-contact therapy.
Benefits: Melasma, stubborn hyperpigmentation.
Common Products: Dedicated creams.
Effective Concentration: 5% used in many clinical products.
Storage & Packaging: Follow label. Can have odor. Keep cool.

Thiamidol (Isobutylamido Thiazolyl Resorcinol)

Definition: Targeted tyrosinase inhibitor.
Benefits: Dark spots and melasma support.
Common Products: Serums, spot correctors.
Effective Concentration: ~0.2% in many formulas.
Storage & Packaging: Opaque, avoid heat.

4-Butylresorcinol (Rucinol)

Definition: Resorcinol derivative that reduces excess pigment.
Benefits: Brown spots, tone irregularities.
Common Products: Serums.
Effective Concentration: 0.3–1%.
Storage & Packaging: Opaque, cool storage.

Hydroquinone (Rx in the U.S.)

Definition: Direct tyrosinase inhibitor, dermatologist standard.
Benefits: Melasma and dark spots. Often used in cycles.
Common Products: Prescription creams or compounded blends.
Effective Concentration: Commonly 4% Rx.
Storage & Packaging: Opaque, airtight. Follow medical guidance.

Hydrators, Barrier Builders, and Moisturizers

Glycerin

Definition: Gold-standard humectant that binds water in skin.
Benefits: Immediate and long-lasting hydration, barrier support.
Common Products: Nearly all leave-ons and cleansers.
Effective Concentration: 3–10% typical. Higher can feel tacky.
Storage & Packaging: Very stable.

Hyaluronic Acid and Sodium Hyaluronate

Definition: Water-binding polymers in multiple molecular weights.
Benefits: Plumping hydration, elasticity support.
Common Products: Serums, moisturizers, masks.
Effective Concentration: 0.1–2% depending on MW blend.
Storage & Packaging: Stable. Keep sealed to prevent evaporation.

Polyglutamic Acid

Definition: Film-forming humectant polymer.
Benefits: Surface hydration and smoothness, complements HA.
Common Products: Serums, moisturizers, primers.
Effective Concentration: 0.1–1%.
Storage & Packaging: Stable.

Sodium PCA

Definition: Natural moisturizing factor component.
Benefits: Deep hydration and flexibility.
Common Products: Serums, moisturizers, mists.
Effective Concentration: 0.2–2%.
Storage & Packaging: Stable.

Urea

Definition: Humectant and mild keratolytic at higher levels.
Benefits: Hydration at 2–10%. Softens rough skin at 20–40%.
Common Products: Creams, foot care, hand creams.
Effective Concentration: 2–10% face, 20–40% body roughness.
Storage & Packaging: Stable. Avoid heat for high-%.

Betaine (Trimethylglycine)

Definition: Osmolyte that helps cells manage water balance.
Benefits: Hydration, soothing, reduces irritation from acids or surfactants.
Common Products: Serums, cleansers, moisturizers.
Effective Concentration: 1–5%.
Storage & Packaging: Stable.

Trehalose and Saccharide Isomerate

Definition: Water-binding sugars that cling to skin.
Benefits: Long-wear hydration, improved feel and elasticity.
Common Products: Serums, moisturizers.
Effective Concentration: Trehalose 1–5%. Saccharide isomerate 2–5%.
Storage & Packaging: Stable.

Panthenol (Pro-Vitamin B5)

Definition: Humectant with calming action.
Benefits: Reduces irritation, supports barrier, hydrates.
Common Products: Serums, moisturizers, masks, mists.
Effective Concentration: 1–5%.
Storage & Packaging: Stable.

Ceramides (NP, AP, EOP) + Cholesterol + Fatty Acids

Definition: Key lipids of the skin barrier.
Benefits: Repair and strengthen barrier, reduce TEWL.
Common Products: Moisturizers, barrier serums, cleansers.
Effective Concentration: Ceramides 0.5–3% total. Often paired with cholesterol ~0.5–1% and linoleic-rich oils.
Storage & Packaging: Stable when protected from heat.

