Ingredient education

Skincare Ingredient Glossary

Every active we carry, explained by our skincare experts, with the products that use it.

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Hyaluronic acid

Best for

Dehydration, Plumping, Fine lines, All skin types

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Niacinamide

Best for

Large pores, Redness, Oil control, Dark spots, Skin barrier

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Peptides

Best for

Fine lines, Firmness, Collagen support, Sensitive skin

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The full glossary

71 entries, A to Z. Every one reviewed by our licensed skincare professionals.

AHA (alpha hydroxy acids)alpha hydroxy acids, glycolic acid, lactic acid, mandelic acid Dull skin, Rough texture, Fine lines, Dark spots Algae extractseaweed extract, kelp, spirulina, marine algae Dehydrated skin, Dull skin, Antioxidant support, Sensitive skin Aloe veraaloe barbadensis, aloe leaf juice, aloe gel Sunburn, Redness, Irritated skin, Light hydration Antioxidantsfree-radical fighters, vitamin C, vitamin E, ferulic acid Sun damage, Early aging, Dullness, Pollution protection Arbutinalpha arbutin, beta arbutin, bearberry extract Dark spots, Uneven tone, Melasma, Post-acne marks Arnicaarnica montana, mountain arnica, leopard's bane Bruising, Swelling, Post-procedure care, Sore spots Azelaic acidAzA, azelaic, dicarboxylic acid Rosacea, Acne, Melasma, Redness, Post-acne marks
Bakuchiolplant-based retinol alternative, babchi extract, psoralea corylifolia Fine lines, Sensitive skin, Uneven tone, Retinol alternative BemotrizinolBEMT, Tinosorb S, bis-ethylhexyloxyphenol methoxyphenyl triazine Broad-spectrum protection, UVA protection, Sensitive skin, Daily SPF Benzoyl peroxideBPO, BP Acne, Inflamed pimples, Body breakouts, Oily skin BHA (beta hydroxy acid)beta hydroxy acid, salicylic acid Clogged pores, Blackheads, Oily skin, Breakouts Biotinvitamin B7, vitamin H Thinning hair, Hair growth, Brittle nails, Hair strength
Caffeinecoffee extract, coffea arabica, guarana Puffiness, Dark circles, Tired eyes, Antioxidant support Centella asiaticacica, gotu kola, tiger grass, madecassoside Redness, Sensitive skin, Barrier repair, Irritation Ceramidesceramide NP, ceramide AP, ceramide EOP, skin lipids Dry skin, Eczema, Skin barrier, Sensitive skin, Retinol dryness Chemical sunscreen filtersavobenzone, octinoxate, octocrylene, homosalate, octisalate, organic filters Daily UV protection, Lightweight SPF, No white cast, Under makeup Claykaolin, bentonite, charcoal, French green clay Oily skin, Congestion, Blackheads, Large pores Collagenmarine collagen, collagen peptides, hydrolyzed collagen Firmness, Elasticity, Fine lines, Aging skin Copper peptidesGHK-Cu, copper tripeptide-1, blue peptides Firmness, Fine lines, Skin repair, Thinning hair CysteamineCyspera, cysteamine hydrochloride Melasma, Stubborn dark spots, Hyperpigmentation, Uneven tone
Defensinsdefensin peptides, alpha-defensin 5, beta-defensin 3, Age-Repair Defensins Aging skin, Fine lines, Large pores, Uneven texture DNA repair enzymesphotolyase, endonuclease, DNA repairsomes Sun damage, Rough sun-damaged patches, Aging skin, After-sun care
Ectoinectoine Sensitive skin, Pollution protection, Dehydration, Redness Exosomesexosome serum, extracellular vesicles, secretome Post-procedure repair, Aging skin, Redness, Uneven texture Enzymespapain, bromelain, pumpkin enzyme, enzyme exfoliants Gentle exfoliation, Sensitive skin, Dull skin, Rough texture
Ferulic acidhydroxycinnamic acid, C E Ferulic Sun damage, Dark spots, Fine lines, Boosting vitamin C Fragranceparfum, essential oils, fragrance-free, unscented Sensitive skin, Rosacea, Eczema, Skin allergies
Glyceringlycerol, vegetable glycerin Dry skin, Dehydrated skin, Sensitive skin, Skin barrier Glycolic acidAHA, alpha hydroxy acid, hydroxyacetic acid Rough texture, Dullness, Fine lines, Dark spots Green teaEGCG, camellia sinensis leaf extract, green tea polyphenols Redness, Oily skin, Antioxidant protection, Acne-prone skin Growth factorsEGF, TNS, human growth factors, epidermal growth factor Aging skin, Fine lines and wrinkles, Firmness, Post-procedure recovery
Heparan sulfate analog (HSA)HSA, Sente HSA, low molecular weight heparan sulfate Dry skin, Dehydration, Aging skin, Redness Humectantswater-binding ingredients, hyaluronic acid, glycerin, panthenol Dehydrated skin, Dry skin, Dullness, Tight-feeling skin Hyaluronic acidHA, sodium hyaluronate, hyaluronan Dehydration, Plumping, Fine lines, All skin types HydroquinoneHQ Melasma, Dark spots, Hyperpigmentation, Uneven tone
Iron oxidestinted mineral pigments, CI 77491, CI 77492, CI 77499 Melasma, Dark spots, Visible light protection, Deeper skin tones
Keratinhydrolyzed keratin, keratin protein Damaged hair, Frizz, Breakage, Hair strength Kojic acidkojic dipalmitate Dark spots, Melasma, Uneven tone, Post-acne marks
Lactic acidAHA, alpha hydroxy acid, sodium lactate Dry skin, Gentle exfoliation, Rough texture, Dullness
Mandelic acidAHA, alpha hydroxy acid, amygdalic acid Acne, Sensitive skin, Dark spots, Deeper skin tones MelatoninN-acetyl-5-methoxytryptamine, topical melatonin Overnight repair, Antioxidant support, Sun damage, Dull skin Mineral sunscreen filtersphysical sunscreen, zinc oxide, titanium dioxide, sunblock Sensitive skin, Acne-prone skin, Rosacea, Kids and pregnancy, Daily SPF
NAD+nicotinamide adenine dinucleotide, NMN, NAD Aging skin, Dullness, Skin repair, Longevity routines Niacinamidevitamin B3, nicotinamide Large pores, Redness, Oil control, Dark spots, Skin barrier
Oatoat, avena sativa, oat kernel extract, oat kernel flour Eczema, Itchy skin, Sensitive skin, Dry skin Occlusivespetrolatum, lanolin, dimethicone, slugging Very dry skin, Barrier repair, Slugging, Chapped lips
Panthenolvitamin B5, pro-vitamin B5, dexpanthenol Irritated skin, Dry skin, Redness, Skin healing Parabensmethylparaben, propylparaben, butylparaben, paraben-free Preservative concerns, Sensitive skin, Paraben allergy, Clean beauty shoppers PDRN / polynucleotidessalmon DNA, polynucleotides, polydeoxyribonucleotide, sodium DNA Skin repair, Elasticity, Post-procedure care, Dehydration PeptidesMatrixyl, tripeptides, signal peptides, palmitoyl pentapeptide Fine lines, Firmness, Collagen support, Sensitive skin

