Independent breakdown
CosDNA
Limited valueTechnology: Online ingredient analysis — comedogenicity and irritation scoring
Plain English verdict
Limited value
CosDNA is widely used to check whether ingredients might be comedogenic (pore-clogging). The problem is its comedogenicity data source: rabbit ear assays conducted in the 1970s and 1980s that have been repeatedly criticised by dermatologists as poorly predictive of human acne. Multiple ingredients routinely flagged by CosDNA as high-comedogenicity are used safely by acne-prone individuals. The correlation between rabbit ear assay results and human comedogenicity is weak. Useful as an ingredient lookup tool; treat the comedogenicity scores — specifically the numerical ratings — with significant scepticism.
Worth it if you want
- +Looking up ingredient INCI names and general functions
- +As a starting point before cross-referencing with primary literature
Not worth it if
- −Making acne-trigger decisions based on comedogenicity scores — the methodology is not validated for humans
- −Replacing patch testing or dermatologist assessment of your specific skin reactions