Squalane

Definition: Stable, saturated lipid similar to skin’s sebum.
Benefits: Lightweight emollience, reduces moisture loss.
Common Products: Face oils, moisturizers, serums.
Effective Concentration: 5–100% depending on format.
Storage & Packaging: Very stable.

Caprylic/Capric Triglyceride (CCT)

Definition: Lightweight emollient derived from glycerin and coconut fractions.
Benefits: Soft feel, helps dissolve actives.
Common Products: Oils, creams, makeup.
Effective Concentration: 5–50% typical.
Storage & Packaging: Stable.

Fatty Alcohols (Cetyl, Cetearyl)

Definition: Waxy emollients and thickeners.
Benefits: Smooth, cushiony texture and barrier support.
Common Products: Creams, lotions, conditioners.
Effective Concentration: 1–10%.
Storage & Packaging: Stable.

Shea Butter and Other Butters (Mango, Cupuaçu)

Definition: Emollient lipids rich in stearic and oleic acids.
Benefits: Softening, reduces flaking, locks in moisture.
Common Products: Balms, creams, body care.
Effective Concentration: 2–20% face, higher for body.
Storage & Packaging: Keep cool to avoid melting.

Occlusives — Petrolatum, Mineral Oil, Lanolin, Dimethicone, Beeswax

Definition: Form a barrier to reduce water loss.
Benefits: Heal and protect dry, compromised skin.
Common Products: Ointments, balms, healing creams.
Effective Concentration: Petrolatum 30–100%, dimethicone 0.5–2%+.
Storage & Packaging: Stable. Tubes or jars are fine.

Soothers and Anti-Redness Agents

Allantoin

Definition: Keratoprotective soothing agent.
Benefits: Calms irritation and supports healing feel.
Common Products: Creams, serums, mists.
Effective Concentration: 0.2–0.5%.
Storage & Packaging: Stable.

Bisabolol

Definition: Anti-irritant from chamomile.
Benefits: Soothes redness, enhances penetration of some actives.
Common Products: Serums, creams, after-sun.
Effective Concentration: 0.1–1%.
Storage & Packaging: Protect from light.

Centella Asiatica (Madecassoside, Asiaticoside)

Definition: Botanical complex with well-known calming action.
Benefits: Redness, barrier support, post-procedure comfort.
Common Products: Serums, creams, masks.
Effective Concentration: Standardized actives often 0.1–0.5% each.
Storage & Packaging: Opaque preferred.

Beta-Glucan

Definition: Polysaccharide from oats or fungi with film-forming hydration.
Benefits: Soothing, plumping hydration, supports barrier.
Common Products: Serums, creams, masks.
Effective Concentration: 0.1–1%.
Storage & Packaging: Stable.

Colloidal Oatmeal

Definition: Finely milled oats with beta-glucans and avenanthramides.
Benefits: Itch relief, barrier support, soothing.
Common Products: Creams, body lotions, eczema care.
Effective Concentration: 0.5–2%.
Storage & Packaging: Keep dry and sealed.

Aloe Vera

Definition: Hydrating, soothing botanical gel.
Benefits: Cooling, calming, light hydration.
Common Products: Gels, lotions, mists.
Effective Concentration: Varies by extract. Look for aloe high on the list.
Storage & Packaging: Refrigerate pure gels. Stabilized products are shelf-stable.

Ectoin

Definition: Extremolyte that protects cells from environmental stress.
Benefits: Redness, dehydration from heat or pollution, barrier support.
Common Products: Serums, moisturizers, after-sun.
Effective Concentration: 0.5–2%.
Storage & Packaging: Stable, opaque preferred.

Antioxidants and Anti-Glycation

Vitamin E (Tocopherol, Tocopheryl Acetate)

Definition: Lipid-soluble antioxidant and skin protectant.
Benefits: Synergizes with vitamin C, supports barrier.
Common Products: Serums, oils, creams, sunscreens.
Effective Concentration: 0.5–1% tocopherol, 1–2% tocopheryl acetate.
Storage & Packaging: Protect from light and air.