The glossary continues through Z, from ferulic acid to zinc oxide.

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Plain-language answers written by our licensed professionals, not marketing copy.

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Ingredient FAQs

Both are retinoids, vitamin A derivatives that speed up cell turnover. Retinol is available over the counter and converts to retinoic acid in the skin, so it works gradually with less irritation. Tretinoin is the prescription-strength form and acts faster, but often with more dryness and peeling.

Yes, most skin tolerates both when they are used at different times of day. Apply vitamin C in the morning under sunscreen and retinol at night. If you are new to actives, introduce them one at a time over two to three weeks.

Azelaic acid, niacinamide, hyaluronic acid, and mineral sunscreens are widely considered safe during pregnancy. Retinoids and hydroquinone should be paused until after nursing. Always confirm your routine with your OB or dermatologist.

Check the ingredient list for parfum, fragrance, or essential oils, usually near the end. Fragrance-free means no added scent, while unscented products may use a masking fragrance. Every product page on our site lists the full ingredient list so you can verify before you buy.

Mineral filters like zinc oxide and titanium dioxide sit on the skin and deflect UV, and they are the gentler pick for reactive skin. Chemical filters like avobenzone and bemotrizinol absorb UV and tend to feel lighter and clearer. Many modern formulas combine both.

Reviewed by our Medical Advisor

Dr. Ben Shatil