Index · Ingredients
Every ingredient, graded honestly.
We score ingredients on the strength of the evidence behind their claims, not on hype, packaging, or what's trending. Each entry below links to a full brief: mechanism, evidence, concentration ranges, pairings, and the products we'd actually buy.
Ingredient Pairing Checker
Select two ingredients to verify clinical compatibility and synergies.
- Ingredient · Synthetic Retinoid · AdapaleneTier AAdapalene
Prescription-grade acne care without a prescription.
Used in4 concerns1 routines
Paired in5 briefs
03 / 28Filed 17 APR 2026 - Ingredient · Hydroquinone glucoside · Alpha arbutinTier BAlpha arbutin
Hydroquinone with the brakes on — and that is the point.
Used in2 concerns1 routines
Paired in3 briefs
13 / 28Filed 13 APR 2026 - Ingredient · Dicarboxylic acid · AzelaicTier AAzelaic acid
Three jobs at once. Quietly underused.
Used in7 concerns1 routines
Paired in5 briefs
04 / 28Filed 17 APR 2026 - Ingredient · Meroterpene · BakuchiolTier BBakuchiol
One small RCT. Two billion marketing dollars.
Used in1 concerns0 routines
Paired in3 briefs
19 / 28Filed 18 APR 2026 - Ingredient · Modern long-UVA filter · Tinosorb STier ABemotrizinol
The best chemical filter on Earth. Just not in America.
Used in0 concerns0 routines
Paired in2 briefs
22 / 28Filed 10 APR 2026 - Ingredient · Antimicrobial · BPOTier ABenzoyl peroxide
Kills the bacterium without breeding resistance. Bleaches your towels regardless.
Used in2 concerns1 routines
Paired in3 briefs
25 / 28Filed 11 APR 2026 - Ingredient · Botanical · Centella · 'Cica'Tier BCentella asiatica
The 'cica' in K-beauty — and its honest evidence floor.
Used in4 concerns0 routines
Paired in4 briefs
16 / 28Filed 15 APR 2026 - Ingredient · Sphingolipids · CeramidesTier ACeramides
The lipids your skin makes — until it doesn't.
Used in3 concerns4 routines
Paired in5 briefs
15 / 28Filed 14 APR 2026 - Ingredient · Peptide-metal complex · GHK-CuTier BCopper peptides
Promising biology, narrow application window.
Used in1 concerns1 routines
Paired in2 briefs
19 / 28Filed 16 APR 2026 - Ingredient · Cell-derived vesicles · Cosmetic exosomesTier DExosomes (cosmetic)
Real biology, premature product. The most expensive maybe in skincare.
Used in0 concerns0 routines
Paired in1 brief
27 / 28Filed 20 APR 2026 - Ingredient · Alpha-hydroxy Acid · GlycolicTier AGlycolic acid
The smallest AHA, with the longest data tail.
Used in4 concerns0 routines
Paired in3 briefs
09 / 28Filed 12 APR 2026 - Ingredient · Glycosaminoglycan · HyaluronicTier AHyaluronic acid
Real, useful, and comprehensively oversold.
Used in1 concerns0 routines
Paired in4 briefs
14 / 28Filed 14 APR 2026 - Ingredient · Antioxidant · L-ascorbic acid (vitamin C)Tier AL-ascorbic acid
The most-bought antioxidant. The most-misused, too.
Used in6 concerns2 routines
Paired in4 briefs
03 / 28Filed 16 APR 2026 - Ingredient · Alpha-hydroxy Acid · LacticTier ALactic acid
Glycolic's gentler cousin — with a hydration bonus.
Used in2 concerns0 routines
Paired in2 briefs
10 / 28Filed 13 APR 2026 - Ingredient · Alpha-hydroxy Acid · MandelicTier BMandelic acid
The biggest AHA molecule — for the most reactive skin.
Used in2 concerns0 routines
Paired in2 briefs
11 / 28Filed 13 APR 2026 - Ingredient · Vitamin B family · NiacinamideTier ANiacinamide
The boring multi-tasker that earns its place.
Used in6 concerns5 routines
Paired in19 briefs
02 / 28Filed 14 APR 2026 - Ingredient · Pro-vitamin B5 · PanthenolTier BPanthenol
The quiet supporting cast in nearly every barrier cream.
Used in2 concerns1 routines
Paired in5 briefs
17 / 28Filed 15 APR 2026 - Ingredient · Bee resin · PropolisTier CPropolis
Useful, niche, and worth knowing your allergens.
Used in0 concerns0 routines
Paired in1 brief
24 / 28Filed 18 APR 2026 - Ingredient · Retinoid · RetinolTier ARetinol
The over-the-counter retinoid that earns the comparison.
Used in3 concerns0 routines
Paired in6 briefs
02 / 28Filed 16 APR 2026 - Ingredient · Beta-hydroxy Acid · SalicylicTier ASalicylic acid
Oil-soluble, pore-soluble, and quietly indispensable.
Used in2 concerns2 routines
Paired in4 briefs
08 / 28Filed 12 APR 2026 - Ingredient · Peptides · Signal classTier BSignal peptides
Slow, modest, plausible. Three honest words.
Used in1 concerns0 routines
Paired in4 briefs
18 / 28Filed 16 APR 2026 - Ingredient · Biofiltrate · Snail secretionTier CSnail mucin
K-beauty's biggest export — with a real but modest signal.
Used in0 concerns0 routines
Paired in2 briefs
23 / 28Filed 18 APR 2026 - Ingredient · Antimicrobial · Elemental sulphurTier BSulphur
Old-school, still useful, smells terrible.
Used in0 concerns0 routines
Paired in1 brief
26 / 28Filed 11 APR 2026 - Ingredient · Lysine analogue · TranexamicTier ATranexamic acid
The pigment fix retinoids quietly miss.
Used in4 concerns1 routines
Paired in4 briefs
12 / 28Filed 11 APR 2026 - Ingredient · Anti-aging & fine linesTier ATretinoin
all-trans retinoic acid · C20H28O2 · MW 300.4 Da
Used in9 concerns1 routines
Paired in3 briefs
001 / 30Filed 18 APR 2026 - Ingredient · Photoprotection · UV filter overviewTier AUV filters
The one non-negotiable in the entire library.
Used in0 concerns0 routines
Paired in3 briefs
20 / 28Filed 10 APR 2026 - Ingredient · Mineral filter · Zinc oxideTier AZinc oxide
Broad-spectrum, photostable, and the cast you can live with.
Used in0 concerns0 routines
Paired in2 briefs
21 / 28Filed 10 APR 2026