Ferulic Acid

Definition: Phenolic antioxidant that stabilizes vitamin C and E.
Benefits: Photoprotection, brightening synergy.
Common Products: Antioxidant serums.
Effective Concentration: 0.5–1%.
Storage & Packaging: Opaque, airless.

Resveratrol

Definition: Polyphenol from grapes and knotweed.
Benefits: Antioxidant support, tone evenness.
Common Products: Serums, night creams.
Effective Concentration: 0.1–1%.
Storage & Packaging: Opaque, avoid heat.

Coenzyme Q10 (Ubiquinone)

Definition: Lipid-soluble antioxidant in mitochondrial membranes.
Benefits: Photoprotection, firmness support.
Common Products: Creams, serums, eye products.
Effective Concentration: 0.1–1%.
Storage & Packaging: Opaque, oil base ideal.

Idebenone

Definition: Synthetic analog of CoQ10 with strong antioxidant action.
Benefits: Photoaging markers, tone, texture.
Common Products: Serums, creams.
Effective Concentration: 0.5–1%.
Storage & Packaging: Opaque, airless.

Green Tea (EGCG)

Definition: Catechin-rich antioxidant.
Benefits: Redness, oil control, UV-stress support.
Common Products: Serums, toners, sunscreens.
Effective Concentration: Standardized EGCG often 0.1–2%.
Storage & Packaging: Opaque, cool storage.

Carnosine

Definition: Dipeptide that helps counter glycation.
Benefits: Firmness and tone over time, pollution protection.
Common Products: Serums, moisturizers.
Effective Concentration: 0.2–1%.
Storage & Packaging: Opaque, avoid heat.

Ergothioneine

Definition: Antioxidant amino acid from fungi.
Benefits: Photoprotection and antioxidant support.
Common Products: Serums, moisturizers.
Effective Concentration: 0.01–0.1% typical.
Storage & Packaging: Opaque.

Peptides and Growth Factors

Matrixyl Family (Palmitoyl Pentapeptide-4, Palmitoyl Tripeptide-1, -7)

Definition: Signal peptides that cue collagen and ECM support.
Benefits: Firmness, fine lines, resilience.
Common Products: Serums, creams, eye products.
Effective Concentration: Often 2–3% of peptide blend.
Storage & Packaging: Stable. Avoid heat.

Acetyl Hexapeptide-8 (Argireline)

Definition: Neuro-peptide that targets expression lines at the surface.
Benefits: Softens look of dynamic lines with consistent use.
Common Products: Serums, eye products.
Effective Concentration: 5–10% in many OTC products.
Storage & Packaging: Stable. Keep cool.

Copper Peptides (GHK-Cu)

Definition: Peptide complexed with copper ions.
Benefits: Firmness, even tone, wound-care heritage.
Common Products: Serums, creams.
Effective Concentration: 0.05–0.3% active GHK-Cu.
Storage & Packaging: Opaque, avoid strong acids in same routine.

EGF and Growth Factors (sh-Oligopeptide-1, sh-Polypeptide-1)

Definition: Lab-grown signaling proteins and peptides.
Benefits: Smoothness, bounce, post-procedure support.
Common Products: Serums, ampoules, masks.
Effective Concentration: Low percentages. Look for reputable suppliers.
Storage & Packaging: Airless, opaque. Often best kept cool.

Dipeptide Diaminobutyroyl Benzylamide Diacetate (Syn-Ake)

Definition: Peptide that mimics a muscle-relaxing protein fragment.
Benefits: Softens the look of expression lines.
Common Products: Serums, eye creams.
Effective Concentration: ~1–4% in blends.
Storage & Packaging: Stable. Avoid heat.

