Frequently Asked Questions

We compare full INCI ingredient lists using four factors: Jaccard similarity (shared ingredients), active ingredient overlap, INCI order correlation (concentration indicators), and functional role similarity. A product needs at least 3 shared ingredients and a composite score above 15% to qualify as a dupe.

Our product database comes from Open Beauty Facts (an open-source cosmetics database maintained by thousands of contributors worldwide) and publicly available product listings from major retailers. We do not scrape private or paywalled data.

Formula quality is scored 0-100 based on: number of proven active ingredients (40%), ingredient count sweet spot (20%), active ingredient position in the INCI list (20%), and ingredient diversity (20%). This is a formula complexity metric, not a clinical efficacy score.

We track 38 known irritants (fragrance allergens, drying alcohols, formaldehyde releasers, harsh surfactants) and score products 0-100. Higher = fewer potential irritants. 'Potentially irritating' does not mean 'dangerous' - most flagged ingredients are safe for most people.

No. GetDupe is a formula comparison tool. It helps you understand what's in your products and find similar alternatives. It is not medical or dermatological advice. Always patch test new products and consult a dermatologist for skin concerns.

No. We do not use affiliate links and we do not earn commissions on product purchases. We have no financial incentive to recommend one product over another.

Yes! If a product is missing from our database, you can submit it with its ingredient list and we'll add it to our analysis.

Ingredient lists don't include exact percentages. A product listing niacinamide 5th vs 15th tells us something about concentration, but not the exact %. Our scores are directionally correct for comparing formulas, but two products with similar ingredients may still perform differently due to concentration differences, formulation techniques, and delivery systems.