Acne-Focused Actives

Benzoyl Peroxide

Definition: Antibacterial and keratolytic.
Benefits: Inflammatory acne, reduces C. acnes and clogs.
Common Products: Gels, cleansers, leave-on creams.
Effective Concentration: 2.5–5% face, up to 10% body. Lower is often as effective with less irritation.
Storage & Packaging: Can bleach fabrics. Opaque tubes.

Salicylic Acid

See: BHA above.

Sulfur

Definition: Keratolytic with antibacterial properties.
Benefits: Acne and seborrheic concerns, spot treatment.
Common Products: Masks, soaps, spot gels.
Effective Concentration: 3–10%.
Storage & Packaging: Stable. Characteristic odor.

Zinc PCA / Zinc Gluconate

Definition: Oil-modulating mineral salts.
Benefits: Sebum control, redness support, acne-prone skin.
Common Products: Serums, toners, moisturizers.
Effective Concentration: 0.1–1%.
Storage & Packaging: Stable.

Tea Tree Oil (Melaleuca Alternifolia)

Definition: Essential oil with antibacterial action.
Benefits: Mild acne support. Can irritate.
Common Products: Spot treatments, cleansers.
Effective Concentration: ~5% in gels. Always patch test.
Storage & Packaging: Dark glass. Keep cool. Avoid eye area.

Sunscreen Filters and Boosters

Mineral Filters — Zinc Oxide, Titanium Dioxide

Definition: Inorganic UV filters that reflect and scatter UV.
Benefits: Broad-spectrum protection, sensitive-skin friendly.
Common Products: Sunscreens, tints, baby formulas.
Effective Concentration: Determined by the formula. Choose SPF 30+ broad spectrum.
Storage & Packaging: Keep sealed, avoid heat and sun exposure of the bottle.

Organic Filters — Avobenzone, Octisalate, Octocrylene, Homosalate, Oxybenzone

Definition: Organic molecules that absorb UV and dissipate it as heat.
Benefits: Broad UV coverage when properly combined.
Common Products: Sunscreens, many lotions and sprays.
Effective Concentration: Formula-dependent. Look for SPF 30+ broad spectrum.
Storage & Packaging: Keep out of hot cars or direct sun. Reapply every 2 hours outdoors.

New-Gen EU/Asia Filters — Tinosorb S/M, Uvinul A Plus, Uvinul T 150

Definition: Modern filters with strong UVA stability (not yet approved in the U.S.).
Benefits: Excellent photostability and cosmetic elegance.
Common Products: EU and Asian sunscreens.
Effective Concentration: Formula-dependent. Choose SPF 50 PA++++ for strong UVA.
Storage & Packaging: As above.

Antioxidant Boosters — Vitamin E, Ferulic, Resveratrol, Licochalcone A

Definition: Molecules that reduce UV-induced oxidative stress.
Benefits: Support sunscreen performance and after-sun recovery.
Common Products: Sunscreens and morning serums.
Effective Concentration: See individual entries.
Storage & Packaging: Opaque preferred.

Cleansing and Supporting Ingredients

Surfactants — Sodium Cocoyl Isethionate, Coco-Betaine, Decyl Glucoside

Definition: Cleansing agents that lift oils and debris.
Benefits: Clean skin without stripping if chosen well.
Common Products: Cleansers, shampoos, body washes.
Effective Concentration: Varies by system. Gentle blends are best for face.
Storage & Packaging: Stable.

Micellar Waters — Poloxamers

Definition: Mild surfactant polymers that trap makeup and dirt.
Benefits: No-rinse makeup removal.
Common Products: Micellar waters.
Effective Concentration: System-dependent.
Storage & Packaging: Stable.

Solvents and Penetration Aids — Propanediol, Propylene Glycol, Alcohol Denat.

Definition: Help dissolve actives and enhance penetration.
Benefits: Improve delivery and texture. Alcohol can be drying at high levels.
Common Products: Serums, sprays, gels.
Effective Concentration: Few to several percent depending on role.
Storage & Packaging: Stable. Close caps tightly.

Chelators — Disodium EDTA, Tetrasodium Glutamate Diacetate

Definition: Bind metal ions to stabilize formulas.
Benefits: Improve preservative and antioxidant performance.
Common Products: Most water-based products.
Effective Concentration: 0.05–0.2%.
Storage & Packaging: Stable.

Preservatives and Stabilizers

Phenoxyethanol

Definition: Broad-spectrum preservative.
Benefits: Prevents microbial growth in water-based products.
Common Products: Most leave-ons and cleansers.
Effective Concentration: Up to 1% typical.
Storage & Packaging: Stable.

Parabens (Methyl-, Propyl-, Butyl-)

Definition: Long-used preservatives with strong safety data at cosmetic levels.
Benefits: Reliable broad-spectrum protection.
Common Products: Many legacy and professional formulas.
Effective Concentration: ~0.1–0.3% each in blends.
Storage & Packaging: Stable.

Ethylhexylglycerin

Definition: Preservative booster and deodorizing humectant.
Benefits: Enhances other preservatives to reduce levels needed.
Common Products: Serums, creams, deodorants.
Effective Concentration: 0.3–1%.
Storage & Packaging: Stable.

Sodium Benzoate + Potassium Sorbate

Definition: Acidic pH preservatives often used together.
Benefits: Yeast and mold control in natural-leaning formulas.
Common Products: Toners, gels.
Effective Concentration: ~0.2–1% combined. Needs low pH.
Storage & Packaging: Stable when pH is right.

Benzyl Alcohol, Dehydroacetic Acid

Definition: Preservative system often used in “eco” formulas.
Benefits: Broad coverage when paired.
Common Products: Serums, creams.
Effective Concentration: System-dependent.
Storage & Packaging: Stable.

Botanicals and Miscellaneous Actives

Niacinamide (Vitamin B3)

Definition: Versatile vitamin that supports many skin functions.
Benefits: Redness, oil balance, pore look, barrier, brightening with NAG.
Common Products: Serums, toners, moisturizers.
Effective Concentration: 2–5% common, up to 10% in some products.
Storage & Packaging: Very stable.

Caffeine

Definition: Vasoconstrictor and antioxidant.
Benefits: Temporary de-puff and tone around eyes, antioxidant support.
Common Products: Eye serums, body firming gels.
Effective Concentration: 0.3–1%.
Storage & Packaging: Opaque preferred.

Arnica

Definition: Botanical for post-procedure comfort.
Benefits: Soothing feel on bruised or tender areas.
Common Products: Gels, creams.
Effective Concentration: Extract-dependent.
Storage & Packaging: Protect from light. Patch test.

Probiotics, Prebiotics, Postbiotics (Bifida Ferment Lysate, Lactobacillus Ferments)

Definition: Non-living lysates and ferments that signal calmer, resilient skin.
Benefits: Barrier support and reduced reactivity.
Common Products: Serums, essences, moisturizers.
Effective Concentration: Often 5–20% ferment in water phase. Varies widely.
Storage & Packaging: Opaque, avoid heat.

Witch Hazel

Definition: Astringent botanical. Alcohol-free versions are gentler.
Benefits: Temporary pore-tightening feel and oil control.
Common Products: Toners, mists.
Effective Concentration: Varies. Choose alcohol-free for sensitive skin.
Storage & Packaging: Opaque preferred.

DMAE

Definition: Amino alcohol sometimes used for firming appearance.
Benefits: Temporary tightening feel. Evidence is mixed.
Common Products: Serums, creams.
Effective Concentration: ~3% common.
Storage & Packaging: Opaque. Patch test.

Licorice, Chamomile, Green Tea, Calendula Blends

Definition: Soothing antioxidant botanicals used together for synergy.
Benefits: Redness relief, antioxidant support.
Common Products: Serums, mists, moisturizers.
Effective Concentration: Extract-dependent.
Storage & Packaging: Opaque, cool storage.

Fragrance and Potential Irritants

Fragrance/Parfum and Essential Oils

Definition: Scent components, natural or synthetic.
Benefits: Sensorial experience only. No skincare benefit.
Common Products: Many.
Effective Concentration: Not applicable.
Storage & Packaging: Dark glass ideal for pure oils.

Common Allergen Markers — Linalool, Limonene, Citral, Coumarin, Geraniol, Eugenol

Definition: Fragrance allergens that must be listed in many regions.
Benefits: None for skin health.
Common Products: Scented products.
Effective Concentration: Not applicable.
Storage & Packaging: Avoid if sensitive.

How to Judge a Formula Quickly

Percent and pH: For acids and vitamin C, percent and pH matter. For retinoids and many peptides, percent is helpful but not the whole story.
Packaging: Opaque and airless for light- and air-sensitive actives like LAA and retinoids.
Order on INCI list: Higher on the list usually means more of it, except for actives effective at low percentages.
Routine fit: Strong actives pair best with SPF daily and gentle cleansers and moisturizers.

Storage Cheat Sheet

Refrigerate or keep very cool: L-ascorbic acid serums, EGF/growth-factor serums (per label).
Keep in the dark, airless if possible: Retinoids, vitamin C, ferulic mixes, antioxidants.
Shelf-stable with normal care: Niacinamide, ceramides, squalane, glycerin, panthenol.

Safety and Use

Patch test new actives. Introduce one at a time.
Daytime: sunscreen every day, reapply outdoors every 2 hours.
Avoid combining many strong actives at once if your barrier is sensitive.

This glossary summarizes typical consumer-use guidance. Individual formulas and skin needs vary. When in doubt, consult your dermatologist.

Skincare Ingredient Glossary (Expanded A–Z)

This supplement builds on the Master Glossary, adding additional ingredients across categories to create a near-exhaustive consumer reference.

A

Acmella Oleracea (Spilanthol)

Definition: Plant extract sometimes called “natural Botox.”
Benefits: Temporary muscle-relaxing feel, smoothing expression lines.
Common Products: Serums, creams.
Effective Concentration: 2–5% extract.
Storage & Packaging: Opaque preferred.

Adenosyl Methionine (SAMe)

Definition: Coenzyme with antioxidant and methylation support roles.
Benefits: Antioxidant, barrier support.
Common Products: Serums, niche creams.
Effective Concentration: Varies; not widely standardized.
Storage & Packaging: Opaque, cool.

Alkaline Neutralizers (Triethanolamine, Tromethamine)

Definition: pH adjusters.
Benefits: Not active for skin but critical for formula stability.
Common Products: Most emulsions.
Effective Concentration: <1% typical.
Storage & Packaging: Stable.

B

Bakuchiol

Definition: Plant-derived antioxidant used as a retinol alternative.
Benefits: Texture, tone, antioxidant support.
Common Products: Serums, oils.
Effective Concentration: 0.5–1%.
Storage & Packaging: Protect from light.

Beta-Carotene

Definition: Provitamin A carotenoid.
Benefits: Antioxidant, colorant, mild photoprotection.
Common Products: Oils, serums.
Effective Concentration: Trace levels to 1%.
Storage & Packaging: Dark, airtight.

C

Carnosic Acid (Rosemary Extract)

Definition: Antioxidant from rosemary.
Benefits: Preservative booster, anti-oxidative.
Common Products: Oils, serums, natural products.
Effective Concentration: 0.05–0.5%.
Storage & Packaging: Opaque, cool.

Chitosan

Definition: Biopolymer from shells or fungi.
Benefits: Film-former, wound-healing support.
Common Products: Masks, sprays.
Effective Concentration: 0.1–1%.
Storage & Packaging: Opaque.

Copper PCA

Definition: Mineral complex with sebum-modulating properties.
Benefits: Oil regulation, antioxidant synergy.
Common Products: Serums, toners.
Effective Concentration: 0.05–0.5%.
Storage & Packaging: Stable.

D

Dexpanthenol

Definition: Active form of panthenol.
Benefits: Stronger barrier repair and hydration support.
Common Products: Serums, creams.
Effective Concentration: 1–5%.
Storage & Packaging: Stable.

Dimethyl Isosorbide (DMI)

Definition: Solvent and penetration enhancer.
Benefits: Improves stability and delivery of actives like ascorbic acid.
Common Products: Serums.
Effective Concentration: 1–5%.
Storage & Packaging: Stable, airtight.

E

Ellagic Acid

Definition: Polyphenolic antioxidant.
Benefits: Brightening, antioxidant support.
Common Products: Serums, creams.
Effective Concentration: 0.1–1%.
Storage & Packaging: Opaque, avoid heat.

Evening Primrose Oil (High Gamma-Linolenic Acid)

Definition: Botanical oil rich in GLA.
Benefits: Barrier repair, soothing dryness.
Common Products: Oils, creams.
Effective Concentration: 2–20%.
Storage & Packaging: Dark, airtight.

F

Fullerene (C60)

Definition: Carbon molecule antioxidant.
Benefits: Potent free radical scavenger.
Common Products: High-tech serums, creams.
Effective Concentration: ~0.01–0.05%.
Storage & Packaging: Opaque, airless.

G

Gamma-Linolenic Acid (GLA)

Definition: Omega-6 fatty acid.
Benefits: Soothes dryness and barrier dysfunction.
Common Products: Oils (evening primrose, borage).
Effective Concentration: 1–10%.
Storage & Packaging: Dark, airtight.

Galactomyces Ferment Filtrate

Definition: Yeast ferment filtrate.
Benefits: Brightening, hydration, texture improvement.
Common Products: Essences, serums.
Effective Concentration: 50–100% as base.
Storage & Packaging: Opaque, avoid heat.

H

Hesperidin

Definition: Citrus flavonoid.
Benefits: Vascular support, brightening.
Common Products: Eye creams, serums.
Effective Concentration: 0.1–1%.
Storage & Packaging: Opaque.

Humic Acid / Fulvic Acid

Definition: Mineral-rich organic acids.
Benefits: Anti-inflammatory, barrier support.
Common Products: Mists, serums.
Effective Concentration: 0.1–1%.
Storage & Packaging: Dark, airtight.

I

Isoflavones (Soy Extract)

Definition: Plant estrogens.
Benefits: Firmness, tone evenness.
Common Products: Serums, creams.
Effective Concentration: 0.5–2% standardized extract.
Storage & Packaging: Opaque.

J

Jojoba Oil (Simmondsia Chinensis)

Definition: Liquid wax ester close to human sebum.
Benefits: Balancing, non-comedogenic, emollient.
Common Products: Oils, creams, balms.
Effective Concentration: 5–100%.
Storage & Packaging: Dark, airtight.

K

Kojic Acid Dipalmitate

Definition: Stable derivative of kojic acid.
Benefits: Brightening, more stable than kojic acid.
Common Products: Serums, creams.
Effective Concentration: 1–3%.
Storage & Packaging: Opaque, cool.

L

Lactobacillus Ferments (Postbiotics)

Definition: Fermented lysates and filtrates.
Benefits: Barrier and microbiome support.
Common Products: Essences, serums, moisturizers.
Effective Concentration: 5–20% blend.
Storage & Packaging: Opaque.

Lipoic Acid

Definition: See Alpha-Lipoic Acid.

M

Magnesium Ascorbyl Phosphate (MAP)

Definition: Stable vitamin C derivative.
Benefits: Brightening, antioxidant.
Common Products: Serums, creams.
Effective Concentration: 5–10%.
Storage & Packaging: Opaque, stable.

Moringa Oil

Definition: Lightweight, oleic-rich oil.
Benefits: Emollient, antioxidant.
Common Products: Oils, creams.
Effective Concentration: 5–100%.
Storage & Packaging: Dark, airtight.

N

Niacinamide (Vitamin B3)

Definition: Versatile vitamin.
Benefits: Redness, barrier support, brightening.
Common Products: Serums, toners, creams.
Effective Concentration: 2–10%.
Storage & Packaging: Stable.

O

Oryzanol (Gamma Oryzanol)

Definition: Antioxidant from rice bran.
Benefits: Brightness, barrier comfort.
Common Products: Oils, creams.
Effective Concentration: 0.5–2%.
Storage & Packaging: Dark, airtight.

P

Palmitoyl Tripeptide-38 (Matrixyl Synthe’6)

Definition: Signal peptide.
Benefits: Firmness, wrinkle reduction.
Common Products: Serums, creams.
Effective Concentration: 2–3% blend.
Storage & Packaging: Opaque.

Peony Extract (Paeonia)

Definition: Botanical antioxidant.
Benefits: Brightening, soothing.
Common Products: Serums, creams.
Effective Concentration: 1–5% extract.
Storage & Packaging: Opaque.

Q

Quillaja Saponaria (Soap Bark)

Definition: Natural foaming agent.
Benefits: Mild cleansing support.
Common Products: Cleansers, shampoos.
Effective Concentration: 1–5%.
Storage & Packaging: Stable.

R

Rhamnose

Definition: Sugar with signaling properties.
Benefits: Redness, firmness support.
Common Products: Serums, creams.
Effective Concentration: 5–10%.
Storage & Packaging: Opaque.

S

Sea Buckthorn Oil (Hippophae Rhamnoides)

Definition: Bright orange oil rich in carotenoids.
Benefits: Barrier repair, antioxidant.
Common Products: Oils, balms.
Effective Concentration: 5–100%.
Storage & Packaging: Dark glass.

Shikonin (Lithospermum Root Extract)

Definition: Red pigment compound.
Benefits: Anti-inflammatory, soothing.
Common Products: Balms, ointments.
Effective Concentration: 0.01–0.1%.
Storage & Packaging: Opaque.

T

Tasmannia Lanceolata (Tasmanian Pepperberry)

Definition: Botanical extract rich in polygodial.
Benefits: Soothing, reduces irritation from acids.
Common Products: Serums, toners.
Effective Concentration: 0.1–1%.
Storage & Packaging: Opaque.

Tripeptides (e.g., Tripeptide-1)

Definition: Small signal peptides.
Benefits: Collagen and ECM support.
Common Products: Serums, eye creams.
Effective Concentration: 0.5–2% blends.
Storage & Packaging: Opaque.

U

Ursolic Acid

Definition: Triterpenoid compound from plants.
Benefits: Anti-inflammatory, anti-glycation.
Common Products: Serums, creams.
Effective Concentration: 0.1–1%.
Storage & Packaging: Opaque.

V

Vanillic Acid

Definition: Phenolic acid.
Benefits: Antioxidant support.
Common Products: Serums, creams.
Effective Concentration: 0.1–0.5%.
Storage & Packaging: Opaque.

W

White Willow Bark (Salix Alba)

Definition: Botanical source of salicylates.
Benefits: Mild exfoliation; not equivalent to pure SA.
Common Products: Toners, serums.
Effective Concentration: Extract-dependent.
Storage & Packaging: Opaque.

X

Xylitol

Definition: Sugar alcohol.
Benefits: Hydration, supports microbiome balance.
Common Products: Serums, creams, mists.
Effective Concentration: 1–5%.
Storage & Packaging: Stable.

Y

Yeast Extracts (Saccharomyces Lysate)

Definition: Ferments/lysates with vitamins, peptides.
Benefits: Barrier support, brightening, smoothing.
Common Products: Essences, serums.
Effective Concentration: 5–20%.
Storage & Packaging: Opaque.

Z

Zinc PCA

Definition: Zinc salt with PCA.
Benefits: Oil regulation, barrier comfort.
Common Products: Serums, toners.
Effective Concentration: 0.1–1%.
Storage & Packaging: Stable.

This expanded glossary supplements the Master Glossary. Each entry provides consumer-level clarity.